**1. Introduction**

The conceptualization of the human body as a complex machine is not new among philosophers and scientists. Descartes, Hobbes, and La Mettrie, for example, are commonly associated with the "mechanical philosophy" of the 17th and 18th centuries [1–3]. But it was not until the first half of the 20th century that the mechanical conception of the human body took a different turn: If the human body is a complex machine, maybe the machine could be re-built and improved. This idea emerged in the aftermath of the World War I, not as a matter of philosophical inquiry, but as a matter of necessity and as a problem for policymakers.

As thousands of soldiers returned from the front with missing limbs, engineers and physicians had to work together in order to devise prosthetics limbs that might enable veterans to get back to work. A booklet published by the Red Cross in 1918, for instance, was entitled *Reconstructing the Crippled Soldier* [4]. The booklet contains several pictures of men using prosthetic limbs that functioned as tools such as pliers and hammers. The governments, especially in Germany, were eager to convince the new working force that the "scientific prostheses" [5]—as they were known—would make the disabled men even better and more productive than before [6–8]. Not everyone was convinced, though. In a short essay called "The Prosthetic Economy," published in 1920, the Austrian artist Raoul Hausmann sarcastically suggested that since the "prosthetic limb never gets tired," a "25-hour workday" should be adopted. He also went on to say: "The prosthetic man is therefore a better man, raised to a superior class thanks to the world war" [9]. The philosophical discussion on the ethics of human enhancement, as a topic for academic research, is rather recent, but the ethical concerns over the attempt to re-engineer the human body for the purpose of enhancement is not. It harks back to a broad societal debate that took place during the interwar years [6–8,10].

Now, 100 years later, policymakers, again, have to deal with technologies that have the potential to improve the human body. The conceptualization of the human body as a machine remains in place, but this time the machine is seen in a di fferent light. As the human brain (wrongly or not) is increasingly compared to a supercomputer, and the whole human genome has been sequenced and represented as a six-billion string of letters (A, T, C, and G), the mechanical conception defended in the past has given rise to a new image of the human body, to a vision of human beings not so much as composed of mechanical parts, but as a machine that can be understood at a molecular level, as a source-code that can be read and re-written by means of gene-editing tools. In this article, I intend to focus on the more recent development: I will focus on genetic engineering, rather than on prosthetic limbs, as a means to enhance the human body.

The philosophical debate on the ethics of human enhancement involves a distinction between two basic ideas, which have not always been carefully kept apart. One concerns the *means* of enhancement, the other concerns the *human capacity* to be enhanced. These are, for short, the "*enhancement by which means question*" and the "*enhancement of what question*." One can defend a pro-enhancement attitude as regards, for instance, the use of drugs such as modafinil to boost one's cognitive functions, but argue against the use of drugs for the purpose of enhancing one's physical capacities in professional sports. One can also have a pro-enhancement stance as regards the use of drugs to improve cognitive and physical capacities, but argue that human moral capacities should not be modulated by means of drugs. Or one can alternatively advance a broader pro-enhancement attitude as regards the use of drugs for improving one's cognitive, physical, and moral capacities, but still strongly oppose the use of genetic engineering to promote the enhancement of any human capacities. It is possible to think of some other combinations between the *means* of enhancement, such as prosthetic limbs, deep brain stimulation, or surgeries, and *human capacities* such as creativity, the propensity to form long-lasting affective bonds with other persons, or aesthetic appearance. Thus, compelling arguments for the use of one specific method of enhancement, targeted at one or more specific human capacities, may not be equally compelling as regards other means of enhancement, targeted at other human capacities. The attempt to advance an all-encompassing approach to the ethics of human enhancement, on the other hand, can obscure important issues or conflate problems that should be dealt with separately. In this article, I intend to examine the use of genetic engineering as a means of pursuing cognitive enhancement. "Genetic engineering" itself is too broad a concept, for it can refer to technologies that, as I intend to show later, give rise to di fferent ethical questions. I will focus here on two such technologies, namely gene editing (henceforth GE) and embryo selection (henceforth ES).

In addition to the "*enhancement by which means question*" and the "*enhancement of what question*," two further questions must be addressed in the human enhancement debate. One is the "*enhancement for whom question.*" This is especially important in the case of genetic engineering as a means of cognitive enhancement, for the persons who are going to be a ffected by the enhancement procedure do not yet exist. This means that they cannot give their consent to the use of techniques that will a ffect not only their personal identities as bearers of certain human capacities, but will ultimately also determine whether or not they are going to come into existence. This, as I intend to show later, raises ethical questions that do not emerge when we deploy other methods of human enhancement such as, for instance, drugs or prosthetic limbs.

Finally, a perennial question in the ethics of human enhancement debate concerns our very understanding of what human enhancement is about: *What is human enhancement* and how does it di ffer from *treatment*? In this article, I will not try to draw a clear-cut line between enhancement and

treatment, which could be applied to all cases involving the quest for human enhancement. Neither shall I attempt to advance a definition of human enhancement that covers every case that has been described in the philosophical literature as instances of human enhancement [11].1 For reasons I am going to spell out later, I suggest we should rather speak of "family resemblance," as Wittgenstein used the expression in the *Philosophical Investigations*, instead of proposing a very comprehensive definition of human enhancement [12].

I will speak here of "genetic cognitive enhancement" (GCE) to refer to GE and ES as procedures that, in the future, might enable prospective parents to increase the odds of having a child with increased intelligence. To the extent that one has increased intelligence, one can on average perform better in a wide range of cognitive domains such as, for instance, information processing speed, working memory, executive function, episodic memory, sustained attention, selective attention, etc. [13] (pp. 11–12), [14] (p. 279), [15] (pp. 53–54). One can of course have better cognitive performance without having increased intelligence in the sense I will focus on in this article. One can, for example, use some artificial intelligence device in order to improve information processing speed. One can even suggest that the device itself is an extension of the human mind, whether or not it is internal to the human body [16], (for Reference [17] see pp. 29–44). The device, however, cannot be genetically inherited. Although di fferent kinds of technologies can be deployed to improve cognitive performance, I will focus here only on GCE.

The question, then, is whether pursuing GCE, whether through GE or ES, is a morally acceptable goal. Di fferent moral theories and philosophical traditions, and even theological ideas, have been deployed in the philosophical debate on the ethics of human enhancement. On the other hand, far less attention has been given to public attitudes related to the development of human enhancement technologies. Some recent surveys on the public perception of human enhancement technologies and human genomics either focus too narrowly on a single country (United States) or on a single region (Europe), or they focus instead too narrowly on public perception of one specific technology (CRISPR, Clustered Regularly Interspaced Short Palindromic Repeats), and not on the public perception of human enhancement technologies at large [18–21]. In this article, I intend to focus on two recent surveys conducted by the SIENNA Project, of which the author of this article is a partner.2 The SIENNA Project has advanced probably the most comprehensive account of public attitudes towards human genomics and human enhancement to date. The SIENNA Project has also delivered a corresponding account of public perception of artificial intelligence and robotics, which I will not take into consideration in this article. The surveys were conducted in 11 countries, spanning across di fferent economic, cultural, and geographical landscapes (France, Germany, Greece, the Netherlands, Poland, Spain, Sweden, Brazil, South Africa, South Korea, and United States). The researchers employed the CATI method (computer assisted telephone interviewing) to interview one thousand respondents in each country [22,23].

### **2. Therapeutic and Non-Therapeutic Uses of Assisted Reproductive Technologies (ART)**

Assisted reproductive technologies (henceforth ART) have been developing at a rapid pace over the last decades. These technologies include, for instance:

1 For a recent review of the literature on human enhancement, see, e.g., Jensen and Nagel, 2018 [11].

2 The SIENNA Project (stakeholder-informed ethics for new technologies with high socio-economic and human rights impact) has received funding under the European Union's H2020 research and innovation programme under grant agreement No 741716. Kantar Public was commissioned by the University of Twente on behalf of the SIENNA project to prepare the surveys. Web: https://www.sienna-project.eu/.

Some of these technologies (CRISPR, GWAS, and AI) do not qualify as ART in their own right, but in combination with other technologies they constitute some of the most recent developments in the field of ART. Contraceptive pills (or other science-based contraceptive methods) qualify as ART to the extent that they provide a negative control over human reproduction. I call it "negative" because, in this case, one's primary intention is to avoid a pregnancy. One needs the technology, then, to avert the occurrence of a process that would otherwise naturally occur—or might naturally occur. Some technologies, on the other hand, provide a "positive" control over human reproduction. One needs the technology, then, to stimulate the occurrence of a process that, for some reason or other, would not otherwise naturally occur.

The positive control of human reproduction can be pursued for both therapeutic and non-therapeutic goals. The best known technology for the positive control of human reproduction is IVF. Human embryos generated by means of IVF do not have, though, equal chances of adhering to the uterus, or equal chances of developing into a healthy child. For this reason, the number of embryos generated in each IVF cycle is usually greater than the number of embryos eventually transferred into the uterus. Further development in the field of ART enabled the creation of the PGD, which is usually undertaken by collecting a few cells from a two- to five-day old embryo (blastocyt) for genetic analysis [24] (p. 34). PGD enable clinicians to screen embryos for health issues such as, for instance, Huntington disease, Marfan Syndrome, cystic fibrosis, and other known genetic disorders, before they can be transferred into the uterus. A new technique called time-lapse analysis has been recently employed to carry out a non-invasive assessment of patterns of development in embryos images in order to help clinicians to decide which embryos have the best prospect for transfer into the uterus [25–27]. And more recently still, time-lapse analysis has also been performed in combination with the use of artificial intelligence in order to further improve the assessment of embryo viability [28]. This procedure enhances the clinicians' ability to select an embryo that has more chances of adhering to the womb and developing into a healthy child.

Although most ART have been originally developed for medical reasons, it is clear by now that ART can be used for non-therapeutic purposes as well. Yet, in in some cases, a clear-cut distinction between "therapeutic" and "non-therapeutic" uses cannot be easily drawn. This is one of the reasons I will not propose a clear-cut criterion to distinguish enhancement from treatment in this paper. Contraceptive pills, for example, are a pharmaceutical product, but we do not ordinarily think of contraceptive pills as a sort of "medicine," for they are not usually meant to treat any disease. The IVF and PGD, on the other hand, can indeed be used to address human infertility, which the World Health Organization (WHO) understands to be "a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse" [29] (p. 1522). But when IVF and PGD are deployed to detect genetic disorders in human embryos, it is not entirely clear whether these technologies are being used for therapeutic purpose or as a device for selective contraception. If some genetic disorder is detected, clinicians and prospective parents have to decide whether or not to transfer the embryo into the uterus [30]. Treating the embryo, though, is not an option, at least not on legally and ethically acceptable grounds, as I am going to explain later. Sometimes, on the other hand, a distinction between "therapeutic" and "non-therapeutic" is more apparent: "Social egg-freezing" and GCE are two such cases. In the remainder of this section, I would like to describe briefly the former, before examining the latter more carefully in the next sections.

A woman may decide to resort to egg-freezing (or oocyte cryopreservation) in order to have some of her egg cells retrieved and frozen during the early years of her adult life. This enables her, for instance, to focus on her professional career while she is young, or while she waits until she has met the partner with whom she wants to have a child. Later, after she has secured the material means to give her child the best start in life, or met a partner she considers suitable to her, one or more egg cells, which had been previously frozen and stored in a fertility clinic, may be fertilized. For this, the woman does not even have to have a male partner. She can simply order a vial of semen from a private sperm bank and have it delivered to a fertility clinic. By the time the egg cells are fertilized, the woman may be less fertile than she was earlier, when the egg cells were retrieved from her ovaries. But this does not mean that she has become ill later, as fertility naturally decreases with age. The procedure, thus, is not used to treat an illness. It could be described, rather, as a technology for the enhancement of human reproduction, even though fertility is not a human capacity usually taken into consideration in the human enhancement debate. In the current literature on oocyte cryopreservation, it has become usual to distinguish "social egg freezing" from "medical egg freezing." The latter is deployed for medical reasons, when a woman has to undergo, for instance, cancer treatment, which may compromise her fertility after the treatment. Social egg freezing, on the other hand, is undertaken for non-therapeutic reasons [31–35].

Now, further development of new technologies such as IVG and CRISPR has the potential to give rise to other non-therapeutic applications of ART, including human enhancement. IVG has never been used for the generation of human gametes intended to start a pregnancy. CRISPR, on the other hand, has been reportedly used for the purpose of human reproduction only once, in 2018 in China, under circumstances that the Chinese government considered illegal, and the international community recognized as ethically unacceptable. The question, then, is whether further development of IVG and CRISPR might give rise to circumstances in which their use as ART, whether for therapeutic or non-therapeutic goals, might be considered ethically acceptable.

### **3. IVG and CRISPR as a Means of GCE**

Embryonic cells, in their early stages of development, can turn into any other types of cells. These cells are also known as stem cells. During the embryonic development, stem cells become specialized cells, such as nerve cells, heart cells, neurons, bone cells, and several other types of cells that make up the human body. Specialized cells are more commonly called somatic cells. Normally, somatic cells can only reproduce and become another somatic cell of the same type, but new technologies now allow researchers to turn somatic cells back into stem cells.  Because iPSCs can turn into virtually any other type of cell, they can also become reproductive cells or gametes. The generation of reproductive cells from iPSCs is known as in vitro gametogenesis (IVG), or sometimes also as "in vitro generated gametes," "artificial gametes," or "synthetic gametes" [36–43], (for Reference [44] see p. 4). IVG was carried out for the first time in Japan, in 2016, on mice. Researchers managed to generate several eggs cells from a small sample of mouse skin cells. The eggs cells were then fertilized in vitro, and the resulting embryos were used to start a pregnancy. The mice produced by the Japanese researchers were healthy and fertile [45]. Now, further research on IVG might perhaps enable clinicians to use this technology for the generation of human gametes in the future. The range of therapeutic and non-therapeutic applications would be enormous. But then, too, the number and scope of ethical concerns.

A man, for instance, could request the use of IVG to turn a tiny sample of his skin cells into egg cells and, thus, become a mother. In like manner, a woman could use IVG for the generation of sperm cells and, thus, become a father. Two men, or two women, could also have a child genetically related to them. Prospective parents who currently rely on IVF to start a pregnancy would also benefit from IVG. Instead of undergoing a series of hormone injections and a surgical procedure to obtain the eggs cells, the woman would only have to provide a small sample of her skin cells. This would make the entire IVF procedure far less invasive—and possibly less expensive—for the women [46] (p. 127).

IVG could also disrupt the market for human gametes. Some women who currently undergo the egg retrieval procedure do not intend to become mothers themselves. Their intention is, rather, to donate or sell some of their egg cells, which in turn can be used for research or for human reproduction. This practice, however, has raised some ethical concern relative to informed consent and exploitation of women [47], (for Reference [48] see p. 44). Men, too, can donate sperm cells for altruistic or pecuniary reasons [49–52], but prohibition of anonymous donation over the last years has led to a shortage of sperm cells in many sperm banks around the world. Recently, some bioethicists have suggested that the institutionalization of presumed consent for post-mortem sperm cells donation might be introduced as a solution for the problem relative to the current shortage of male gametes in sperm banks [53]. IVG of human cells, on the other hand, could reduce drastically the demand for donation of male and female reproductive cells, making access to human gametes much easier and cheaper for prospective parents and researchers.

Many sperm banks o ffer some information on the educational background or academic achievements of their individual donors. Prospective parents may use the information, then, as a rough predictor of the cognitive capacities of their o ffspring. But IVG, in conjunction with IVF and other technologies such as GWAS and AI, could provide prospective parents with a more reliable and effective method for assessing their chances of having a child with increased intelligence. The problem, though, is that the quest for GCE by means of IVG, in conjunction with IVG and GWAS, would require the generation of far more embryos than the amount of embryos that are currently generated in fertility clinics during every IVF cycle. The idea here is that the more embryos from the same parents one has, the more chances one also has of spotting one particular embryo with more odds of developing into a child with increased intelligence [39,40,46,54] (pp. 191–202), [55] (pp. 88, 93, 106–110).

Currently, PGD enables clinicians to screen embryos for some genetic diseases before implantation into the womb. Unviable embryos are discarded or, depending on local legislation, used for scientific research. But as genetic sequencing technologies becomes faster and cheaper, clinicians might be able to screen vast amounts of embryos from the same couple for both medical and non-medical issues. And as human intelligence itself is highly inheritable [56–58], clinicians could screen the embryos for this specific trait as well. There is not, though, one human gene for intelligence. It is believed that hundreds or thousands of di fferent genes, scattered at di fferent loci of the human genome, are involved in the expression of most psychological, behavioral, and physical human traits. It does not mean, of course, that genes alone determine all features one individual will ultimately have, for the expression of human traits very often depends on diverse degrees of interaction between genome and environment.

GWAS enable researchers to determine which regions of the human genome are associated with the expression of specific psychological, behavioral, or physical traits. This association can be measured and translated in terms of "polygenic scores," which is a probabilistic—thus not deterministic—estimation of the occurrence of a certain trait as the result of the influence of a large group of genes, [46] (p. 77). GWAS, thus, could help prospective parents and clinicians to select one embryo, amongst hundreds or thousands of embryos, with increased odds of developing into a child with higher intelligence. On the other hand, as Henry Greely points out, the vast amount of genetic data resulting from the assessment of polygenic scores could also lead prospective parents to make decisions that, in the end, might compromise the well-being of their child. How to decide, for instance, between Embryo1 and Embryo2 when Embryo1 has *x*% of having trait1 (IQ > 100), *y*% of developing trait2 (minor propensity to obesity), and *z*% of developing trait3 (propensity to depression), while Embryo2 presents di fferent polygenic scores for trait1, trait2, and trait3? The decision becomes increasingly more di fficult when the number of embryos to choose from is >100 and the number of eligible traits (both medically and non-medically relevant traits) is also very high [46] (pp. 193–196). In face of this "information overload"—as Sonia Suter aptly puts the problem—prospective parents would probably have to rely on the expertise of genetic counselors and computer algorithms to assess the polygenic scores their future o ffspring and adjust their preference for a specific trait like increased intelligence against medically relevant traits [46] (pp. 193–196), [54] (pp. 273–276). Once a decision has been made in favor of a specific embryo, the remaining embryos would have to be discarded.

Currently, depending on local legislation, unclaimed viable embryos can be "adopted." In 2017, for example, a woman in the United States gave birth to a baby that developed from an embryo that had been frozen for 24 years [59]. The mother was just over one year old when the embryo was generated. In adopting the unclaimed embryo, the woman became the gestational mother, and not the biological mother of the baby. Frozen embryos may remain unclaimed for several reasons: The couple may have divorced after the generation of embryos and, thus, they may have changed their minds as to become father or mother; or the father or mother (or both) may have died after the generation of the embryo; or the couple may have simply decided, after a successful gestation, not to use the remaining embryos for the generation of yet another child. Yet, even if many women would volunteer to adopt surplus embryos, a significant amount of embryos would still have to be discarded.

GCE by means of GE, on the other hand, would not require the generation of vast amounts of human embryos. Instead of selecting one among hundreds of embryos, clinicians could generate only one embryo by means of IVF—with or without the use of IVG. Then, the embryo could be edited with CRISPR to increase the chances that it will later develop into a child with increased intelligence. Thus, no embryo would have to be discarded. It must be emphasized, though, that at its current stage of development CRISPR is not considered a reliable kind of ART—neither for therapeutic nor non-therapeutic goals. Moreover, as mentioned earlier, thousands of genes are involved in the expression of human intelligence. Even if CRISPR becomes safe and reliable for therapeutic goals within the next years, it is still unclear whether it could be deployed for the purpose of GCE without the risk of o ff-target mutations and mosaicism [60]. Maybe other forms of human enhancement by means of GE will become acceptable before it can be used for cognitive enhancement, especially in areas where a clear-cut line between enhancement and treatment cannot be drawn.

Consider, for instance, the first actual use of CRISPR as a form of ART, which occurred in November 2018 in China. He Jiankui, a Chinese researcher, edited the genome of two twin girls at an early stage of embryonic development. He Jiankui's goal was to enable HIV positive men to generate children free of the HIV virus. The usual measure, in these cases, consists in treating the semen with a process known as sperm-wash before proceeding to IVF. This alone should have been enough to enable a man to generate a child uncontaminated by the HIV virus. However, He Jiankui's goal was not simply to guarantee the birth of an HIV-free child. His intention was to generate a child *immune* to the HIV virus. It is clear, then, that the procedure, in this case, was deployed for non-therapeutic reasons. It aimed at the genetic enhancement of two human beings. The whole procedure might be called "immune system genetic enhancement." Incidentally, some authors have speculated that the procedure might have also indirectly provided the twin girls with some degree of GCE [61,62].

The international scientific community vehemently repudiated He Jiankui's procedure, as it represented a clear violation of the ethical guidelines proposed by many international bodies over the last years [63–65]. However, the fact that the procedure was deployed as a means of human enhancement, rather than as a method of treatment for a genetic disorder, was not the main focus of criticism. Many articles, published shortly after He Jiankui announced the birth of the twin girls, did not even take notice of this aspect of his experiment. The main reason for criticism, as I have mentioned above, is the fact that CRISPR cannot yet be considered a safe and reliable kind of ART. It represents a threat not only to the well-being of children whose genome have been edited, but also to the well-being of their descendants.

Now, let us assume, for the sake of argument, that IVG and CRISPR will become available as reliable and safe kinds of ART within the next decades, and that further research on human genomics will provide solid knowledge on the genetics of human intelligence. Would there be good moral reasons, then, to favor one procedure or the other—ES or GE—for the purpose of GCE? Or should we entirely abandon the prospect of pursuing the ES and GE as kinds of ART, whether for therapeutic or non-therapeutic goals? In the next section, I will address these questions by comparing some of the ethical implication each of these technologies entails. Then I will focus on two reports recently published by the SIENNA Project on the public perception of scientific research on human enhancement technologies and human genomics.

### **4. Public Attitudes towards GCE**

How should we assess the ethical implications resulting from the use of technologies such as IVG and CRISPR for the purpose of GCE? Philosophical investigation into the principles of morality often relies on or starts with what *we* understand by concepts such as duty, virtue, or morality. Consider, for instance, Kant's statement in the Preface to the *Groundwork of the Metaphysic of Morals*:

"*In this work, I have adopted the method that is, I believe, most fitting if one wants to take one's route analytically from common cognition [gemeinen Erkenntnisse] to the determination of its supreme principle and in turn synthetically from the examination of this principle and its sources back to common cognition, in which we find it used*" [66] (p. 13).

We have to start somewhere, and our common understanding (or "common cognition") of some elementary moral ideas is a good starting point—indeed, perhaps the only one we have. But Kant also assumes that we all share a "common idea of duty and of moral laws" [66] (p. 7). The principles of morality, on this analysis, do not have to be agreed upon through a social contract, or through societal debate or similar decisional procedure. The principles have to be, rather, "brought to light" (*aufgeklärt*), for they already dwell human beings' "natural sound understanding" (*natürlichen gesunden Verstande*) [66] (p. 23). More often than not, though, *our* common understanding of moral concepts is *common* only to the extent that it is shared by some specific group of individuals, living in this or that century, in this or that country, as members of this or that social group. Our current understanding of moral duties and moral laws was certainly not shared, for instance, by Aristotle and other thinkers in the tradition of virtue ethics. And upon examination, we also realize that some ideas at the core of Kant's moral theory, such as the assumption that "ought implies can," are not shared by most people [67,68]. It might be argued, on the other hand, that Kant was not interested in a psychological account of our common understanding of moral concepts, but in a normative account. If someone, or even a large group of people, happen to lack "natural sound understanding," or does not recognize what the proper understanding of moral laws amounts to, that person or group of persons should be enlightened. On this account, public attitudes should not be taken into consideration in our analysis of the moral implications resulting from GCE, for moral reasoning itself cannot be enlightened by public opinion.

Philosophical investigation should certainly not pander to public opinion, as public opinion itself can be scrutinized, clarified, and corrected in the light of philosophical analysis, but neither should philosophical investigation underestimate the plurality of points of view at play in the moral debate on issues that matter for the public in general. This is especially important when philosophical expertise is deployed for the elaboration of public policies involving controversial issues, or for the regulation of technologies that may challenge our common understanding about what is ethically acceptable or morally deplorable. As Neil Levy aptly puts the problem:

"*Moral expertise is not the exclusive preserve of moral philosophers; instead, it is a domain in which a multitude of thoughtful people outside the academy make important contributions. The arena in which moral debate occurs is, accordingly, not limited to the peer-reviewed journals. Instead moral debate also, and almost certainly more importantly, takes place in newspapers and on television; in novels and films: everywhere moral conflicts are dramatized and explored*" [17] (pp. 309–310).

Recall that the first broad societal debate on the ethical implications from the quest for human enhancement by means of new technologies, as I mentioned at the outset of this paper, was mainly driven by stakeholders such as former soldiers, policy-makers, physicians, engineers, and artists rather than by philosophers. The methodological challenge for the assessment of ES and GE as means of GCE consists, then, in our capacity to take into consideration a variety of points of views. From the

point of view of a person who was generated by means of new kinds of ART, for instance, it may be important to know which procedure was used before his or her birth: ES or GE? If the embryo has been manipulated with CRISPR, the person has every reason to be grateful or, as the case may be, resentful for any changes that have been made in his or her genome. Suppose that the attempt to promote some cognitive enhancement by means of CRISPR has not been successful and that, for this reason, the person su ffers from some minor cognitive disorder such as for instance dyslexia—a condition that makes learning to read more di fficult. Let us call that person Person1. Person1 could hold her parents or the fertility clinic responsible for her su ffering, for the learning disability compromises her chances of success in achieving goals she would like to pursue in life. After all, if the GE procedure had not been used, Person1 would not have dyslexia. Now, let us suppose there is another person (Person2) who also su ffers from dyslexia and has the same degree of learning di fficulty as Person1. However, Person2 was not submitted to GE at an embryonic stage of development. Person2 was generated by means of a combination of IVG and IVF, along with hundreds of sibling embryos, and then selected for implantation into the uterus. All sibling embryos were discarded afterwards. Person2 may feel as frustrated as Person1, for the learning disability also compromises her chances of success in achieving goals she would like to pursue. But as some philosophers have noticed, unlike Person1, Person2 cannot simply say that some kind of wrongdoing was inflicted on her, or that she has the right to blame her parents or the fertility clinic for being a dyslectic person. For Person2, the only alternative would be not to have been selected in the first place and, thus, never to have been born. Darek Parfit and Thomas Schwartz are among the first philosophers who drew attention to this kind of paradox [69–71]. Schwartz called it the "fallacy of beneficiary-conflation" [71] (p. 7), but it is better known as the "non-identity-problem," as Parfit called it early in the 1980s [70] (p. 359). It is a paradox because a person may apparently present good reasons for wishing that a certain course of actions had never occurred in the past, but without that particular course of actions, which she would prefer had never occurred, she herself would not exist. One might argue, however, that from a legal point of view and as a matter of social justice, we should treat Person1 and Person2 the same way: If Person1 has a right to reparation due to the disorder caused by the GE procedure, then Person2 should also have the same right, as both cases, at least in the tradition of common law, can be characterized as a tort of wrongful life [72,73].3 A recent survey conducted online among 763 participants also suggests that most people believe that the "non-identity-problem" is not really relevant for an assessment of situations like this, involving the claims of Person1and Person2[74].

Alternatively, one might argue that in view of the ethical issues that underlie ES and GE, both procedures should be banned for the purposes of human reproduction. The only non-problematic form of human reproduction—one might suggest—is natural reproduction, that is sexual intercourse of a man and a woman, unaided by ART. However, banning the two procedures does not solve the problem, it just gives rise to a further ethical concern. Consider Person3, a fflicted by dyslexia just as Person1 and Person2. Person3, unlike Person1 and Person2, was generated naturally—her conception and birth did not involve the use of ART. Does Person3 have the right to blame her parents or clinicians for being a person who has dyslexia? The answer to this question will depend on the stage of technological development at the time that Person3 was conceived, and on the availability of the relevant technologies to her parents. For Person3, it could be frustrating to learn that her cognitive impairment could have been avoided by means of GE. From the perspective of Person3, it would have been better if her parents had indeed resorted to GE—even if it had involved some reasonable degree of risk. ES, on the other hand, would not have solved *her* problem, as she would not exist if some other embryo, free of dyslexia, had been chosen in her place. The choice for natural reproduction, therefore,

3 See e.g., Frasca [72] (p. 185): "The difference between wrongful birth and wrongful life is that in wrongful birth the parents bring the legal action and seek damages; whereas, in wrongful life it is the child who seeks damages and the child or the child's representative who brings the lawsuit." For a recent account of the legal issues surrounding the use of gene editing technologies within the context of American law, see Macintosh [73].

is not morally neutral. In circumstances where prospective parents have access to the relevant medical technologies, which allow them to have a child without a condition that, later, may compromise her well-being, the couple is morally accountable both for using the technology and for failing to use it. As Anthony Kenny puts the problem: "As technology increases our knowledge of evils and our power to remove them, it increases our responsibility for not removing them" [75] (p. 124).

For the time being, though, neither ES (in conjunction with IVG and GWAS) nor GE may be used as a kind of ART—whether for therapeutic or non-therapeutic goals. Leaving aside the question as to which technology will (from a purely technical point of view) mature first, there is some reason to believe that GCE by means of ES might become commercially available prior to GCE by means of GE. This would be a reason, then, to focus the ethical debate on ES rather than on GE.

One reason for the assumption that GCE by means of ES may become commercially available prior to GCE by means of GE is that some fertility clinics, especially in the United States, are now gradually advertising a wider range of medical conditions they can screen for [76–79]. Given the thin line between therapeutic and non-therapeutic uses of ART, it may be just a matter of time before intelligence becomes available for screening along with medical conditions such as diabetes, propensity to depression, or intellectual disability, even if the procedure is not overtly advertised as GCE, but rather as therapeutic measure to reduce the odds of having a child with some mental conditions that might compromise his or her well-being later in life. Some people might even argue that ES (whether or not in conjunction with IVG and GWAS) does not qualify as a human enhancement technology at all. Thus, from their perspective, they would be circumventing at least some of the ethical concerns involved in the quest for GCE. Their argument might also be explored by private companies and fertility clinics that cannot advertise their services as genetic enhancement because local legislation explicitly prohibits the pursuit of human enhancement at a genetic level. Whether they argue from genuine philosophical reasoning or from commercial opportunism is not the point. What matters is that they can argue that ES (unlike GE) does not do anything to the embryo. In the normal distribution curve for IQ scores, some people will naturally have IQ > 100 while others will have IQ < 100. GCE by means of ES consists in an attempt to optimize the chances of selecting an embryo that, among other things (e.g., having improved information processing speed, improved working memory, improved executive function, etc.) will develop into a child who will be in the former group. Thus, most definitions of "human enhancement," discussed in the philosophical literature, will not straightforwardly include ES as a means of human enhancement, for the "enhanced" person, in this case, has not been enhanced at all—i.e., the person herself has not been subjected to an enhancing process. The person, rather, developed from an embryo that had better odds of growing into a person with increased intelligence, quite independently of any modification in the embryo itself. If GCE requires a modification in the embryo, then ES clearly does not qualify as GCE. Yet, there is some reason to believe that GCE does not require embryo modification.

Some questions of social justice will emerge regardless of the procedure one chooses to increase the odds of having a child with increased intelligence. This is the reason why I have stated at the outset of this article that I would eschew the attempt to propose an all-encompassing definition of *human enhancement* and speak, instead, of "family resemblance." There are some relevant resemblances between ES and GE that enable us to consider both procedures as human enhancement technologies: (i) Both procedures enable prospective parents to improve the odds of having a child with increased intelligence, even if the child (or the embryo) is not modified when one opts for ES; and (ii) both procedures give rise to the same issues of social justice that require proper regulation from the relevant policy-makers. To see this, let us recall Person1 and Person2.

Person1 was born by means of GE and Person2 was born by means of ES. Let us suppose this time, though, that both procedures (GE and ES) were quite successful, as Person1 and Person2 have, among other things, an IQ of 145. Person1 and Person2 will be able to pursue goals that most people will not be able to pursue, at any rate not as e ffortlessly as Person1 and Person2. This in turn gives rise to questions of social justice: Is it fair that Person1 and Person2 have these advantages over most people, especially considering that neither Person1 nor Person2 did anything to deserve an IQ of 145? Some influential theories of justice suggest it would not be fair. As John Rawls put the problem in *A Theory of Justice*:

"*The unequal inheritance of wealth is no more inherently unjust than the unequal inheritance of intelligence. It is true that the former is presumably more easily subject to social control; but the essential thing is that as far as possible inequalities founded on either should satisfy the di*ff*erence principle*" [80] (p. 245).

Rawls is not suggesting here, of course, that intelligence itself should be redistributed in line with the di fference principle, but that the benefits that people obtain, thanks to their increased intelligence, should also benefit those who have been less fortunate in the natural lottery. After all, they have not deserved their talents—or lack of talents, as the case may be. It is a matter of pure chance that the natural lottery has allotted some people with more intelligence, or that some people were born into wealthier families.4 But Rawls also suggests, in a another passage, that maybe intelligence, too, could be directly subject to social control: "In the original position, then, the parties want to insure for their descendants the best genetic endowment (assuming their own to be fixed)" [80] (p. 92). The caveat in parentheses at the end of the sentence may be an indication that Rawls himself did not believe that the genetic endowment of our descendants cannot be changed. Maybe it can (Rawls must have thought) and if it can, it should be subject to social control in line with principles of justice, just in the same way inheritance of wealth is. Rawls, understandably, does not develop this topic further, dismissing it as a "speculative and di fficult matter" [80] (p. 92). But the prospect of using ES and GE as means of bequeathing our descendants a better genetic endowment makes this topic now less speculative, though certainly not less di fficult, than it was in 1971, when *A Theory of Justice* was published [81–84].5

If ES and GE become commercially available within the next decades, prospective parents may su ffer under the financial and emotional pressure to enhance their children, even if they would otherwise prefer not to enhance them. They may think, for instance, that it would be better to invest their savings in the education rather than in the genetic endowment of their future children. But if, on the other hand, most parents opt for the GCE, they may believe that a non-enhanced child will lag behind in the competition for goods such as university admittance or better positions in the job market. Now, the social pressure here is neither less nor more intense if prospective parents take into consideration that ES (unlike GE) will not modify the genome of their future o ffspring. Some prospective parents might perhaps favor GE over ES, if they believe, for instance, that abortion is morally wrong, for ES (unlike GE) will require the discarding of human embryos and this, too, may be perceived as equally wrong. But that will be a di fferent kind of pressure: A pressure to favor GE over ES while under the social pressure to enhance their future o ffspring. From the perspective of policymakers, ES counts as GCE, for ES gives rise to the same questions of social justice that GE does. But policymakers cannot take into consideration here only philosophical arguments. This might lead them to believe, for instance, that the non-identity problem requires that in cases involving wrongful life only the demands of people who were born through GE are valid. This would clearly conflict with the perception that most people, to whom policymakers are accountable, have of the problem. One of the surveys recently conducted by the SIENNA Project revealed, for example, that, on average, 79% of people across 11 countries believe that prospective parents will feel "pressured to have genetic

4 See Rawls [80] (p. 87): "Those who have been favored by nature, whoever they are, may gain from their good fortune only on terms that improve the situation of those who have lost out. The naturally advantaged are not to gain merely because they are more gifted, but only to cover the costs of training and education and for using their endowments in ways that help the less fortunate as well. No one deserves his greater natural capacity nor merits a more favorable starting place in society. But, of course, this is no reason to ignore, much less to eliminate these distinctions. Instead, the basic structure can be arranged so that these contingencies work for the good of the least fortunate. Thus we are led to the difference principle if we wish to set up the social system so that no one gains or loses from his arbitrary place in the distribution of natural assets or his initial position in society without giving or receiving compensating advantages in return."

5 Some authors have been trying to address these di fficulties over the last few years. See, e.g., [81–84].

testing done on their unborn baby," if genetic testing becomes increasingly common (see Scheme 1). This, too, raises questions of social justice, as many prospective parents may suffer emotionally or financially under the pressure to have their unborn children genetically tested. Some genetic testing may, for instance, reveal an underlying condition that affects not only the unborn baby, but also the living siblings (or the mother, or the father), who might perhaps prefer not to be informed about that particular condition [85]. It is a matter of societal debate to establish, then, at a national level, how policymakers are expected to address this question. No general philosophical moral principle can be deployed here without failing to do justice to public attitudes towards this problem.

**Scheme 1.** "Perceptions of the likelihood of parents feeling pressured to have genetic testing done on their unborn baby due to genetic test becoming more common" [23] (p. 35).

One might suggest now that the quest for GCE has implications for social justice at both national and international levels. At a national level, for reasons I have suggested above, and which are not new in the ethics of human enhancement debate: The rich will bequeath to their children not only their wealth, but also better genetic endowment. Their children, thus, will be better off both financially and cognitively. Lack of appropriate regulation at national level, therefore, might aggravate existing social inequalities. At an international level, countries that are in a position to develop research on human enhancement technologies and human genomics are on average richer than countries that do not have the capability to advance new knowledge and new technologies in these areas. Human enhancement, therefore, might aggravate social inequality at a global level as well.

Yet, some of recent findings of the research conducted by the SIENNA Project seem to suggest a different picture. Scientifically and technologically developed countries are not especially supportive of research on human enhancement technologies. Quite the opposite, as one of the reports puts it: "Overall, perceptions of human enhancement technology were most positive in South Africa, Greece and Brazil and least positive in Germany, the USA and France" [22] (p. 6). As far as support for cognitive enhancement is concerned, a similar pattern emerged: Brazil, South Africa, and Poland were most supportive, while the Netherlands, Germany, and France were least supportive of cognitive enhancement technologies (see Scheme 2). As for research to better understand the genetics

of human intelligence, Brazil, South Africa, and South Korea were most supportive, whereas the Netherlands, Germany, and France, again, were the least supportive countries in this area (see Scheme 3). As for research on human embryos in order to better understand "how to treat or cure health conditions," a different pattern emerged: Spain, the Netherlands, and Sweden were most supportive, whereas Greece, the United States, and Germany were least supportive (see Scheme 4).

**Scheme 2.** "Support for technology to make people more intelligent" [22] (p. 29).

**Scheme 3.** "Acceptability of conducting laboratory experiments on human embryos to understand how to increase human intelligence" [23] (p. 44).

**Scheme 4.** "Acceptability of conducting laboratory experiments on human embryos to better understand how to treat or cure health conditions" [23] (p. 45).

One possible implication of these findings is that the unregulated use of GCE technologies might perhaps lead to a greater increase of social inequality at a national level rather than at an international level. Countries such as the United States might perhaps even have more demand for GCE abroad, from countries that are more supportive of human enhancement technologies, than internally. But this tendency will also depend, among other factors, on national laws for the importation of genetic technologies and regulation for the range of procedures that fertility clinics are allowed to perform [86].6 This is a topic, though, I cannot delve into in this article, even recognizing that it is worth pursuing for a broader understanding of the ethics of GCE at an international level. My intention here was rather to call attention to the worldwide plurality of public attitudes towards human genomics and human enhancement, as recently surveyed by SIENNA Project, and suggest that these attitudes, too, should be taken into consideration in the debate on the ethics of human enhancement.


• **Temporal artery biopsy**

The gold standard for diagnosis of giant cell arteritis is Temporal artery biopsy (TAB). 10–20% of GCA can be biopsy negative, however a negative result does not rule out the condition [1–5]. The findings on temporal artery biopsy in GCA is characterized by inflammatory infiltration of the arterial wall by lymphocytes, macrophages and giant cells in about 50% of cases [1–5].


Laryngeal Airway Surgery

## **Chapter 9** Challenges in Tracheostomy

*Sapna S. Nambiar, Slimcy Shylen and Suma Radhakrishnan*

### **Abstract**

Tracheostomy is a life saving procedure of placement of a surgical airway. It is imperative for every medical personnel to be conversant with it as it helps secure airway, the first step in resuscitation when necessary. It is not only thorough knowledge of the anatomy of the neck and procedural technique but also the awareness of the unusual challenging situations likely during this procedure that can help avoid complications and enable one to be better prepared for any eventuality. This chapter aims to draw the attention to the likely challenges during tracheostomy including pediatric tracheostomy and percutaneous dilatational tracheostomy. An encounter with pseudoneurysm of the internal carotid artery helps understand the gravity of the likely challenges that a surgeon must be prepared to manage.

**Keywords:** tracheostomy, pediatric tracheostomy, percutaneous dilatational tracheostomy, pseudoaneurysms of internal carotid artery

### **1. Introduction**

Tracheostomy, the placement of a surgical airway, is a life saving procedure when endotracheal intubation is not an option or fails. Today with advancements in technology most patients can be easily intubated with very few absolute indications for tracheostomy. Patients' with severe maxillofacial injuries following road traffic accident and deep neck space abscess with impending airway obstruction are two of the glaring examples where emergency tracheostomy is the preferred option to secure airway. In the past, the primary reason for the placement of a surgical airway was emergent due to an impending airway obstruction, inability to intubate, or inability to ventilate with a bag mask [1]. A patient with stridor having a definitive contraindication for endotracheal intubation requires tracheostomy immediately. An otorhinolaryngologist is required many a times to perform this procedure either in the casualty or emergency operation theater itself. Now, elective placement is much more common with advances in emergency airway management. However it is not always possible to have the requisite expertise and advanced equipments required for the airway management. Also, there are several instances where the placement of a surgical airway is recommended, especially in the setting of large tumors of the upper aerodigestive tract, laryngotracheal injuries that preclude intubation, inflammatory swelling of the upper airway, bleeding in the airway, maxillofacial trauma, bilateral vocal cord immobility, and so on. Furthermore, in settings of known difficulty with intubation or certain facial dysmorphisms, an elective surgical airway is ideal [2]. Therefore it is not only necessary to have a thorough knowledge of the anatomy of

the neck and procedural technique but it is also equally essential to know the unusual challenging situations one can face during this procedure to avoid complications and be better prepared.

This chapter aims to draw the attention to likely challenges in tracheostomy which can help the surgeon be better prepared in such situations and it can help one to be fore warned prior to the procedure in order to avoid likely complications.

### **2. History of tracheostomy**

Tracheostomy is a procedure that has been performed as early as in 100 BC with documentation by the Greek physicians. It has gone through the mentioned 5 periods-

However with the advancements in technology and use of it in early diagnosis of airway lesions it has become possible to plan the definite treatment early and avoid unnecessary tracheostomies. The bronchoscopic guided intubation has further eased the procedure even in difficult scenarios. Therefore we now enter an era of dealing with challenges in the procedure; "period of challenges" as we prepare ourselves to be aware of the challenges and tackle them reducing mortality and morbidity.

### **3. Challenges during tracheostomy**

The neck dissection can be challenging in many situations like advanced laryngeal, hypopharyngeal malignancies, thyroid malignancies, deep neck space abscess, post radiation recurrence in neck etc. It is essential to ascertain the site of obstruction and evaluate the pulmonary status prior to the procedure. Tracheostomy would be futile in case of obstructions below the level of the planned stoma in the trachea. Based on the site; tracheostomy is classified as: High, Mid and Low tracheostomy. Usually it's the mid tracheostomy that is done at the level of the isthmus of the thyroid gland i.e. between 2nd and 3rd or 3rd and 4th tracheal rings. The low tracheostomy done below the level of the isthmus does carry the risk of injury to great vessels or damage to the pleura thereby resulting in pneumothorax and hence one must be careful. Usually the opinion of cardiothoracic surgeon is taken where sternotomy is required to approach the trachea like in enlarged thyroid with retrosternal extension or anaplastic thyroid

carcinoma with stridor. The ideal timing (early vs. late) and techniques (percutaneous dilatational, other new percutaneous techniques, open surgical) for tracheostomy have been topics of considerable debate. Based on evidence from 2 recent large randomized trials, it is reasonable to wait at least 10 d to be certain that a patient has an ongoing need for mechanical ventilation before consideration of tracheostomy [3]. However emergency tracheostomy is a life saving procedure required to be done within minutes with high complication rate as one does not have the luxury of time to ensure adequate preparation. This is where one must be well versed and equipped to deal with challenges.

### **4. Relevant anatomy**

The anatomy of the trachea must be understood with its relations to other relevant structures in the neck. The trachea is a 10 to 15 cm long fibro cartilaginous tube that begins at the inferior border of the cricoid cartilage at the level of the sixth cervical vertebra (C6), about 5 cm above the jugular notch. The inspection of the neck is important as patients with short neck, contractures post burns, post irradiated necks, severe cervical spondylosis, enlarged thyroid gland can pose difficulties during tracheostomy (**Figure 1**). The proper positioning of the patient ensuring good extension of neck is necessary to make the trachea more prominent and superficial to help in easy location and faster dissection especially during emergency tracheostomy. It is needless to emphasize the importance of good lighting in the field of dissection with an equally efficient assistant during the procedure as the structures must be well retracted to help locate the trachea in the midline. Midline dissection especially during emergencies can help one remain in the relatively avascular plain but this is not always true. The identification of the thyroid gland with appropriate dissection away from the plane of surgery by either hooking it up or in difficult cases ligating and dividing the isthmus can help reach the trachea faster. The pretracheal fascia is identified and confirmation of trachea done by aspirating air into a syringe with 4% lignocaine which can then be injected in case of procedures being done under local anesthesia. Once identified the inter cartilginous incision with or without removal of a part of the anterior tracheal wall is carried out to then introduce the tracheostomy tube of appropriate size while keeping the lumen open using the Trousseau's tracheal

**Figure 1.**

*Neck findings that can pose difficulties during tracheostomy (a) scar post burns, (b) short neck and (c) post irradiated neck.*

**Figure 2.**

*Tracheostomy tubes (i) Portex tube with inner tube and obturator & (ii) Jackson's metal tracheostomy tube with inner tube and obturator.*

dilator. The selection of the tracheostomy tubes either protex or metal depends on the indication for tracheostomy and the present clinical condition of the patient (**Figure 2**). All patients requiring prolonged ventilation, ICU stays with patient non responsive, anticipating need for positive pressure ventillation will require the cuffed portex tubes of proper size. In case of adult male patients its either 7.5 or 8 sized portex tube whereas in females its 7.5 or 7. However the Jackson's metal tracheostomy tube may be inserted in advanced laryngeal malignancy patients presenting with stridor where it is likely to be a permanent tracheostomy and patient requires to be sent home with the same after educating him and his relative on how to clean and use the inner tube. The requirement of suctioning can be avoided with cleaning by removing inner tube and reinserting it. However the metal tube can be an impediment in cases where there is bleeding with granulations around the stoma site, when an MRI is required etc. The selection of tracheostomy tube of appropriate size is important. Usually in intubated patients it is easy to ascertain the size but during emergency tracheostomy ensure that the tube with larger diameter is inserted so that chances of tube block in the early post operative period is minimized. Usually it's the cuffed portex tube that is used in adult patients with instructions to deflate the cuff at regular intervals. Now the portex tubes do come with the inner tube and hence is preferred over the metal tubes to avoid skin corrosion and granulations with better tolerability among patients. The maintenance of personal hygiene around the stoma site and cleaning of the tube must be explained well to avoid infection and stomal problems.

### **5. Salient features of a few of the challenges during tracheostomy**

i.*Pediatric Tracheostomy –* This is definitely a challenging area considering the tracheostomy technique. It was primarily indicated for inflammatory diseases (epiglottitis, abscesses or laryngotracheobronchitis) or trauma prior to early 1960s. At present, almost two-thirds of pediatric tracheostomies are performed in infants less than 1 year of age, the main indications been congenital or acquired laryngotracheal stenosis, prolonged ventilator support and regular pulmonary toileting for persistent aspiration in cases of pharyngotracheal discoordination. However severe anterior neck burns, vascular anomalies of lower neck and the need for high peak inspiratory pressures that may cause pnuemomediastinum/pnuemothorax are all contraindications to performing it.

Infant larynx is located at the levels of third to fourth cervical vertebra and it starts to descend by age of two to reach adult levels. The challenges in an infant larynx are based on its anatomy wherein up to ten tracheal rings lie in the neck in infants, it's one-third the size of adult larynx and thyroid notch lie behind the hyoid bone. The technical difficulties in performing a peadiatric tracheostomy is mainly due to the pliable cartilages of infant trachea which can make it difficult to identify from other tubular structures in the neck, thus increasing the possibility of injuring the major structures nearby like recurrent laryngeal nerve, esophagus etc. For peadiatric tracheostomies most palpable landmark is cricoid cartilage, unlike thyroid notch in adults. The location of tracheotomy in children for aspiration or prolonged ventilator support, is made at third or fourth tracheal rings. When indicated for incipient laryngotracheal stenosis (LTS) due to prolonged intubation, it must be at first tracheal ring to preserve as many normal tracheal rings distally as possible or low in the neck at sixth or seventh tracheal rings so as to spare sufficient number of normal rings between the stenosis and tracheostoma. The surgery is performed under general anesthesia with the airway secured where ever possible with an endotracheal tube or a rigid ventilating broncoscope. For cosmetic reasons a small horizontal incision is preferred which is then deepened through subcutaneous fat plane to strap muscles and bipolar diathermy used to cauterize small vessels in the surgical field. The anterior surface of trachea is exposed over 3 to 4 tracheal rings. The debate is still ongoing whether a vertical or horizontal tracheal incision, with or without flap should be made. However the vertical incision seems safer and preferred during all the procedures done at our institute. However tracheal stay sutures are placed or either sides and secured to either sides of chest or an inferiorly based Bjork flap transecting a single tracheal ring maybe taken and sutured to the inferior edge of skin to facilitate reinsertion of the tracheostomy tube while it is being changed or during accidental extubation. In infants accidental dislodgement of the tracheostomy tube is something that one must be careful about and hence the immediate post tracheostomy period is important with the infant requiring utmost care if possible by staff trained to do so. The smallest tracheostomy tube that ensures specifically adapted gas exchange in relation to child's age is selected. The postion of distal tip of tracheostomy tube, which should rest at least two to three rings above the carina, must be ensured hence the availability of appropriate sized tracheostomy tubes for infants is important. One ring Bjork flap is one of the ways to prevent anterior accidental subcutaneous dislodgement of the cannula.

ii.*Percutaneous Dilatational tracheostomy (PDT) -* The improvement in technique with adoption of percutaneous tracheostomy in the ICU patients has further revolutionized the procedure. Percutaneous dilatational tracheostomy (PDT) over a guidewire was invented by Ciaglia in 1985. This procedure has gained popularity owing to the easy execution of the same at the patients' bedside

#### **Table 1.**

*Contraindications of percutaneous tracheostomy.*

avoiding unnecessary and at times high risk transfers to the operation theaters and due to the cost- effectiveness. A recent meta-analysis of Putensen *et al*. in 2014 included 14 RCTs with 973 patients and found PDT to be associated with less incidence of stomal inflammation and infection but higher incidence of technical difficulties when compared to the conventional surgical tracheostomy [4]. This procedure as an emergency intervention requires an experienced surgeon and at any moment of time if required one must be prepared to convert to open procedure. There are definite contraindications as shown in **Table 1** which makes the patient selection process crucial. Proper patient selection and the wide use of ultrasound or bronchoscope can decrease failure rates and complications [5]. Though there are various techniques one should stick to the technique with maximum individual comfort as there is no evidence of superiority among various techniques.

### **6. Conclusion**

Tracheostomy is a procedure that has revolutionized recovery of critically ill patients especially those requiring prolonged ventilation. The knowledge of likely difficulties is essential to be able to circumvent them and provide a secure airway as early as possible. It is only in patients who cannot be intubated or in whom it is difficult to intubate that this procedure becomes valuable. The advances in technology and procedures have made intubation possible in almost all patients though it calls for need of expertise and right equipments. Tracheostomy has its challenges in indications, timing, procedure and post procedural care. After the mentioned five periods we are probably into the, "*period of challenges*" wherein the possibility of tackling the encountered difficulties is being dealt with. It is the beginning of the journey as we move over the uncharted sea and this is an attempt to highlight a few common difficulties encountered.

A case report below highlights one such challenging situation likely during an emergency tracheostomy. The importance of early recognition and timely meticulous management can help avoid serious complications and morbidity. The foresight to secure an airway, as intubation was not possible and avoid an incision and drainage helped diagnose a pseudoaneurysm. Pseudoaneurysms of the internal carotid artery (ICA) are rare and harbor potential risk of life threatening hemorrhage.

### **7. Case presentation**

*History* – A 62 year old lady with right side neck swelling having stridor was referred to our hospital. The patient a known diabetic, hypertensive with coronary artery disease was on medications for past 10 years. She gave history of dental pain with fever 10 days ago for which she consulted a doctor and was given medications. The fever and pain subsided but she developed a gradually progressive neck swelling on the right side with breathlessness that progressed to noisy breathing. She did not give history of blunt or penetrating neck injuries, voice change or dysphagia.

*Examination* – The patient had inspiratory stridor. Neck examination revealed a 5 cm x 3 cm firm to hard, tender swelling on the right side extending from just above the supraclavicular region to 1 cm lateral to the thyroid cartilage, laterally reaching upto the posterior border of the sternocleidomastoid. The examination of the oral cavity and oropharynx were unremarkable except for a carious right lower premolar tooth. On direct laryngoscopy the laryngeal inlet was found obstructed by a smooth bulge obstructing the glottis. The other clinical examination was found to be normal.

*Investigations & treatment* – The blood investigations were all within normal limits except for a raised total WBC count with neutrophilia. The primary concern was to secure an airway and hence an emergency tracheostomy was mandatory. The patient was shifted immediately to the operation theater and under local anesthesia tracheostomy was done. During the procedure after retracting the strap muscles the thyroid gland was found to be pushed by an unusually large mass on the right side. An attempt to retract or hook was futile with bleeding from the surface of the mass. The possibility of a vascular lesion in the region of the carotid sheath was suspected and hence meticulous and careful dissection was carried out to separate the mass. The thyroid gland was retracted medially and the mass held laterally for the visualization of the trachea. After confirming the position of the trachea the stoma was made between the third and fourth tracheal rings and 7.5 portex tracheostomy tube was introduced. The patient was comfortable post procedure and stridor relieved. USG neck was done which reported the possibility of a right internal carotid artery (ICA) pseudoaneurysm with a heteroechoeic collection compressing the right internal jugular vein (IJV). A CT angiogram was done which showed two pseudoaneurysms involving the right ICA with a peripherally enhancing hyperdense collection noted in the right carotid space surrounding the ICA and the distal common carotid artery, possibly a hematoma (**Figure 3**). Saccular pseudoaneurysms measuring 0.6 & 0.7 cm respectively causing complete airway compromise at C5 vertebral body level were noted (**Figure 4**). The opinion of the cardiovascular and thoracic surgeon was sought and endovascular stenting was advised as the definitive treatment option.

This case highlights one of the many challenges likely to be encountered during a tracheostomy especially when it is required to be performed as an emergency. "The eyes see what the mind knows" therefore awareness of this possibility helps the surgeon to be better prepared and avoid an on table catastrophe. The rupture of the pseudoaneurysm during the procedure can be life threatening and meticulous dissection can help avert an unusual adversity.

*Discussion-* The earliest known references to tracheostomy are made in the Rigveda published around 2000 BC. The term 'tracheotomy' was first published in 1649 by Thomas Fienus, and referred to the creation of an opening into the anterior tracheal wall to secure the airway. However, in 100 BC, Asclepiades of Bithynia was noted to be the first surgeon to perform an elective tracheotomy, but

**Figure 3.** *CT angiogram showing pseudoaneurysms involving right ICA.*

**Figure 4.** *CECT scan showing airway compromise due to the pseudoaneurysm (Rt).*

the first documented successful case dates back to 1546 and is accredited to Antonio Musa Brassavola, as the patient was thought to have an 'abscess of the windpipe'. Traditionally, the use of a tracheotomy was reserved for cases of airway obstruction [5]. The evolution of tracheostomy can be divided into five stages; the period of legend, fear, dramatization, enthusiasm and rationalization. In the early 19th century, tracheotomy was employed in the treatment of diphtheria and other infectious causes which lead to airway obstruction. In the 1930s, tracheotomy was performed in patients with bulbar poliomyelitis to facilitate access to the airway for the removal of secretions [6]. In the late 1940s to the early 1950s, many began trialing the application of positive pressure ventilation through a tracheotomy [7]. Also, in the 1950s, this

#### *Challenges in Tracheostomy DOI: http://dx.doi.org/10.5772/intechopen.105577*

surgical procedure was extended to multiple neurologic disorders including coma, brain tumors, multiple sclerosis, and so on. The growing use of tracheostomy led it to be considered as a routine procedure that was both effective and relatively safe, which sharply contrasts much of the previous thought equating tracheotomy to a 'pronouncing sentence of death' [8].

Special patient populations may benefit from early tracheostomy, including (1) high likelihood of prolonged mechanical ventilation (ARDS, COPD, failed primary extubation), (2) spinal cord injury and chronic neurologic disorders, and (3) traumatic brain injury patients and other patients with need for airways [9]. The operative technique of tracheostomy was refined by Chevalier Jackson. Studies have reported morbidity of 4–10% and mortality of less than 1% [10]. Though we have come a long way, the procedure is still with some hurdles. One such problem faced is that of an Internal Carotid artery (ICA) pseudoaneurysm which can make the procedure challenging. Pseudoaneurysms of the ICA are generally caused by trauma, with at least part of the aneurysm wall composed only of the adventitial layer or just by hematoma. It has a variety of causes including inflammation, trauma and various iatrogenic causes [11]. The age of presentation usually varies between 16 and 68 years. It may be asymptomatic and detected incidentally. Symptomatic pseudoaneurysms manifest with local or systemic signs and symptoms. Local effects of pseudoaneurysm (whether it is infected or not) are secondary to mass effect on adjacent structures causing compromise of function. This condition may manifest as a palpable thrill, audible bruit or pulsatile mass. Ischemia of the surrounding tissues due to vascular compromise may lead to necrosis of the overlying skin and subcutaneous tissues. Neurologic symptoms may develop secondary to nerve compression or ischemia. The compression of the adjacent vein may lead to edema and deep vein thrombosis. Thromboembolism is also a potential complication. The pseudoaneurysm may rupture leading to hemorrhage with its potential clinical sequel of life threatening shock. Pseudoaneurysm and deep neck space infection both present with posterior pharyngeal wall swelling, drooling, neck lump, hoarse voice or stridor. Clinically difficult to differentiate imaging modalities are required for the same. Investigations aiding in the diagnosis of pseudoaneurysm include Color Doppler sonography, contrast-enhanced CT (CECT), or MRI, and cervical angiography. Color Doppler shows swirling of blood flow within the pseudoaneurysm with a communicating channel to the parent artery (Yin Yang phenomenon) [12]. Ultrasonography (USG) is a valuable diagnostic tool for the detection of pseudoaneurysm. This modality is portable, readily available, inexpensive, fast, involving no ionizing radiations or renal toxic contrast material and non invasive. However it has limitations in assessing pseudoaneurysms of the deep arteries, moreover evaluations of vessels in fracture and hematoma may be difficult. Gray scale USG demonstrates hypoechoeic cystic structure adjacent to a supplying artery. CT angiography has advantage over other imaging modalities as it is not much operator dependant and has shorter acquisition time (<1 minute). Three dimensional CT angiography allows visualization of the lesion from all angles. It has high sensitivity and specificity in detecting arterial injuries. The MRI appearance of this lesion will vary depending on their size, age, extent of thrombosis and presence or absence of arterial occlusions. It shows flow void in a patent aneurysm and variable signal intensity in a thrombosed aneurysm [13]. A pseudoaneurysm generally appears on sectional MR images as small mass lesion that is closely contiguous with the patent artery but which projects outside its normal confines. The various treatment options for pseudoaneurysms include USG-guided compression, percutaneous thrombin injection, coil embolization, endovascular stent graft insertion, and surgery [14]. Lately, endovascular management has proven to be advantageous over surgical management. It is less invasive and is helpful especially when surgery is contraindicated due to various reasons [15]. It also reduces hospital stay, and has eliminated the need for surgical procedures under general anesthesia. The case discussed here is of pseudoaneurysm masquerading itself as a neck abscess causing airway compromise. Our patient presented with a gradually progressive neck mass associated with fever without any history of recent trauma or surgeries. The clinical picture along with the raised total WBC count made us suspect a deep neck abscess. There are reported cases of pseudoaneurysms mimicking neck abscess. The mass effect caused by the pseudoaneurysm was to such an extent that the laryngeal inlet was not at all visualized depriving the possibility of airway restoration by endotracheal intubation. Therefore the need to resort to emergency tracheostomy. This report underlies the need to treat neck swellings with caution and emphasizes the fact that though tracheostomy has evolved over centuries it's not without any challenges even in expert hands.

*Conclusion:* Tracheostomy is a common critical care procedure performed by surgeons with the otorhinolaryngologist called in for management of patients in stridor or with a neck mass. In emergency setting the risk is even more and hence it is necessary to be aware of likely conditions that could result in a catastrophe. Pseudoaneurysm of the ICA is definitely one such possibility that must be kept in mind as it can mimic a neck abscess and fatal rupture into the airway can be catastrophic. The knowledge of such a possibility with meticulous dissection would be required to secure an airway following which patient may be investigated and definitive treatment provided.

## **Author details**

Sapna S. Nambiar1 \*, Slimcy Shylen1 and Suma Radhakrishnan<sup>2</sup>

1 Government Medical College Kozhikode, India

2 Government Medical College Manjeri, India

\*Address all correspondence to<EMAIL_ADDRESS>
© 2022 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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## *Edited by Balwant Singh Gendeh*

This book presents selected topics on the larynx and related problems, providing insight into recent advances in the field. Airway and speech are of critical importance in our daily lives and contribute to our personal well-being and safety as well as our communication with others. However, it is only when disease or injury impairs its function that we appreciate the relevance of the larynx. This book presents new clinical and research developments as well as future perspectives on airway-related problems and lesions. Chapters discuss laryngeal examination, laryngo-pharyngeal reflux, vocal cord paralysis, laryngeal leukoplakia, and much more.

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