A 22-year-old male patient, known case of seizure disorders, cognitive impairment, and hypothyroidism, diagnosed to have constrictive pericarditis. He was on treatment with multiple antiepileptic medications and implanted VNS for seizure control. After a detailed preoperative anesthesia checkup, a neurology, neuropsychiatry consultation was advised to get an advice to deal with a patient on VNS, Cyberonics, Inc., (NASDAQ: CYBX) during the perioperative period. He was posted for an elective pericardiectomy surgery. During the history, tuberculosis, as one of the most common causes for constrictive pericarditis has been ruled out.
His 2D echocardiography revealed, thickened calcific pericardium involving right ventricle free wall and along inferolateral wall, presence of septal bounce, restrictive left ventricular filling, dilated inferior vena cava, central venous pressure approximately 15 mmHg, prominent expiratory diastolic flow reversal in hepatic veins normal right and left ventricle systolic functions and pulsus paradoxus, which supported the diagnosis of constrictive pericarditis. His hematology, biochemistry, and thyroid functions were within normal limits. On viewing the chest X-ray along with the cardiopulmonary findings, it was found that the device is located in the left infraclavicular area [Figure 1]. Moreover, to add confusion at a first glance, it was easy to appreciate it as a pacemaker, unless the history and other details were known.
Neuropsychiatry consultation was taken for his mental retardation and it was described as "cognitive dysfunction" in which patient has an incapacity to so sign the consent, despite being major from the age, and therefore in this case, all the consents was signed by the relatives.
Neurology consultation was taken, to know the precautions for safe handling of the device during and after surgery. As per the neurologist, the device needed to be reprogrammed and stopped before the surgery so the electromechanical interference with the cautery could have minimized. It was also advised by the neurologist, to consider the use of only bipolar cautery during the surgery. The use of bipolar cautery can be easily accepted in any other surgery but in cardiac surgery, monopolar cautery is required for an effective hemostasis from the sternotomy and intrathoracic sites. The monopolar cautery can disturb the functioning of the vagus nerve stimulator device, and therefore, it is important not only to reprogram the device but also to keep the cautery pads as far as possible from the device implantation site. Similarly, at the end of surgery, the device should be reprogrammed to its preprocedural mode so that it can continue to deliver the benefits to the patient, it is intended for.
Usually, a well-controlled patient on antiepileptic medications can be managed according to a routine protocol but, if a patient is on implanted VNS, it requires familiarity with the device functioning and its perioperative implications. The aim of knowing the mechanism of VNS functioning is to keep the perioperative period uneventful.
In our case, whole perioperative period remained uneventful and after an adequate recovery, the patient was discharged on the same antiepileptic medications with the VNS mode resumed as it was in the preoperative period.