laparoscopic sleeve gastrectomy ( sg ) was introduced by gagner and colleagues as a first - step procedure to minimize surgical risk for super - super obese ( sso ) or high - risk patients , followed by either laparoscopic biliopancreatic diversion with duodenal switch or laparoscopic roux - en - y gastric bypass ( rygb ) .
sg is now established as a primary bariatric procedure apart from being a first - stage procedure in a planned bariatric approach for high - risk patients .
super obese ( so ) patients with a body mass index ( bmi ) 50 kg / m are a difficult - to - manage population because of the huge liver , leading to limited working space ; excessive torque on the instruments because of the thick abdominal wall ; comorbidities ; and high - risk anesthesia .
the management of patients with super - super obesity ( bmi 60 kg / m ) also remains a challenge .
robotic surgery may be a suitable alternative to the laparoscopic approach in so and sso patients .
robotic surgery allows for more precise manipulations and increased dexterity by downscaling the surgeon 's movements and filtering out physiological tremor .
it liberates the surgeon from torque on the instruments because of the thick abdominal wall and decreases the port - site trauma because of remote - center technology , thereby conferring improved ergonomic positioning .
furthermore , a true 3-dimensional view of the intra - abdominal anatomy with robotic surgery facilitates fine tissue dissection .
the main disadvantages associated with robotic surgery remain its high cost and longer setup time compared with the laparoscopic equivalent for many procedures . with increased experience
, it may be assumed that this setup time will be reduced , and in the future , operative costs may decrease as material prices are reduced .
this study evaluates our initial experience with and technique for robot - assisted sleeve gastrectomy ( rasg ) in morbidly obese ( mo ) and so patients .
a robotic platform was used for bariatric surgery starting in march 2012 at our well - established center of laparoscopic bariatric surgery .
the patients met the national institutes of health consensus criteria , as well as the institutional policies , for undergoing a bariatric procedure .
after the required training in robotic surgery , the surgeons initially performed a few simple cases such as cholecystectomy , hernia repair , and hiatal surgery before proceeding with bariatric procedures .
preoperative evaluation included bmi , anthropometry , routine blood parameters , nutritional markers ( vitamin b12 , folic acid , iron , ferritin , vitamin d3 ) , diabetes profile ( fasting blood glucose , hemoglobin a1c , fasting insulin , and c - peptide levels ) , lipid and thyroid profile , sleep study , upper gastrointestinal endoscopy , pulmonary function test , dobutamine stress echocardiogram , chest radiography , and ultrasonography of abdomen .
the following parameters were evaluated : patient demographic characteristics , body mass index ( bmi ) , comorbidities , total operative time ( further split into docking time and imbrication time ) , mean blood loss , conversions , perioperative complications and deaths , length of hospital stay , and excess body weight loss at 6 months after the procedure . the operative time was defined as the time from skin incision to skin closure , including any associated procedures .
the so ( bmi 50 kg / m ) subset of patients was compared with the mo patient group based on the previously mentioned parameters .
statistical analysis was performed using spss software , version 19.0 ( ibm , armonk , new york ) .
the patient is placed in the supine position with his or her legs by the side .
a 38f gastric calibration tube is used after induction to empty out the gastric contents and is kept in place to guide the sleeve formation .
pneumoperitoneum is created with a veress needle at palmer 's point up to a pressure of 15 mm hg .
all distances for port placement are measured after insufflation because measurements obtained before pneumoperitoneum is achieved may be misleading . pre - emptive infiltration of 0.5% bupivacaine is performed before incision at all port sites . the camera port ( 12-mm - diameter , 150-mm - long endopath xcel trocar ; ethicon endo - surgery , cincinnati , ohio )
is placed 20 cm below the xiphisternum slightly to the left of the midline under vision using a 0 10-mm laparoscope .
the ports for the robotic arms ( r1 , r2 , and r3 ) are established next .
r1 ( 8-mm da vinci cannula ; intuitive surgical , sunnyvale , california ) is placed at the left midclavicular line approximately 20 cm from the xiphisternum .
r2 ( 5-mm da vinci cannula ) is placed in the right hypochondrium at the midclavicular line , with care taken to ensure that the entry of the port is below the margin of the liver .
r3 ( 5-mm da vinci cannula ) is placed in the left flank at the level of the camera port .
the assistant port ( 12-mm - diameter , 100-mm - long endopath xcel trocar ) is placed between the camera port and r2 with a distance of at least 10 cm from both of them .
a 5-mm epigastric port is made and used to place a nathanson liver retractor for retraction of the left lobe of the liver ( cook inc . ,
a1 = assistant port ; n = nathanson retractor ; r1/r2/r3 = ports for robotic arms ; mcl = mid clavicular line ; sul = spino - umbilical line .
all 3 arms of the da vinci surgical system ( intuitive surgical ) are used .
the patient cart is brought from the head end of the patient , and docking is performed .
the instruments used for rasg are as follows : 8-mm da vinci harmonic ace curved shears ( ethicon endo - surgery , intuitive surgical , sunnyvale , ca , usa ) ( r1 , for gastrolysis ) , 5-mm bowel graspers ( r2 and r3 ) , and 5-mm needle driver ( r1 , for over - sewing staple line ) .
a 5-cm umbilical tape is used to measure the distance from the pylorus , and gastrolysis is performed along the greater curvature of the stomach using a harmonic scalpel ( ethicon endo - surgery , intuitive surgical , sunnyvale , ca , usa ) .
the short gastric vessels from the gastrosplenic ligament and posterior gastric adhesions with the pancreas are divided .
one can appreciate a bilaminar parchment  like membrane if one remains close to the stomach on the greater curvature .
care is taken to ensure that the bougie is withdrawn in the esophagus during this step ; otherwise , it can lead to difficulty in dissection around the hiatus .
the gastric calibration tube is pushed forward by the anesthetist and guided by the surgeon into the first part of the duodenum using bowel graspers .
rotation of the bougie by the anesthetist and correct amount of traction by the surgeon help in negotiating the pylorus .
this leads to the bougie nicely resting along the lesser curve of the stomach and helps in formation of an even sleeve .
a sleeve of stomach is created using an articulating stapler from the assistant port while the console surgeon applies traction on the stomach so that it lies in the right orientation .
sequential stapling first with a green load and subsequently with blue loads is performed while not being very snug to the bougie .
after the sleeve is formed , the staple line is imbricated using no . 2 - 0 polydioxanone running suture with a sliding loop at one end .
gastroscopy with saline solution immersion is performed in all cases to rule out any leak , bleed , or obstruction .
the patient is placed in the supine position with his or her legs by the side .
a 38f gastric calibration tube is used after induction to empty out the gastric contents and is kept in place to guide the sleeve formation .
pneumoperitoneum is created with a veress needle at palmer 's point up to a pressure of 15 mm hg .
all distances for port placement are measured after insufflation because measurements obtained before pneumoperitoneum is achieved may be misleading . pre - emptive infiltration of 0.5% bupivacaine is performed before incision at all port sites . the camera port ( 12-mm - diameter , 150-mm - long endopath xcel trocar ; ethicon endo - surgery , cincinnati , ohio ) is placed 20 cm below the xiphisternum slightly to the left of the midline under vision using a 0 10-mm laparoscope .
the ports for the robotic arms ( r1 , r2 , and r3 ) are established next .
r1 ( 8-mm da vinci cannula ; intuitive surgical , sunnyvale , california ) is placed at the left midclavicular line approximately 20 cm from the xiphisternum .
r2 ( 5-mm da vinci cannula ) is placed in the right hypochondrium at the midclavicular line , with care taken to ensure that the entry of the port is below the margin of the liver .
r3 ( 5-mm da vinci cannula ) is placed in the left flank at the level of the camera port .
the assistant port ( 12-mm - diameter , 100-mm - long endopath xcel trocar ) is placed between the camera port and r2 with a distance of at least 10 cm from both of them .
a 5-mm epigastric port is made and used to place a nathanson liver retractor for retraction of the left lobe of the liver ( cook inc . ,
a1 = assistant port ; n = nathanson retractor ; r1/r2/r3 = ports for robotic arms ; mcl = mid clavicular line ; sul = spino - umbilical line .
all 3 arms of the da vinci surgical system ( intuitive surgical ) are used .
the patient cart is brought from the head end of the patient , and docking is performed .
the instruments used for rasg are as follows : 8-mm da vinci harmonic ace curved shears ( ethicon endo - surgery , intuitive surgical , sunnyvale , ca , usa ) ( r1 , for gastrolysis ) , 5-mm bowel graspers ( r2 and r3 ) , and 5-mm needle driver ( r1 , for over - sewing staple line ) .
a 5-cm umbilical tape is used to measure the distance from the pylorus , and gastrolysis is performed along the greater curvature of the stomach using a harmonic scalpel ( ethicon endo - surgery , intuitive surgical , sunnyvale , ca , usa ) .
the short gastric vessels from the gastrosplenic ligament and posterior gastric adhesions with the pancreas are divided .
one can appreciate a bilaminar parchment  like membrane if one remains close to the stomach on the greater curvature .
care is taken to ensure that the bougie is withdrawn in the esophagus during this step ; otherwise , it can lead to difficulty in dissection around the hiatus .
the gastric calibration tube is pushed forward by the anesthetist and guided by the surgeon into the first part of the duodenum using bowel graspers .
rotation of the bougie by the anesthetist and correct amount of traction by the surgeon help in negotiating the pylorus .
this leads to the bougie nicely resting along the lesser curve of the stomach and helps in formation of an even sleeve .
a sleeve of stomach is created using an articulating stapler from the assistant port while the console surgeon applies traction on the stomach so that it lies in the right orientation .
sequential stapling first with a green load and subsequently with blue loads is performed while not being very snug to the bougie .
after the sleeve is formed , the staple line is imbricated using no . 2 - 0 polydioxanone running suture with a sliding loop at one end .
gastroscopy with saline solution immersion is performed in all cases to rule out any leak , bleed , or obstruction .
a total of 35 patients ( 15 female and 20 male patients ) with a mean bmi of 48.17  11.7
the bmi ranged from 33 to 82.6 kg / m , with 3 patients having a bmi > 80 kg / m .
the mean operative time was 116.3  24.7 minutes , and the mean docking time was 8.9  5.4 minutes . the mean time taken to imbricate the staple line was 21.4  6.4 minutes . mean blood loss was 19.36  4.62 ml , and there were no complications , conversions , or perioperative deaths in the series .
a steep decline in operative time and docking time was observed after the initial 10 cases .
we believe that the operating room team surpassed the learning curve for robotic bariatric surgery by the 10th case .
the team was already well - versed in laparoscopic bariatric procedures and could adjust to the new system fairly quickly .
the so group was compared with the mo group regarding patient demographic characteristics , bmi , and comorbidities ( table 1 ) , as well as perioperative outcomes , complications , and weight loss ( table 2 ) .
the comparison showed no significant difference in operative time ( p = .145 ) , blood loss ( p = .523 ) , and length of hospital stay ( p = .213 ) .
the excess body weight loss at 6 months ' follow - up was also not significantly different between the 2 groups .
perioperative outcomes , complications , and ebw loss in morbidly obese versus super obese patients ebw = excess body weight .
laparoscopic bariatric surgery , especially in so patients , presents a complex situation in which the surgeon has to deliver the best results despite compromised technology . with the advent of robotic technology ,
its application to bariatric procedures may eliminate certain limitations such as torque on rigid instruments because of the thickness of the abdominal wall and difficulty in dissection or suturing in a limited working space because of a heavy liver and excess omental fat .
it also provides for a stable and ergonomically comfortable platform with 3-dimensional vision and precise movements without any tremor .
sg , on the other hand , is considered a relatively simple procedure compared with rygb .
however , there are certain peculiarities in sg ; for example , it uses a long staple line with a potential to leak , and precise and safe dissection is required in the area of the left crus and hiatus to entirely mobilize the fundus . compared with laparoscopic surgery
, robotic surgery offers the possibility of endowrist application ( intuitive surgical ) , and this action facilitates the over - sewing of the staple line . over - sewing of the staple line
was accepted by most of the surgeons ( 95% ) participating in the international sleeve gastrectomy expert panel .
any leak with sg is a high - pressure leak and is difficult to manage compared with an rygb leak .
these difficulties become more pronounced when operating in an so patient because of limited working space .
so and sso patients are high - risk candidates , and sg is considered the first step in a 2-stage procedure or , more and more often , is performed as a single - stage procedure . from a surgical point of view , so patients remain a difficult population to manage , usually with outcomes slightly less favorable than those for mo patients .
there have been comparisons of robot assistance in rygb in so patients versus mo patients , and there are studies that state that rasg is a safe and feasible operation . however , there are no or very few studies comparing the perioperative outcomes of using a robot for sg in so patients versus mo patients . the results of rasg for the so group versus the mo group were compared to look for any advantages provided by the robotic system in the so group . in our experience , the outcomes in both the so and mo groups were the same , with no complications in either group .
this occurred despite the fact that there were a few very high - risk sso patients in this series , including 3 patients with a bmi > 80 kg / m .
in addition , a robotic system helps in precisely over - sewing the staple line ( as is the routine practice in our center ) even in sso patients with a severely limited working space .
thus , using a robotic system may help overcome many difficulties in so patients and enables the surgeon to perform a similar procedure to that in mo patients with equal precision , similar time requirement , and little or no extra effort .
we believed that during introduction of robotic surgery to a bariatric program , sg was a relatively simple and safer procedure to start with .
it enables the whole team to become accustomed to the setup of the robotic system , docking , and troubleshooting .
once the team is comfortable with rasg , it can proceed to robotic rygb and revision surgical procedures . in this series
the learning curve for rasg was 10 procedures for a team well - versed in laparoscopic bariatric surgery and well - trained in handling the da vinci surgical system .
after 10 cases , our docking time , setup time , and console time plateaued with a < 5% change in the operative time .
first , the study had a small sample size , and patients were not randomized .
yet , it described our initial experience with rasg and tried to address issues such as safety , outcomes , and the learning curve .
second , the study included the learning curve of the team , which may have increased the mean operating room times .
third , the study did not analyze the additional cost of using a robot , but we believe that clinical outcomes are much more important and that costs are bound to decrease with time . in addition , the study did not compare rasg with laparoscopic sg , and such a comparison is required to ascertain the real benefit of using a robotic system .
in addition , the ease and precision with which the staple line is imbricated are definite advantages .
rasg can act as a good procedure to introduce robotics in a bariatric surgery center before going on to perform rygb and revision procedures .
the learning curve for rasg is about 10 cases for an established bariatric surgery center .
the real advantages in comparison with the laparoscopic approach are still being debated and require further studies for the subpopulation of so patients .
 background and objectives : this study evaluates our technique for robot - assisted sleeve gastrectomy for morbidly obese and super obese patients and our outcomes.methods:a retrospective analysis of patients who underwent robot - assisted sleeve gastrectomy at a single center was performed . 
 the procedure was performed with the da vinci si hd surgical system ( intuitive surgical , sunnyvale , california ) . 
 the staple line was imbricated with no . 
 2 - 0 polydioxanone in all cases . 
 the super obese ( body mass index 50 kg / m2 ) subset of patients was compared with the morbidly obese group in terms of demographic characteristics , comorbidities , operative times , perioperative complications , and excess body weight loss.results:a total of 35 patients ( 15 female and 20 male patients ) with a mean body mass index of 48.17  11.7 
 kg / m2 underwent robot - assisted sleeve gastrectomy . 
 of these patients , 11 were super obese and 24 were morbidly obese . 
 the mean operative time was 116.3  24.7 minutes , and the mean docking time was 8.9  5.4 minutes . mean blood loss was 19.36  4.62 ml , and there were no complications , conversions , or perioperative deaths . when compared with the morbidly obese patients , the super obese patients showed no significant difference in operative time , blood loss , and length of hospital stay . 
 there was a steep decline in operating room times after 10 cases of robot - assisted sleeve gastrectomy.conclusion:this study shows the feasibility and safety of robot - assisted sleeve gastrectomy . 
 robotic assistance might help overcome the operative difficulties encountered in super obese patients . 
 it shows a rapid reduction in operative times with the growing experience of the entire operative team . 
 robot - assisted sleeve gastrectomy can be a good procedure by which to introduce robotics in a bariatric surgery center before going on to perform roux - en - y gastric bypass and revision procedures . 
INTRODUCTION
MATERIALS AND METHODS
Operative Technique: RASG
RESULTS
DISCUSSION
CONCLUSIONS