Optical Trocar to Facilitate the Pneumoperitoneum Creation in Bariatric Patients: Our Experience and Systematic Review
Conditions: Obesity, Morbid, Bariatric Surgery Candidate, Surgery-Complications
Sponsor: University of Foggia

 
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OPTICAL TROCAR TO FACILITATE THE 
PNEUMOPERITONEUM 
CREATION 
IN 
BARIATRIC SURGERY: OUR EXPERIENCE 
AND SYSTEMATIC REVIEW 
 
Running Head: Optical trocar in bariatric surgery 
 
 
 
NCT NUMBER not available. 
 
Date of document: 15/12/2023 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
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ABSTRACT 
 
INTRODUCTION: Laparoscopic bariatric surgery (BS) are becoming the most used procedure to treat 
the obesity. To facilitate safe initial access to the abdominal cavity, we insert an optical viewing trocar 
at the left hypocondrium. The aim of this study is to systematically evaluate all published data existing 
in the literature to analyze the safety of optical trocars in patients undergoing bariatric surgery and to 
compare these data with our experiences. 
 
MATERIALS AND METHODS: Our study retrospectively identified 403 consecutive obese patients who 
underwent laparoscopic bariatric procedure between 03 July 2017 and 31 December 2023 in our 
Department of Medical and Surgical Sciences, University of Foggia.   
 
RESULTS: Pneumoperitoneum was successfully induced in all of obese patients underwent bariatric 
surgery in our center using optical trocar access. The average age is of 40.35 ± 10.23 years, a mean 
BMI of 44.2 ± 12.21 kg/m2, a mean length of stay of 4.15 ± 2.31 days and a mean operative time of 
63.25 ± 10.45 min. Complications occurred in 5 patients (1.24 %): 4 postoperative bleeding from the 
port site and 1 intestinal perforation treated with direct suture. No conversion to laparotomy, no 
deaths.   
 
CONCLUSIONS: Our study highlights an important technique that can facilitate access into the 
peritoneal cavity in patients with obesity.  Although we observe a low complication rate extreme 
caution should always be used when utilizing this approach as it is not immune to major injuries as 
demonstrated. The most important safety factor is the surgeon’s experience and familiarity with the 
use of this technique. 
 
 
 
 
 
Key words: Sleeve Gastrectomy; Bariatric Surgery; Obesity; Optical Trocal; Laparoscopy; 
Pneumoperitoneum; Abdominal entry; Complications in laparoscopy; Laparoscopic insufflation. 

 
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INTRODUCTION 
 
Obesity is a worldwide epidemic and bariatric surgery has established itself as the most effective 
modality in combating the condition. Laparoscopy has become the preferred approach to bariatric 
surgery which is associated with more rapid wound healing and recovery and a decrease in certain 
complications, including pain, abdominal wall hernias, and wound infections when compared with 
traditional open surgery  1-3. 
Establishing pneumoperitoneum is classically performed using a Veress needle or the open Hasson 
technique, but obesity presents its own challenges when using these techniques, including thickened 
abdominal wall, variable anatomical landmarks, difficult and time-consuming dissection, air leak, 
inadequate pneumoperitoneum, subcutaneous emphysema, and difficulty with fascial closure 4,5. 
The use of a bladeless optical trocar before insufflation has been reported to be safe and effective in 
laparoscopic bariatric surgery [6, 7]. This trocar does not have a sharp shaft and abdominal entry is 
facilitated via a tapered tip with plastic tabs that dissect tissue when pressure is applied during 
insertion. A slight rotary movement of the trocar accompanies insertion. This movement separates 
the layers rather than cutting them, and the passage through each layer of the abdominal wall, as 
well as the entry into the abdominal cavity, can be continuously visualized through the clear plastic 
tip. 
The aim of this study is to systematically evaluate all published data existing in the literature to analyze 
the safety of optical trocars in patients undergoing bariatric surgery and to compare these data with 
our experiences. 
 
MATERIALS AND METHODS 
 
In this study we analyze data existing in the literature about the use of the optical trocars in patients 
undergoing bariatric surgery and we compare these data with our experiences. 
Our study retrospectively identified 403 consecutive obese patients who underwent laparoscopic 
bariatric procedure between 03 July 2017 and 31 December 2023 in our Department of Medical and 
Surgical Sciences, University of Foggia.   
This systematic review was conducted in accordance with the guidelines for Preferred Reporting Items 
for Systematic Review. The work has been reported in line with the PRISMA 2020 criteria [8]. 

 
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 We evaluated the quality and risk of bias of this Systematic Review using AMSTAR 2 checklist [9]. 
A systematic search was performed using electronic searches in EMBASE, Medline, Cochrane Library, 
and Psychinfo. Free text search in all fields was performed for "Sleeve Gastrectomy", "Bariatric 
Surgery", "Obesity", "Optical Trocal", "Laparoscopy", "Pneumoperitoneum", "Abdominal entry", 
"Complications in laparoscopy", “Laparoscopic insufflation”. The search included all study designs, 
with additional non-research captured studies identified through bibliographic cross-references. 
Published studies that contained outcome data for optical trocar during laparoscopic sleeve 
gastrectomy listed below were included. 
 
RESULTS 
 
A total of 403 patients underwent bariatric surgery in our center during this period of approximately 
5 years with an average age of 40.35 ± 10.23 years, a mean BMI of 44.2 ± 12.21 kg/m2, a mean length 
of stay of 4.15 ± 2.31 days and a mean operative time of 63.25 ± 10.45 min. Pneumoperitoneum was 
successfully induced in all of these patients. Complications occurred in 5 patients (1.24 %), with a 
mean BMI of 50.73 ± 2.31 kg/m2: 4 postoperative bleeding from the port site and 1 intestinal 
perforation treated with direct suture. No conversion to laparotomy, no deaths (Table 1).   
The technique involves the use of 4 12 mm trocars. Pneumoperitoneum is induced by a 0° optical 
trocar and maintained at 15 mmHg. The first trocar is usually inserted along the left mid-clavicular 
line approximately 2 fingers from the costal arch, another trocar along the left axillary line, a third 
trocar 1 cm to the right of the midline, and the fourth trocar along the right mid-clavicular line. A 10 
mm, 30 ° laparoscope is used. 
Figure (PRISMA Flow Chart) shows the study selection flowchart. Through the literature search, we 
identified 35 citations. We removed any duplicates and were left with 52 references. After excluding 
irrelevant reports by reviewing titles and abstracts, we then retrieved 23 full-text articles that were 
eligible. There were 8 articles with unrelated topics, 2 without full text, 2 conference abstracts, and 1 
non-English/Chinese literature excluded. Ultimately, 10 original articles were included, as shown in 
the study flowchart. (Table 2) [10-19]. 
 
DISCUSSION 
 

 
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Dingfelder described the direct trocar insertion technique 1978. He tested the trocar insertion 
technique without prior pneumoperitoneum. No technical failures reported among 301 patients 
included [20]. The technology was expanded in 1994 with the use of the optical trocar: Laparoscopy 
allows observation of all layers of the abdominal wall when accessing. These trocars are designed for 
use with blades or blunt-tipped trocars and their use to facilitate peritoneal access in obese patients. 
In our center during this period of approximately 5 years, pneumoperitoneum was always induced 
with an optical trocar in patients undergoing bariatric surgery. The mean operative time was 63.25 ± 
10.45 min, with a mean BMI of 44.2 ± 12.21 kg/m2, a mean length of stay of 4.15 ± 2.31 days. 
Complications occurred in 5 patients (1.24%), with a mean BMI of 50.73 ± 2.31 kg/m2: 4 
postoperative bleeding from the access site and 1 intestinal perforation treated with direct suture. 
This means that a high BMI can probably make it more difficult to visualize the layers of the abdominal 
wall during the induction of pneumoperitoneum with an optical trocar, favoring possible 
complications. 
Madan et al [10,11], Bernante et al [12], Amiki et al [19] with their studies concluded that initial trocar 
placement using a non-bladed trocar with an optical view without prior abdominal insufflation is safe 
and effective in morbidly obese patients. They didn’t observe any bowel or vessel injury during initial 
trocar placement. This method can be applied even in the super obese. 
Sabeti et al [13] in a series of 2207 patients underwent bariatric surgery using optical trocar for 
pneumoperitoneum has been observed 4 injuries occurred (.18%). All 4 patients had previously 
undergone abdominal surgery. Three required conversion to laparotomy and mesenteric repair, and 
the fourth was treated with laparoscopic pressure in the retroperitoneal fat.  
Sundbom et al [14,16] studied 11,744 patients undergoing laparoscopic gastric bypass. The analysis 
revealed 5 aortic lesions, all of which occurred in patients in whom an optical trocar had been placed 
before establishing pneumoperitoneum. Outcomes ranged from no major sequelae to bilateral lower 
extremity amputation and death. The risk of aortic injury was 0.043% overall and 0.091% when an 
optical trocar was used. 
Martìnez-Ubieto et al [15] analyzed Sixty obese patients underwent sleeve gastrectomy using a device 
equipped with 3-D optics that allows the surgeon to view the surgery in 3 dimensions using a specific 
monitor and wearing appropriate glasses. Only 1 intraoperative complication was recorded: 
retroperitoneal bleeding upon insertion of the optical trocar. 
Usman et al [17] presented a rare case of infrarenal abdominal aortic injury caused by the insertion 
of an optical trocar for bariatric surgery. Immediate recognition of the injury, implementation of life-

 
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saving maneuvers, timely resuscitation, followed by definitive repair of the aorta by the vascular 
surgeon saved this patient's life. The recovery phase was uneventful and the patient had no residual 
clinical problems during follow-up. 
Bucheeri et al [18] analyzed a case series of 821 patients who underwent bariatric surgery over 3 
years. Optical trocars successfully established pneumoperitoneum in all these patients. Complications 
attributed to optical trocar entry were found in 8 patients (0.97%), 3 males and 5 females. The average 
BMI of these 8 patients is 52.7 kg/m2. The complications encountered include 3 hepatic lacerations, 
4 mesenteric lesions and 1 laceration of the omental vessel. 
With this systematic review we observed a low complication rate reported in the literature using the 
optical trocar for the pneumoperitoneum, which predominantly include vascular or intestinal injuries. 
 
CONCLUSION 
 
Access to the abdominal cavity with an optical trocar can be considered a safe method to establish 
pneumoperitoneum in patients with morbid obesity, with the further advantage of not necessarily 
having to close the surgical breach. Our study highlights an important technique that can facilitate 
access into the peritoneal cavity in patients with obesity.  Although we observe a low complication 
rate extreme caution should always be used when utilizing this approach as it is not immune to major 
injuries as demonstrated. The most important safety factor is the surgeon’s experience and familiarity 
with the use of this technique. 
Our experience is perfectly in line with the literature, although this technique requires further studies 
to be certified 
 
 
 
 
 
 
 
 
 
 

 
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