Single-port sleeve gastrectomy: a comparison between transumbilical and left hypochondrium approaches

Data from all consecutive patients who underwent SPSG in our bariatric institution between January 2019 and June 2022 were prospectively collected (after informed consent by patients and institutional review board approval) and retrospectively analyzed. This study was performed according to the Strengthening the Reporting of Observational Studies in Epidemiology (Strobe) guidelines. Operative and postoperative outcomes were analyzed in patients with more than 1-year follow-up.

All patients underwent a meticulous preoperative examination by a multidisciplinary team as previously described [5]. Patients were eligible for surgery if they had a body mass index (BMI) of 40 kg/m² or higher, or a BMI between 35 and 40 kg/m² with significant comorbidities according to French guidelines [13].

A TU approach was performed under two conditions: if the left quadrant incision site was less than 5 cm from the umbilicus in patients with a BMI < 50 kg/m².

Among 514 patients who underwent primary bariatric surgery between January 2019 and June 2022, 65 patients with missing clinical and/or radiological reports were excluded from the study; thus, the total number of patients enrolled in our analysis was 449. A TU approach was used in 136 patients (30%). The mean follow-up time was 24 ;months.

The median age was 40 years [31–49] and the median BMI was 41.4 kg/m² [38.2–45.8]. There were 93 males (20.7%) males and 356 (79.3%) females. The two groups did not differ in age, whereas, as expected, patients in the TU group were more frequently women (92.6%) and had a lower BMI (P < 0.0001). Again, as expected, patients in the LHC group had more comorbidities. The demographic and clinical characteristics of the patients are listed in Table 1.

Mean operative time was 75 min [62–95]. Operative time was significantly longer in the LHC group (80 min vs. 64 min, P < 0.0001). In both groups, SPSG was performed successfully without requiring additional ports, conversion to laparotomy and without significant (> 100 ml) intraoperative bleeding. Median length of stay was 3 days. Operative and postoperative outcomes of patients in LHC and TU groups are depicted in Table 2.

Over the years, our group has attained favorable outcomes by promoting and standardizing the SPSG technique, especially through the LHC approach. This approach is uniformly applied to all patients, regardless of comorbidities including those with superobesity [15], or previous abdominal surgery such as liver transplantation [16] and candidates for kidney transplantation [17]. It offers direct access to the surgical site, avoids digestive interposition, and ensures optimal alignment for stapling. This approach also facilitates standardization, aiding young surgeons who gain independence after approximately 20 procedures.

However, in response to the rising demand for minimally invasive cosmetic procedures, we have adopted the TU approach for selected patients. The TU access simplifies antral dissection and initial stapler application but presents challenges with dissection of the gastrosplenic ligament and final stapler applications due to distance and limited visual perspective. Overall, the LHC access is recommended for beginners and challenging cases, while TU access is suitable for select patients and experienced bariatric surgeons, but less conducive to routine practice.

Meticulous patient selection is crucial for achieving favorable outcomes in this technically demanding procedure. In this retrospective study, we observed that 93% of patients in the TU group were female, with lower BMI and fewer comorbidities. Existing literature reveals highly varied selection criteria. Maluenda et al. [10] recommended the TU approach for patients with a median BMI of 35 kg/m². Lakdawala et al. [18] suggested it primarily for females with BMI less than 40 kg/m², and Wang et al. [19] indicated feasibility even in patients with BMI ≥ 50 kg/m². Our selection criterion is based on the distance between the left costal margin and the umbilicus, which is indirectly linked to BMI but also to gender, or more precisely to fat distribution. By using this precise selection criterion, we were able to carry out all the procedures via the TU approach without the need to add a trocar or convert to laparotomy, and without increasing the risk of intraoperative and early postoperative complications.

There was a 16-min longer operative duration in the LHC group. Several factors could explain this difference. Firstly, entry to the abdominal cavity at the umbilicus is easier due to the presence of finer subcutaneous tissue and a single-layer aponeurosis. Secondly, abdominal closure is faster in the umbilical cohort, whereas in the LHC cohort, closure is more complex due to the presence of a two-layer aponeurosis. However, the intraabdominal operative time was similar.

There was no difference in the length of stay between the two cohorts (3 days). Hospitalization and discharge follow an internal protocol, except for patients who have experienced complications. A fast-track protocol was recently implemented in our department, using a multimodal strategy to facilitate faster discharge.

This analysis demonstrates similar 1-year postoperative results between the two cohorts in terms of weight loss and resolution of comorbidities. This demonstrates that the TU access executed with adequate specific instruments in well-selected patients, does not result in the creation of a suboptimal sleeve that would impair long-term postoperative outcomes.

Since the early 2000s, SILS has become popular among many surgeons and is being applied to a broad range of bariatric and non-bariatric procedures. However, the rate of IH remains a major concern. A single but significant parietal incision might promote postoperative IH, particularly when the single-trocar is placed at the umbilicus, due to the inherent anatomical weakness of this area. The real incidence and prevalence of IH following bariatric surgery are not well defined in the literature. Some studies report a near 3% rate of IH following laparoscopic bariatric surgery [20], while others report rates as high as 24% and even 37% when detected by ultrasonography within 9 months after the bariatric procedure [12, 21, 22]. Several reasons can explain this heterogeneity: first, the focus on other postoperative outcomes, particularly weight loss. Second, clinical examination has proven to be unreliable for evaluating trocar-site hernias in bariatric patients, as most IH are not visible or palpable. Moreover, there’s a lack of long-term follow-up and the absence of imaging (ultrasound, CT scan) in the follow-up protocols in many bariatric centers. In a meta-analysis, Connel et al. [12] reported an increased risk of IH in those undergoing SILS (odds ratio 2.83). This is in line with results published by Antoniou et al. [23]. However, the majority of studies included in these meta-analyses [12, 23] focused solely on laparoscopic cholecystectomy, which may not be an ideal indication for this type of surgery. Indeed, the gallbladder can be removed in most cases through a 10- or 12-mm trocar incision during conventional laparoscopic cholecystectomy. Therefore, removing the specimen does not require making a single but large incision, as is done with SILS. In the present study, the global incisional hernia rate was 14% in the total cohort (65/449 patients) which is consistent with previous data reported by our group [24]. This rate may seem high to many surgeons but must be analyzed in context. Indeed, this result is comparable and equivalent to those from well-structured published studies [20, 22, 25] that have used specific imaging for the assessment of IH in conventional bariatric surgery. The most concerning aspect was the rate of IH (25%) in the TU group, whereas it was less 10% in the LHC cohort, even though surgery was performed in the latter group on patients with a higher BMI and more comorbidities. It’s interesting to note that 60% of patients who were scheduled for SPSG using the TU approach were found to have an umbilical hernia. More specifically, of the 82 patients who underwent TU surgery in the presence of an umbilical hernia, 25 developed an IH (30.5%), whereas of the 54 patients who underwent surgery without an umbilical hernia, only 9 developed an IH (16.7%). This difference was not statistically significant (P = 0.0732). However, it is conceivable that a certain number of small umbilical hernias were not detected during dissection and placement of the single-trocar which may overestimated the actual rate of postoperative IH in the “no umbilical hernia group.” Indeed, the prevalence of umbilical hernia in patients with obesity is notably higher compared to the general population. In a study published by Wang et al., the prevalence of umbilical hernia in adult surgically naive patients was around 65% based on CT findings [26]. After multivariate logistic regression analysis, age, asthma, and higher BMI were statistically the most significant risk factors [26]. The placement of preventive/curative mesh during TU approach seems imperative. Actually, current guidelines [27‐29] for abdominal wall closure recommend the placement of prophylactic mesh during elective laparotomy closure in patients with obesity and clean or clean-contaminated operative fields. Systematic placement of a parietal prothesis in all patients with obesity operated by SILS is therefore probably necessary, given that this endoscopic surgery is in fact performed through a very small laparotomy incision. In our approach, the specimen (an intact lateral stomach) is removed through the single-port’s protective skirt which greatly reduces the risk of contamination of the operating field. We previously published a prospective study [24] (PRISM) suggesting that the prophylactic placement of a retromuscular mesh patch during SPSG through the LHC decreases the occurrence of postoperative IH and could be proposed for high-risk patients (BMI ≥ 45 kg/m²) without increasing the rate of postoperative surgical site infection. However, the placement of preventive mesh through the umbilicus in patients with obesity could be more challenging. The Intraperitoneal Onlay Mesh (IPOM) technique is an option, but the higher cost of bifacial mesh in potentially contaminated surgery settings could limit its use. The preperitoneal and retromuscular approaches allow placing a "low-cost" mesh. However, it requires a large dissection, which can be difficult in bariatric patients, particularly in the umbilicus. Onlay mesh placement might be an interesting strategy to strengthen the fascial closure. Based on the present results, we decided in the first instance to implant a parietal prothesis in all patients who presented with an umbilical hernia during surgical exploration and opted for IPOM which are more costly but relatively easy to fit. Depending on the results, we could discuss extending the indications to all patients operated using the TU approach.

This study has several limitations that should be highlighted. First of all, it was conducted by a team where SPSG is the standard for all patients undergoing sleeve gastrectomy. Therefore, the results cannot be easily generalized. Additionally, this study is subject to confounding bias due to its non-randomized methodology. Lastly, the overall benefit of SILS is debatable and needs to be demonstrated, especially considering the potential higher cost of preventive mesh placement. Improved cosmesis remains the primary benefit of the single-port approach for sleeve gastrectomy. Some may argue that such consideration is trivial in the context of bariatric surgery. However, esthetic improvement is often a significant concern in this population, particularly among young women, as evidenced by the increasing demand for SPSG in our department. Moreover, the psychological impact of this benefit may also contribute to enhanced patient quality of life and adherence to postoperative compliance. Large prospective multicenter studies are needed to evaluate the other potential benefits of SPSG, which have yet to be fully elucidated.

In this retrospective study, we have demonstrated the feasibility of SPSG through two access routes: the LHC and TU approaches. Like any minimally invasive procedure, SPSG requires specific instrumentation and a dedicated learning curve. The LHC approach has been standardized and is routinely feasible for all patients eligible for LSG. Conversely, the TU access can be offered to selected patients. However, it is associated with a significantly much higher rate of IH. Prophylactic mesh placement could be considered to reduce the incidence of this complication. Our results should be validated by large, prospective, randomized studies, which should also evaluate the additional benefits of this type of procedure in bariatric surgery.