In recent decades, surgeons have strived to improve the aesthetic outcomes of bariatric surgery through various techniques, including single-incision laparoscopic surgery (SILS). This method has been notably implemented in sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) procedures. Saber et al. and Huang et al. conducted case series studies on the SILS trans-umbilical approach in SG to minimize scar appearance and improve patient satisfaction rates, with favorable results reported [15, 16]. Additionally, the bikini line approach, described in sleeve gastrectomy and hiatal hernia repair (BLHHR) by the first author, demonstrated that this method is feasible, safe, and associated with less postoperative pain and high patient satisfaction with scar appearance [11, 12]. Consequently, we implemented the bikini line approach in one-anastomosis gastric bypass (OAGB); this technique had not been previously reported.

Forty-two out of 72 participants in the present study underwent BLOGB, while 30 patients underwent standard OAGB. Baseline characteristics showed no significant differences between the two groups regarding age, sex, BMI, and incidence of obesity-associated medical problems. Most of the study participants were female (79.2%), reflecting the current trend of higher prevalence of metabolic/bariatric surgery among women [17]. Both groups showed no significant differences in operative complications, hospital stay, weight loss, or resolution of obesity-associated diseases. However, the BLOGB patients had a longer mean operative time. They experienced less postoperative pain and reported greater satisfaction with the appearance of their scars.

The main challenge in applying this approach to perform a One-Anastomosis Gastric Bypass (OAGB) was primarily due to the placement of the ports through the lower abdomen, at a distance from the esophagogastric junction (EGJ). The use of long laparoscopic instruments and equipment allowed for convenient access to the EGJ with clear exposure and visualization of the hiatus. This facilitated the creation of an optimal-length gastric pouch and gastro-jejunal anastomosis. The low position of trocars at the bikini line did not hinder liver retraction or the placement of the first stapler on the lesser curve for pouch tailoring. The surgeon used the right lower bikini line trocar (Trocar 1) to hold the stomach and lift the liver simultaneously while using the umbilical trocar for all stapler fires. With sufficient articulation, the first staple was initiated at the lesser curve, and the great mobility of the stomach enabled the correct positioning of the stapler.

Moreover, the low placement of ports allowed direct access to the intestines, making intestinal measurement and the selection of a suitable jejunal loop length easier. Instrument maneuverability was adequate, and ergonomics were maintained throughout the procedure by ensuring an acceptable degree of spacing between trocars and optimal instrument triangulation (Figs. 1, 2). These findings confirm our previously reported results during BLSG and BLHHR [11, 12].

Scars from previous lower abdominal surgeries were observed in 5 (11.9%) of the BLOGB patients. These scars posed no difficulty during port placement at the bikini line. Initially, when designing this approach for sleeve gastrectomy, there were concerns that previous Caesarean sections might hinder port insertion due to underlying adhesions. However, it was found that most adhesions were minor, confined to the pelvis, and port placement was uneventful [11].

In the present study, the mean operative time (OT) for BLOGB patients was longer than that for those undergoing standard OAGB (110.71 ± 17.72 min vs 98 ± 18.27 min, p = 0.002), which may reflect the need for a longer learning curve. However, we believe that eventually, the OT will become comparable to that of the standard OAGB, as was the case following our experience with the bikini line sleeve gastrectomy [11]. Additionally, there was no significant difference in the length of hospital stay between the two groups (1–2 days, p = 0.762). Both the operative time and hospital stay for all participants were within acceptable ranges. Large patient cohort trials have reported a mean OT ranging from 86 to 110 min [18]. Similarly, the average length of stay for OAGB patients was previously reported to range from 1 to 5 days, with longer stays observed in patients with higher BMI and those undergoing the surgery as a revision [18,19,20]. The ASMBS has recognized OAGB as a procedure with a relatively short operative time and low complication rates [21].

Reduced postoperative pain and improved aesthetic outcomes are important concerns following surgical procedures. In the present study, the mean postoperative pain score following BLOGB was lower compared to the standard approach, possibly because lower abdominal scars tend to cause less postoperative pain than upper abdominal scars. Moreover, in the BLOGB group, the Patient Scar Assessment Questionnaire (PSAQ) demonstrated gradual improvement in scores, reaching optimal (lowest) scores by the 6-month follow-up visit. All patients expressed increased satisfaction with their scar appearance; 87.5% and 100% reported feeling very satisfied at 3 and 6 months post-surgery, respectively. In contrast, only 18.2% and 81.8% of OAGB patients expressed similar levels of satisfaction. The placement of scars below the abdominal folds rendered them inconspicuous, positively influencing scores, boosting satisfaction levels, and potentially having a positive psychological impact, thereby enhancing the overall quality of life. Another appealing aspect of this approach is the possibility of removing the scars during any future abdominoplasty, potentially making the procedure relatively scar-free. Aesthetic improvement is an important concern, especially among young women undergoing bariatric surgery. Another appealing aspect of this approach is the possibility of removing the scars during any future abdominoplasty, potentially making the procedure relatively scar-free.

No mortality or major complications were observed in the present study; only one patient in the OAGB group developed a surgical site infection (SSI). One might have anticipated a higher rate of port site infection in the BLOGB group, considering the low position of the scars within the abdominal folds. Although we did not observe leaks or hemorrhage in any participants, the potential for these complications in the early postoperative period following OAGB cannot be ruled out [5]. The incidence of leaks has previously been reported to range from 0.1% to 1.9%, and bleeding from the staple line has been reported in less than 3% of cases in OAGB [5, 21, 22]. Due to the shorter operative time and simplicity of the surgical technique, OAGB has shown fewer early and late surgical complications, ranging from 4% to 7.5% [21].

The mean percentage of excess weight loss (%EWL) and decrease in BMI observed during the follow-up visits were satisfactory and did not differ significantly between the two groups. The highest weight loss was noted at 12 months following surgery (90.88 ± 7.90% and 91 ± 7.11%, p = 0.474). These results are comparable to those reported in previous studies, which demonstrated outstanding weight loss outcomes following primary OAGB [5, 21, 23, 24].

Resolution or improvement of obesity-associated medical problems was observed in all participants, with no significant differences between the two groups. Improvement or remission started early, from the first postoperative month. At 12 months following surgery, resolution of T2DM was observed in all patients. Improvement in hypertension varied between 41.2% and 66.6% of the patients depending on the time interval following surgery. These results are comparable to those previously reported. Complete resolution or substantial improvement in obesity-associated medical problems following OAGB, including type 2 diabetes mellitus (T2DM), insulin resistance, hypertension, hyperlipidemia, liver steatosis, and obstructive sleep apnea, has been previously demonstrated [22, 24]. Lee et al. reported a 100% resolution in patients with metabolic syndrome at 2 years [20].