Obesity and its related metabolic disorders have become a major global health burden. For patients with moderate-to-severe obesity, or obesity complicated by type 2 diabetes, obstructive sleep apnea, fatty liver disease, hypertension, and other comorbidities, metabolic and bariatric surgery remains one of the best supported long-term treatment strategies. The 2022 ASMBS/IFSO guidelines broadened the indications for metabolic and bariatric surgery, increasing the number of patients considered eligible for operative treatment and placing greater emphasis on safety, standardization, and patient experience [1][2].

LSG has become one of the most widely used bariatric procedures worldwide because it has a relatively straightforward operative pathway, avoids gastrointestinal anastomosis, produces reliable weight loss, and has a well-characterized complication profile. Conventional LSG is usually performed with four or five trocars to mobilize the greater curvature, divide the fundus, create the gastric sleeve with linear staplers, and retrieve the specimen. With the development of single-port platforms, articulating instruments, magnetic retraction, improved fascial closure, and enhanced recovery pathways, surgeons have explored whether fewer abdominal wall access sites can reduce parietal trauma, improve scar appearance, and increase patient satisfaction.

In patients with obesity, however, single-port or reduced-port LSG is not simply a matter of using fewer trocars. A thick abdominal wall, enlarged left hepatic lobe, abundant visceral fat, difficult fundal exposure, and restricted working angles can turn port reduction into a complex problem involving exposure, traction, stapling geometry, specimen extraction, and closure of a larger fascial defect.

Since 2019, the literature has shifted from asking whether single-port LSG is technically possible to asking which patients may benefit, which access routes are safer, how port-site outcomes should be reported, and whether long-term risks have been underestimated. Recent systematic reviews and meta-analyses increasingly treat single-port, reduced-port, magnetic-assisted reduced-port, three-port cosmetic, and other trocar-layout strategies as a continuum of access optimization rather than as a simple binary comparison between single-port and multiport LSG [3]-[5]. This review therefore discusses single-port and reduced-port LSG together, while maintaining a clear distinction between direct single-port evidence, reduced-port or trocar-layout evidence, and broader safety evidence for LSG.

PubMed was used as the primary database. The search covered publications from January 1, 2019, to June 8, 2026. Core search terms included single-incision, single-port, single port, single-site, single site, reduced-port, reduced port, trocar, port-site, sleeve gastrectomy, and laparoscopic sleeve gastrectomy. The core search string was: (“single-incision” OR “single-port” OR “single port” OR “single-site” OR “single site” OR “reduced-port” OR “reduced port” OR trocar OR port-site) AND (“sleeve gastrectomy” OR “laparoscopic sleeve gastrectomy”). Additional searches used terms related to sleeve gastrectomy leak, GERD, Barrett esophagus, bariatric surgery guidelines, robotic sleeve gastrectomy, and perioperative metabolic and nutritional management.

This article is framed as a scoping review rather than a systematic review. Thirty-one PubMed-indexed studies were included. Eighteen addressed single-port surgery, reduced-port surgery, magnetic-assisted reduced-port surgery, trocar layout, or cosmetic incision strategies; thirteen were used to define the broader safety context of LSG, including indications, leak, GERD, Barrett esophagus, long-term outcomes, robotic platforms, and perioperative management. Studies that were remote from LSG, could not be verified through PubMed bibliographic information, or were isolated case reports unable to support a review-level argument, were excluded.

The search and reporting process was guided by the logic of the PRISMA extension for scoping reviews (PRISMA-ScR), although this article was not registered as a systematic review protocol. Titles and abstracts identified through the search strategy were screened first for relevance to laparoscopic sleeve gastrectomy and access reduction. Full texts were then assessed for whether they provided direct evidence on single-port, single-incision, reduced-port, magnetic-assisted, or trocar-layout strategies in LSG, or whether they supplied essential background evidence on LSG safety outcomes. Study selection was performed by the author; uncertain records were retained only when the bibliographic information and relevance to the review question could be verified through PubMed. This process yielded the final set of 31 studies cited in the review.

Terminology in this field remains inconsistent. Single-port LSG may be described as single-port sleeve gastrectomy, single-incision laparoscopic sleeve gastrectomy, single-site sleeve gastrectomy, or transumbilical single-incision sleeve gastrectomy. In broad terms, these approaches attempt to complete LSG through one main incision. Reduced-port LSG generally refers to procedures using fewer than the conventional four or five trocars, including three-port, two-port, magnetic-assisted, or specially retracted approaches. Because definitions differ across studies, heterogeneity in meta-analyses is unavoidable [3]-[5].

From a clinical standpoint, fewer ports do not automatically mean less trauma. A larger transumbilical fascial defect may concentrate local tension and place greater demands on secure closure. Conversely, a three-port or bikini-line strategy may not be a strict single-port operation, but it can offer a pragmatic balance among scar concealment, operative triangulation, and abdominal wall safety. The more useful framework is therefore not single-port versus multiport, but a spectrum that includes conventional multiport LSG, reduced-port LSG, magnetic-assisted reduced-port LSG, left hypochondrial single-port LSG, and transumbilical single-port LSG. These approaches should be compared by exposure quality, operative safety, incision-related outcomes, and patient-reported benefit.

Studies published after 2019 support a cautious conclusion: in experienced centers and selected patients, single-port or reduced-port LSG can be completed safely and can achieve short-term outcomes close to those of conventional multiport LSG. Tranchart et al. found broadly comparable short-term safety and early recovery between single-port and conventional LSG after propensity-score matching, although single-port surgery generally required longer operative time [6]. Khidir et al. extended the comparison to 5-year weight loss, comorbidity resolution, and cost, suggesting that single-port LSG can become a stable clinical pathway rather than only a cosmetic variant [7].

Technical series further show that the success of single-port LSG depends less on the incision itself than on exposure and retraction. Wang et al. described transumbilical single-incision LSG assisted by a stomach retractor in superobese patients, emphasizing the need to reconstruct effective traction under single-port conditions [8]. Borjas et al. compared magnetic-assisted reduced-port LSG with conventional LSG and suggested that magnetic retraction may help reduce port number while preserving exposure quality [9]. Together, these studies point to a central principle: port reduction can become a real clinical advantage only when it does not weaken fundal exposure, His-angle dissection, or staple-line quality.

Systematic reviews and meta-analyses provide a higher level of evidence but also reveal important limitations. Ataya et al. found limited differences in several perioperative outcomes between single-incision and conventional multiport LSG, but the included studies varied in sample size, port definitions, surgeon experience, and endpoints [5]. Jiang et al. showed that trocar number and placement may influence operative efficiency, exposure, and incision-related outcomes [4]. Gutiérrez-Ramírez et al. reported that reduced-port techniques are generally feasible, but whether they consistently reduce pain, improve cosmesis, or lower complications remains uncertain [3]. Current evidence therefore supports feasibility, but not universal superiority.

Since 2025, research questions have become more refined. Abdallah et al. compared transumbilical and left hypochondrial single-port LSG, showing that the access route may influence cosmetic results, efficiency, and incision risk [10]. Widjaja et al. examined transumbilical single-port LSG according to height and BMI, underscoring the impact of body habitus on technical suitability [11]. Zidan et al. proposed the PSPOSO checklist to standardize reporting of port-site placement and outcomes in metabolic and bariatric surgery [12]. These studies indicate that the field is moving from technical demonstration toward standardized reporting and individualized selection.

The clinical value of single-port or reduced-port LSG must rest on uncompromised safety. Perioperative safety includes operative time, bleeding, leak, stenosis, reoperation, readmission, and mortality. Comparative studies and meta-analyses generally suggest that severe complications are not clearly higher than with conventional multiport LSG in experienced centers [3]-[7]. This conclusion should be interpreted carefully, however, because many studies are retrospective, single-center, and subject to selection bias. Outcomes from expert teams may not be generalizable to patients with very high BMI, a thick abdominal wall, marked hepatomegaly, or complex previous upper abdominal surgery.

Staple-line leak remains one of the most serious complications of LSG. Port number does not directly determine healing of the staple line, but instrument angle, traction direction, completeness of fundal mobilization, and staple-line tension can all be affected by trocar layout. Iossa et al. emphasized that leak is associated with patient factors, technical factors, and perioperative management [13]. Ma et al. showed that the value of intraoperative leak testing must be interpreted within specific workflows and risk stratification [14]. Single-port or reduced-port LSG should therefore never compromise bougie calibration, fundal dissection, hemostasis, staple-line assessment, or closure quality.

Cosmesis is the most visible appeal of single-port and reduced-port LSG. Fewer incisions, or scars hidden in the umbilicus or bikini line, can improve patients’ acceptance of postoperative appearance. Recent studies of three-port bikini-line LSG and aesthetic-focused bikini-line LSG suggest that incision-position optimization can improve satisfaction with appearance [15][16]. These findings are clinically relevant because patients care not only about complication rates, but also about body image, scar visibility, and recovery experience.

Cosmetic benefit is also the outcome most easily overinterpreted. Transumbilical single-port access usually requires a larger single fascial incision, and patients with obesity often have thicker abdominal walls, higher local tension, and less favorable wound-healing conditions. Short follow-up may underestimate trocar-site hernia. Muñoz-Leija et al. highlighted the importance of standardized fascial closure in reducing port-site complications after LSG [17]. Cosmetic outcomes should therefore be reported together with trocar-site hernia, chronic incision pain, infection, seroma, and need for repair. A study that reports only 30-day morbidity or length of stay cannot fully evaluate the benefit-risk profile of a transumbilical single-port approach.

Pain and enhanced recovery also require cautious interpretation. Fewer trocars may reduce abdominal wall injury in theory, but traction through one larger incision, specimen extraction, and fascial closure may offset some of this advantage. Future studies should include visual analogue pain scores, analgesic consumption, time to ambulation, length of stay, time to return to work, scar satisfaction, and validated body-image measures instead of using port number as a proxy for what patients actually experience.

From the perspective of weight loss and metabolic improvement, single-port or reduced-port LSG remains LSG. If sleeve geometry, fundal resection, antral management, bougie size, and staple-line quality are equivalent, port number alone should not substantially alter long-term mechanisms of weight loss or metabolic remission. Available mid-term data suggest that single-port LSG can achieve weight loss and comorbidity improvement close to conventional LSG [7]. However, if reduced access compromises exposure, leaves residual fundus, twists the sleeve, or changes staple-line trajectory, long-term weight control and reflux risk may be affected.

Recent studies of modified three-port LSG, antrum preservation versus resection, omentopexy, and banded versus non-banded LSG show that long-term outcomes after LSG are influenced by multiple technical details [18]-[21]. Single-port and reduced-port studies should therefore report more than port number. Important operative details include distance from the pylorus at the first staple firing, bougie size, fundal management, staple-line reinforcement, sleeve shape, postoperative reflux, and need for reintervention (Table 1).

Table 1. Selected evidence on single-port, reduced-port, and access-optimization strategies in LSG.

GERD is one of the most important long-term issues after LSG. Single-port or reduced-port access is not itself the main determinant of GERD, but insufficient exposure may indirectly increase reflux risk by affecting His-angle dissection, fundal resection, or sleeve geometry. Reviews of GERD after LSG and studies on de novo Barrett esophagus emphasize the need for long-term symptom and endoscopic surveillance [22][23]. Magnetic sphincter augmentation has also been explored for refractory GERD after LSG [24]. These data show that evaluation of single-port and reduced-port LSG must extend beyond early incisions and pain to include reflux symptoms, endoscopic findings, proton-pump inhibitor use, and revisional surgery.

Current evidence supports selective use rather than broad routine adoption. Patients who may be better candidates for single-port or reduced-port LSG include those with relatively lower BMI, moderate abdominal wall thickness, no marked enlargement of the left hepatic lobe, no complex upper abdominal surgical history, a clear preference for better cosmetic outcomes, and willingness to undergo long-term follow-up. Reduced-port experience in Asian patients suggests that body habitus and abdominal wall characteristics influence feasibility [25]. Large single-port series using left hypochondrial or transumbilical access also indicate that access selection is closely tied to center experience [26][27]. In patients with very high BMI, central obesity, abundant male-pattern visceral fat, severe hepatomegaly, dense adhesions, or complex GERD, conventional multiport LSG remains the more prudent option.

These selection factors should be interpreted as expert-derived practical considerations and proposed reporting domains rather than validated contraindications. They are intended to guide shared decision-making, study design, and transparent reporting until prospective evidence defines more reliable selection thresholds.

The learning curve also limits generalizability. Single-port LSG requires familiarity with coaxial manipulation, instrument crossing, restricted traction, and closure of a single larger incision. Many favorable reports come from high-volume or expert centers. Future studies should report surgeon experience, case-sequence position, additional trocar use, conversion rate, and learning-curve subgroup outcomes. In clinical practice, adding a trocar when exposure is inadequate should be considered a safety strategy, not a technical failure.

The evidence base remains limited in several ways. Recent strict single-port LSG studies are still mainly retrospective and single-center, often with modest sample sizes. Terminology is heterogeneous, with single-port, single-incision, reduced-port, three-port, and magnetic-assisted approaches used inconsistently. Outcomes are unevenly reported across operative time, complications, pain, cosmesis, and cost, while long-term trocar-site hernia, GERD, Barrett esophagus, and revisional surgery are underreported. Selection bias is substantial because single-port or reduced-port surgery is often offered to patients who are already more suitable for access optimization. Economic evidence is also sparse, although device cost, availability, and training requirements strongly affect scalability.

The safest interpretation at present is that single-port and reduced-port LSG are feasible refinements of conventional multiport LSG, not fully proven replacements for it. Clinical adoption should depend on patient selection, technical training, standardized port reporting, meticulous fascial closure, and long-term follow-up (Table 2).

Table 2. Practical selection and reporting framework for single-port or reduced-port LSG.

Future work should advance in three directions. First, technical reporting should be standardized and should include incision location, number of ports, single-port platform, liver-retraction method, additional trocar use, bougie calibration, distance from the pylorus, staple-line reinforcement, and fascial closure. Second, endpoints should extend from early operative measures to patient-reported outcomes and long-term safety, including pain, scar satisfaction, body image, trocar-site hernia, GERD, Barrett esophagus, weight regain, nutritional risk, and revisional surgery. Third, study design should improve through multicenter prospective studies or high-quality real-world cohorts comparing single-port, reduced-port, and conventional multiport LSG under standardized pathways with prespecified subgroup analyses.

Robotic platforms, magnetic retraction, articulating instruments, and more mature single-port access systems may further improve the working conditions of single-port LSG [28]. Studies of left-sided LSG and long-term comparisons between LSG and Roux-en-Y gastric bypass provide additional context for technical choices beyond port optimization [29][30]. Perioperative nutritional, metabolic, and nonsurgical support guidelines also remind us that access refinement cannot be separated from comprehensive bariatric care [31]. Valuable technical progress should be safe, effective, reproducible, teachable, and perceptible to patients; reducing ports is only one part of that standard.

Evidence from 2019 to 2026 suggests that single-port and reduced-port LSG can serve as minimally invasive refinements of conventional multiport LSG in experienced centers and selected patients. The current literature supports feasibility and acceptable short-term safety, but does not yet prove stable, universal, or long-term clinical superiority. Recent work has shifted from feasibility toward access-route selection, trocar layout, incision-related complications, patient-habitus matching, and long-term safety. For clinical practice, the key question is not whether fewer incisions can be used, but whether patients gain a real, durable, and reproducible benefit without increased risk of leak, trocar-site hernia, GERD, or revisional surgery. Future evaluation should prioritize trocar-site hernia, GERD, patient-reported outcomes, and long-term weight loss rather than port number alone.

This work received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

This manuscript is a narrative/scoping review and did not involve human participants, animal experiments, or identifiable personal data.

No new datasets were generated or analyzed during the preparation of this review.

Zheng Zuo drafted and revised the manuscript. Jinjian Xiang supervised the work, reviewed the manuscript critically, and served as corresponding author. Both authors approved the final manuscript.