This retrospective study enrolled 58 patients who underwent surgery using the L-SILTEP approach for inguinal hernia repair between June 2021 and April 2023. All procedures were performed by skilled surgeons using a 10 × 15 cm lightweight polypropylene mesh without fixation. The study included patients from three hernia centers: Shanghai General Hospital, Shanghai (n = 16); Affiliated Hospital of the Medical School of Ningbo University, Ningbo (n = 34); and Fudan University Pudong Medical Center, Shanghai (n = 8). Informed consent was obtained from all participants. The study protocol was reviewed and approved by the ethics committees of the three hospitals, with approval numbers 2020-053, XJS20191206, and 2020PWR-03 respectively.

Data on patient characteristics, including age, sex, body mass index, American Society of Anesthesiologists (ASA) classification score, and hernia features, were collected. Perioperative data included incision length, surgical duration, blood loss volume, and incidence rates of peritoneal rupture and complications (e.g., vascular, vas deferens, bowel, and bladder injury). Postoperative data included pain scores assessed using the visual analog scale, incidence rates of complications (e.g., surgical site infection, mesh infection, seroma, hematoma, and scrotal edema), length of hospital stay, incisional hernia rate, and recurrence rate.

The standardized preoperative workup of patients began with a detailed history and physical examination. The inclusion criteria were as follows: (1) patients with unilateral inguinal hernia who consented to L-SILTEP, (2) those aged 18–80 years, (3) and those with preoperative ASA grade 1 or 2, with a preference for patients with a history of middle and lower abdominal surgery. The exclusion criteria were as follows: (1) patients with acute incarcerated hernia, (2) those with a body mass index of > 30 kg/m2, (3) those with cardiopulmonary complications preventing tolerance of general anesthesia and surgery, and (4) those with surgical scar or skin infection near the McBurney point or the anti-McBurney point.

After the induction of general anesthesia, the patient was placed in the Trendelenburg position at a 15° head-down tilt, and the operating table was tilted 15° to the healthy side. The chief surgeon stood on the same side as the hernia, with the first assistant positioned behind the chief surgeon next to the patient’s shoulder. Urinary catheterization was routinely performed. The pneumoperitoneum pressure was set to 12 mmHg, and the pneumoperitoneum flow rate was set at 20 L/min.

The six-step L-SILTEP approach is as follows:

Step 1: Incision selection and device placement

Access was gained via a 2–2.2-cm transverse incision made 1–2 cm above the McBurney point or the anti-McBurney point (Fig. 1a). Subsequently, the aponeurosis of the external oblique abdominal muscle was cut anterogradely, and the internal oblique and transverse abdominal muscles were separated by pulling perpendicular to the muscle fibers to expose the extraperitoneal fat. After enlarging the preperitoneal space with the index finger, the port was inserted to establish the operative space (Fig. 1b).

L-SILTEP procedure. a Selection of incision location and b placement of port. c Freeing the extraperitoneal space above the internal ring. d and e: Exposure of the Bogros space and internal ring. f Exposure of the Retzius space. g and h Separation of dense adhesions. i Closure of the peritoneum by continuous suturing. j Dissection of the hernia sac. k Exposure of the entire myopetinal orifice. l Placement of the mesh

Step 2: Establishment of the preperitoneal space

Establishment of the preperitoneal space involved freeing the extraperitoneal space above the internal ring (Fig. 1c), followed by exposing the inner ring and expanding into the Bogros space, guided by the peritoneum (Fig. 1d, e). Subsequently, medial turning and dissection into the Retzius space were performed until reaching the pubic symphysis and crossing the midline (Fig. 1f). In cases of dense adhesions from previous surgeries, careful separation close to the abdominal wall was necessary (Fig. 1g, h). If required, the peritoneum was actively incised and extended inward across the adhesive area, followed by closure with a running suture (Fig. 1i). The space was then expanded from bottom to top, up to 8 cm above the pubic symphysis and 2–3 cm below the Cooper’s ligament.

Step 3: Hernia sac dissection

Using an indirect hernia as an example, the outer and posterior parts of the hernia sac were initially dissociated from the spermatic cord, guided by the peritoneum. Subsequently, the hernia sac was laterally pulled to dissociate the anteromedial part. The technical approach to hernia sac dissection emphasized starting laterally and maintaining a peritoneal orientation (Fig. 1j). In cases where the sac was excessive or densely adherent, it was ligated and transected below the inner ring to avoid damaging the spermatic cord structures. In female patients, the ligamentum teres uteri was preserved by longitudinally cutting the hernia sac below the inner ring, ensuring a distance of > 5 cm from it. Finally, the peritoneum was closed using a running suture with barbed sutures.

Step 4: Parietalization of the spermatic cord and space expansion

The hernia sac and peritoneum were completely detached from the cord, a process known as parietalization. The Bogros space was further extended along the medial surface of the iliopubic tract to the position of the anterior superior iliac spine. Following dissection, the entire myopetinal orifice was cleared of peritoneal and fatty tissues (Fig. 1k).

Step 5: Mesh placement and preperitoneal deflation under vision

For hernia repair, either the 3DMax lightweight mesh in a large size (Bard) or the lightweight mesh (Johnson & Johnson UMF) was used. The mesh was inserted through the port and expanded around the hernia ring to completely cover the myopetinal orifice. Subsequently, the lower edge of the mesh was secured with a clamp to prevent displacement during preperitoneal deflation (Fig. 1l).

Step 6: Removal of the port and closure of the incision

The port was removed, and the fascia of the internal oblique muscle was sutured. Subsequently, the incised external oblique aponeurosis was sutured continuously. Finally, the skin incision was closed with an absorbable suture.

Quality of life and cosmetic satisfaction assessments were conducted either in person, via telephone, or through electronic communication between the clinical team and patients who consented to participate in the study and data collection. Quality of life was evaluated using the Carolina Comfort Scale (CCS), a validated hernia-specific questionnaire with a rating scale of 0–5 (0 indicating “no symptoms” and 5 indicating “disabling symptoms”), assessing pain, mesh sensation, and movement limitation. Cosmetic satisfaction was assessed using the Score of Access-Site Satisfaction & Consideration questionnaire, where satisfaction levels were rated on a scale of 1–10: 1 for extreme dissatisfaction, 5 for neutral satisfaction, and 10 for extreme satisfaction [14].

Data analysis was performed using Statistical Package for the Social Sciences software version 22.0 (IBM Corporation, Armonk, NY, USA). Qualitative data are expressed as percentages, whereas quantitative data are expressed as mean ± standard deviation or median (min–max) depending on their distribution. Statistical comparisons between groups were conducted using the Wilcoxon rank-sum test for quantitative variables and Pearson’s chi-square test for categorical variables. A P value of < 0.05 was considered statistically significant.