Comparison of efficacy and safety of the enhanced-view totally extraperitoneal (eTEP) and transabdominal (TARM) minimal access techniques for retromuscular placement of prosthesis in the treatment of irreducible midline ventral hernia.

BACKGROUND: Retromuscular plane for mesh placement is preferred for ventral hernia repair. With the evolution of minimal access surgeries, newer techniques to deploy a mesh in the sublay plane have evolved. We compared two such minimally invasive approaches for repair of irreducible ventral midline hernia with respect to the efficacy and safety of the procedures. PATIENTS AND METHODS: This is a retrospective study of a prospectively maintained database of 73 patients operated with retromuscular placement of mesh for irreducible ventral midline hernia by enhanced-view totally extraperitoneal (eTEP) or transabdominal retromuscular (TARM) repair. We recorded and compared the intraoperative and post-operative complications, post-operative pain score, recovery, recurrence, subjective technical ease of procedure and patient satisfaction after 3 months and 12 months of the surgery. RESULTS AND
CONCLUSION: Thirty-eight patients were operated by eTEP technique and the subsequent 35 were operated by TARM repair. There was no significant difference in the outcome of surgery and complications by the two techniques. However, there was a significant subjective technical ease in the TARM group due to ergonomic triangulated port placement and adhesiolysis and reduction of hernia contents under vision. The number of ports used and post-operative pain were, however, higher in the TARM group as compared to that of the eTEP group. Nearly 96% of the patients belonging to both groups were satisfied with their surgery after a year on telephonic follow-up. However, further studies and follow-up of patients would be required to establish the advantage of one technique over the other.

INTRODUCTION

Several laparoscopic and robotic techniques have been introduced for hernia repair in this era of minimal access surgery, allowing wider dissection, faster recovery, better cosmesis and often better outcomes. Ventral hernia repairs for fascial defects more than 2 cm in size are reinforced with placement of prosthesis. The mesh can be placed in different planes as onlay, inlay, sublay or underlay.[1] Retromuscular or the sublay repair has been advocated to follow the physiological principles for reinforcement.[2] By avoiding the contact of the mesh with the bowel and skin, this technique also minimises complications such as adhesions, fistula formation and mesh infection.[3]

We compared two such methods of minimally invasive ventral hernia repair – Enhanced-view totally extraperitoneal (eTEP) and transabdominal retromuscular repair (TARM) – for irreducible midline ventral hernia.

PATIENTS AND METHODS

A retrospective comparative study of a prospectively maintained database was conducted after obtaining ethics committee approval, at a tertiary care centre. All patients operated by the principal investigator between November 2017 and February 2020 with laparoscopic retromuscular mesh placement for irreducible ventral hernia repair (primary and incisional) with defect size ranging from 3 to 8 cm were included in the study. Patients having obstructed or strangulated hernia and requiring bowel resection for the primary pathology were excluded from the study.

The initial 38 patients were offered eTEP repair (Group A). With the introduction of TARM repair, the subsequent 35 irreducible ventral hernias were treated with this procedure (Group B). Patients ranged from 36 to 59 years in age with a male: female ratio of 27:46. The demographic pre-operative details, operative details including number of ports used; the defect size, location and number as per the European Hernia Society classification of abdominal wall hernias; content of the hernia sac; blood loss; operative time; surgeon’s subjective feasibility of the surgery; intraoperative complications including major bleeding and trauma to the bowel and other abdominal organs; conversion to open surgery; requirement of posterior-component separation and difficulties; post-operative pain scoring by visual analogue scale (VAS); day of removal of drain; post-operative day of starting soft diet; duration of hospital stay; post-operative complications including paralytic ileus, seroma formation and surgical-site infection (SSI); recurrence till the time patient was admitted and patient satisfaction in terms of pain, recurrence and subjective sense of well-being on telephonic follow-up at 3 and 12 months were recorded. All patients were operated under general anaesthesia with a nasogastric tube and urinary catheter in place.

Operative procedure

Extended-view totally extraperitoneal (eTEP) repair technique

With the patient placed in a supine position under general anaesthesia, a 10-mm port was placed by the open method in the epigastrium to the left of the midline in the retrorectus space. With a 0° telescope, the left retrorectus space was dissected, enabling the insertion of two working ports in the left retrorectus space under vision, medial to the linea semilunaris [Figure 1]. Blunt dissection was continued up to the cave of Retzius aided by carbon dioxide insufflation. As originally described by Daes, crossover to the right side was achieved in the epigastrium anterior to the falciform ligament, avoiding damage to the linea alba.[4] Port 4 was placed high up in the right retrorectus area and the space was dissected craniocaudally. The left and right spaces were then also connected in the infraumbilical region. The hernia was identified, and the peritoneum was opened proximal to the sac to avoid injury to the contents that may have been adherent to the sac. Intra-abdominal contents were inspected to ensure complete reduction and to detect injury, if any. Infraumbilical crossover was done to open up the space of Retzius. The peritoneum on the both sides of the defect was pulled medially to assess tensionless closure; if not, posterior-component separation was done and noted. The defect in the anterior sheath was sutured with intracorporeal suturing with no. 1 polydioxanone (PDS) barbed suture, following which the posterior rectus sheath was sutured with an absorbable 2.0 PDS. The dimensions of the retrorectus space were measured and an appropriately sized polypropylene mesh was placed. Drains were placed if required and space was allowed to desufflate gradually. The port sites were closed, and external compression was provided to the defect area.

Figure 1

(a) Port placement in eTEP repair, (b and c) retrorectus space created on both sides and connected in the midline with intact linea alba up to the hernia defect, (d) defect in the anterior and posterior rectus sheath after reduction of hernia content, (e) vertical closure of posterior rectus sheath, (f) placement and fixation of mesh

Transabdominal retromuscular repair technique

In this technique, the patient was placed in a supine position with legs split after anaesthesia, the surgeon stood between the legs and the monitor was kept at the head end. The peritoneum was entered just cranial to the pubic bone with two working ports in the midclavicular line on either side [Figure 2]. Adhesiolysis and reduction of hernia contents was performed under vision. The posterior rectus sheath on both sides was cut transversely up to the linea semilunaris at the level of the defect and a retromuscular space was created on either side up to the subcostal margin, keeping the linea alba intact with a crossover. Three mirror ports were then placed in the epigastrium in the retromuscular plane. The surgeon moved to the cranial side and used another monitor placed at the foot end of the patient. The retromuscular space was created caudally on either side so as to reflect the bladder and expose the pubic bone. The infraumbilical ports were then withdrawn into the retromuscular plane. Posterior-component separation was done if required to have a tensionless closure of the peritoneum. The defect in the anterior sheath was sutured intracorporeally followed by repair of the posterior rectus sheath transversely from one end to the other, using delayed absorbable suture (PDS) for both. A polypropylene mesh was placed in the retromuscular plane. After confirming haemostasis, suction drains were placed, if required. Gas was desufflated, and the ports were closed with external compression to the defect area. In patients with an infraumbilical defect (M4), an attempt was made to raise only one flap from the cranial aspect using three ports only.

Figure 2

(a) Port placement in transabdominal retromuscular repair, (b) hernia defects after reduction of contents, (c) posterior rectus sheath cut transversely at the level of defect, (d) retrorectus space created on both sides and connected in the midline, maintaining intact linea alba, (e and f) posterior rectus sheath defect closed transversely

In both the procedures, care was taken to avoid damage to the laterally placed neurovascular bundles over the posterior rectus sheath near the linea semilunaris, and the superior and the inferior epigastric vessels were preserved to avoid denervation myopathy and bleeding. All patients received ultrasound-guided transversus abdominis plane block (TAP block) for analgesia.

The patients were started on oral sips after 6 h and gradually progressed to a soft diet with return of bowel sounds. All patients were given stool softeners and plenty of oral fluids once orals were tolerated. The drains placed were kept for 48 h as a protocol and removed once the 24-h drain output was <30 ml.

RESULTS

Nearly 84.6% of the patients in Group A (eTEP) had a primary ventral hernia, 7.7% had a history of prior emergency exploration and 7.7% had prior hernia repair. Almost 85.7% of the patients in Group B (TARM) had primary ventral hernia, 11.4% had a history of prior exploration and 2.9% had prior hernia repair [Table 1]. In Group A, 34 patients had a hernia located in the M3 region, whereas 4 patients had defects extending from M3 to 4. In Group B, 30 patients had a defect in the M3 region, whereas 5 patients had M3–4 defects. Five patients in Group A had multiple defects, which were measured as one defect to a size of 5–5.5 cm, whereas 4 patients in Group B had multiple defects with an average size of 5.2 cm.

Table 1

Clinical profile of the study groups and comparison of operative parameters

Parameters/group	Group A (eTEP repair)	Group B (TARM repair)
Age (years), mean±SD	48.97±7. 7	48.97±7. 7
Male/female (%)	30.8/69.2	40/60
Primary hernia (%)	84.6	85.7
Number of ports used	4 (+1)	6 (−3)
Duration of surgery (min)	100.97±20.56	100.06±16.89
Soft diet started on post-operative day, mean±SD	2.49±0.79	2.23±0.426
Discharge (post-operative day), mean±SD	4.69±0.95	5.11±0.05
Complication (%)	29	8.6

SD: Standard deviation, eTEP: Enhanced-view totally extraperitoneal, TARM: Transabdominal retromuscular

The port requirement in eTEP was 4 in 87.2% of the patients, whereas 12.8% required one additional port. In Group B, 85.7% of the patients required 6 ports, whereas 14.3% of the patients were operated with only three ports with one-flap technique.[5]

The eTEP group had 17.9% enterocoeles, 5.1% were incarcerated (omentum), 10.3% had large bowel with omentum and 66.7% had only omentum as hernia contents, whereas the TARM group had 14.3% enterocoeles, 5.7% were incarcerated (omentum), 5.7% had large bowel with omentum and 74.3% cases had only omentum. There were no conversions to open surgery in both groups. Two patients in Group A while three from Group B required additional limited posterior-component separation unilaterally to achieve tensionless closure of the peritoneum. The use of bipolar and ultracision device was 89.7% and 10.3%, respectively, in eTEP, whereas in TARM, it was 91.4% and 8.6%, respectively. The difference was not statistically significant. The mean duration of surgery in both the groups was 100 min.

Pain was scored by the patients on a VAS, and pain at all time points was statistically significantly lower in the eTEP versus TARM group (P < 0.05) [Figure 3]. Both the groups received non-steroidal anti-inflammatory drugs for analgesia. Neither group required prolonged post-operative ventilatory support or analgesic infusion. The intraoperative and post-operative complications noted were bleeding, paralytic ileus, bowel injury and SSI [Table 2]. In Group A, two patients had bowel injury in the form of serosal tear intraoperatively, which was repaired immediately; there were two cases of intraoperative haemorrhage while reducing the omentum, which was managed with bipolar diathermy, while seven patients developed paralytic ileus, which recovered with conservative management. Group B had no patients with bowel or omental injury. However, this difference noted between the two groups was not statistically significant. None of the patients in the two groups developed SSI or seroma. Closed drains were placed in nine patients in Group A and seven patients in Group B. The average hospital stay was 4.6 days in Group A and 4.3 days in Group B.

Figure 3

Comparison of mean post-operative pain scores (visual analogue scale)

Table 2

Comparison of complications associated with both the procedures

	Haemorrhage	Bowel injury	Paralytic ileus	SSI	Recurrence
eTEP (n=38)	2	2	7	0	0
TARM (n–35)	0	0	3	0	0

eTEP: Enhanced-view totally extraperitoneal, TARM: Transabdominal retromuscular, SSI: Surgical-site infection

On telephonic follow-up at 3- and 12-months post-surgery, 96% of the patients in both groups were satisfied with their surgery in terms of absence of pain and recurrence and a subjective sense of well-being with a smooth return to daily activities.

DISCUSSION

Laparoscopic intraperitoneal onlay mesh repair (IPOM) was one of the earliest minimally invasive procedures for ventral hernia repair described in 1990 by LeBlanc and Booth and was later improvised to IPOM plus.[67] Though a misnomer, the contents were reduced under vision and the defect was reinforced with a composite mesh placed below the peritoneum (underlay). However, complications such as bowel injury, adhesions, obstruction, mesh infections and enterocutaneous fistulae have been documented due to mesh–bowel contact.

Daes described a novel minimal access technique (eTEP) to dissect the retromuscular space and repair inguinal hernia laparoscopically with sublay mesh placement.[4] The eTEP repair was advocated for ventral hernia repair by Igor Belyansky et al. It is not only a more physiological reinforcement as compared to IPOM but also enables the placement of a large mesh from one linea semilunaris to another, from the epigastrium to the cave of Retzius, which can be extended further laterally, if required.[8] eTEP reduced the cost of the mesh (polypropylene vs. composite mesh) and also did not allow it to come in contact with the intestines, minimising complications such as adhesion formation and enterocutaneous fistula. Furthermore, it allowed restoration or plication of the linea alba. However, it required the surgeon to be well versed with advanced laparoscopy and intracorporeal suturing with a thorough understanding of the anatomy of the abdominal wall. Furthermore, being an essentially blind procedure, it necessitated that the peritoneum be opened away from the defect so that injury to the hernia contents could be avoided during reduction, especially in the case of irreducible hernias. This, however, could cause a larger defect in the posterior sheath and thus lead to difficulty in re-approximation. In our case series, when the defect in the posterior sheath was wide, the inferior flap was pulled up to have a tensionless horizontal suture line. If achieving a tensionless closure was found difficult, transversus abdominis release was performed. All the patients in the TARM group had a horizontal closure of the posterior rectus sheath facilitating the ease of closure, while about 12% of the patients in the eTEP group had to be sutured horizontally.

Diagnostic laparoscopy and adhesiolysis with reduction of the contents followed by repair of the ventral hernia by eTEP has been suggested for irreducible hernias.[9] In our opinion, this may be implemented earlier in the learning curve of laparoscopic ventral hernia repair.

TARM repair, introduced by Masurkar, is a transperitoneal low-cost procedure that could be performed with conventional instruments with an ergonomic triangulation of the ports, making intracorporeal suturing more convenient.[10] In the present study, contents of the sac were inspected intraperitoneally and reduced under vision, thus reducing the probability of bowel injury. The working space was wider than the retrorectus space, allowing better vision, dissection and suturing. However, this technique required an additional set of ports to create the same space on the opposite side.

Posterior sheath rupture though rare has been documented following eTEP. The aetiology is attributed to repair of the PRS under tension.[1112] In our series, we had no patient with rupture of the posterior rectus sheath repair in any group. Various methods such as pulling up the inferior loose flap to suture the defect horizontally or adding transverse abdominis release have been suggested. We postulate that a horizontal closure of the posterior rectus sheath may be stronger and tensionless, which is routinely performed in TARM, which would decrease the chances of this complication. This may be attributed to the horizontal orientation of aponeurotic fibres in the posterior rectus sheath, which is thus better approximated horizontally than vertically.[1314] This theory, however, will require further study and analysis to confirm.

As per our literature search, this is the first study of evaluation of laparoscopic procedures for retrorectus repair of ventral hernia. For irreducible ventral hernia, TARM appeared to be safer than eTEP as the reduction of hernia contents was under vision, which was further aided by ergonomic port placement and wider working space, allowing ease in adhesiolysis. There was no significant disparity in the duration of surgery between the two groups. Laparoscopic TARM was found to be effective for repairing small- and medium-sized irreducible ventral hernias. Myo-fascial medialisation for tension-free closure, if needed, could be achieved via posterior component separation-transversus abdominis release with the same ports. With outcomes comparable with eTEP, these results support further evaluation of the technique in a large multicentric trial.

CONCLUSION

The comparison between eTEP and TARM groups of comparable demographic profile concluded that TARM is better in terms of reduced surgical complications and ease of performance by the surgeon. The post-operative pain scores, however, in TARM, were higher than eTEP.

eTEP is a well-accepted and widely practiced procedure for ventral hernia repair. However, when performed for irreducible hernia, it may entail difficulty in reduction, especially if there are sac-content adhesions. TARM allows reduction of the contents under vision, with the dissection and placement of prosthesis being in the same plane as that of eTEP. The advantage of one procedure over the other is still a matter of debate and requires large-scale trials to obtain a definite result. We recommend a patient-tailored approach based on patient characteristics, nature of hernia and the surgeon’s ability and limitations.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.