Ventral abdominal wall hernia has an estimated prevalence of 5% in the general population [1] and is increasingly prevalent due to an aging and increasingly obese society, receiving more abdominal surgery [2]. The Rives Stoppa procedure is a proven efficacious treatment for ventral abdominal wall hernia and the retrorectus mesh placement may be considered most favorable [3, 4]. In 2022, a systemic review showed superior outcomes compared to other techniques. However, surgical site infection was less prevalent in intraperitoneal onlay mesh (IPOM) repair, clearly benefitting from the minimally invasive approach [3]. The IPOM technique was a first attempt at minimally invasive hernia repair, seeking benefits of less extensive dissection in the subcutaneous tissue, shorter hospital stays, and fewer surgical site infections. However, complications such as recurrences, bulging, formation of intraperitoneal adhesions, fistulas, and bowel damage are known complications of IPOM repair [5, 6].

Combining the benefits of a minimally invasive (laparoscopic) approach and retromuscular mesh position, Schroeder et al. described a laparoscopic transabdominal technique: the Trans Abdominal Retrorectus Umbilical Prosthesis (TARUP). Authors concluded that the new approach was a safe and effective alternative to open Rives Stoppa, but also a technically demanding procedure [4]. In 2018, Muysoms et al. reported on the robotically assisted TARUP procedure (rTARUP). This adaptation of Schroeder’s laparoscopic approach showed similar complication rates and shorter operative times [7].

Since 2018, only a handful of reports on rTARUP (or now also known as rTARM, Trans Abdominal Retromuscular Mesh) has been published, with limited number of patients and limited follow up. Garza et al. reported on a 101 patient series with 3 years follow-up showing low recurrence rates of 3% and improvement in quality of life according to the EuraHS Quality-of-Life scale [8]. Vierstraete et al. reported a similar recurrence rate of 3.7% at a median follow up of 4.5 years of 162 patients, with a complication rate of 6.2% [9].

We believe rTARUP/rTARM may be considered an important improvement in the treatment of ventral abdominal wall hernias. This study reports on technical aspects, short and long-term outcomes and quality of life of rTARUP. In addition, we comment on lessons learned since the implementation of rTARUP in two teaching hospitals in the Netherlands.

This study shows that rTARUP is a safe and effective procedure. Recurrence rate was low at 2 years follow-up. A large majority of patients reported a better or much better quality of life after surgery.

Literature about rTARUP outcomes is scarce and mostly describes short-term follow-up. Follow-up studies of respectively 30 days and 6 weeks were reported by Ferraro et al. (81 patients) and by Baur et al. (30 patients) with no recurrences reported in either study [22, 23]. In the current study, a recurrence rate of 2.4% is found at a median follow-up of 24 months. Because we scheduled in-office visits at 2-year follow up on indication, it is possible that we underestimate the true rate of recurrence in our study, asymptomatic or subclinical recurrences may not have been detected. Our rate is comparable with other long term follow-up studies, describing recurrence rates varying between 1.48%–3.96% after 12–36 months of follow-up [8, 24, 25]. The longest series currently described follows 162 patients for 4.5 years with a recurrence rate of 3.7% [9]. Their method was of follow up was comparable to ours and consisted of telephonic follow up with additional in-office appointments on indication. Because they report on a follow up time that is twice ours, it is reasonable to assume our recurrence rate will also increase with time. It is important to note that two of our recurrences occurred cranially from the mesh where the rectus diastasis was not completely approximated. Possibly they were missed small epigastric hernias that progressed to clinical hernias. Diastasis recti recurrence occurred in two patients, who both had a BMI above 30.

Comparable recurrence rates are seen for rTARUP compared to open Rives-Stoppa. In a large meta-analysis by Den Hartog et al., consisting of 93 studies representing 12,440 patients, the recurrence rate after retro-rectus repair according to Rives-Stoppa was 3.2% at 12 months and 4.1% at 24 months. Den Hartog et al. also included studies in which recurrent hernias were treated, reporting a recurrence rate of 3.7% at 12 months for this subgroup [3]. For our study population, the recurrence rate in this subgroup was 5.4% at 24 months follow up.

Because rTARUP can create damage or weakness to the lateral border of the rectus sheath, some surgeons prefer eTEP to avoid a lateral incision. rTARUP/rTARM was decribed earlier than eTEP and eTEP can be seen as a logical next step after rTARUP in the development of robotic AWS. A possible disadvantage of eTEP is that it is even more technically challenging and that intra-peritoneal adhesions may be missed. We believe both techniques deserve a place in minimally invasive ventral hernia surgery. In a systematic review and meta-analysis by Brucchi et al., rTARUP was compared with Robot-assisted Enhanced-view Totally Extraperitoneal (r-eTEP). Three studies, representing 308 patients (r-eTEP 176, r-TARUP 132) were included for analysis [26]. There were no recurrences in either group reported at 35 months of follow up in the study by Olivier et al. [27]. The two other included studies also reported zero recurrences, at a maximum of 90 days follow-up [28, 29]. In the systematic review by Brucchi et al., comparing r-eTEP to rTARUP, no significant differences were found regarding major complications, recurrence or 30-day readmission. Minor complications occurred significantly more often in the rTARUP-group with a risk difference −0.14 for r-eTEP. However, because rTARUP was performed earlier in the learning curve and extensive adhesiolysis was required in 43.9% of patients, the authors suggest this perceived risk difference might be study-specific rather than an inherent advantage of the r-eTEP technique [26]. Brucchi et al. concludes that current evidence remains insufficient to favor one approach over the other, and more data is required to guide surgical decision making.

In the current study, we report a 30-day complication rate of 7.2%, including three (2.4%) major complications requiring a re-intervention. Complication rates were again highest in the recurrent hernia subgroup, with a rate of 16.2%. Lack of data from other studies makes it difficult to put these results in perspective. However, the results underline the complexity of treatment of this specific subgroup. To the best of our knowledge, no other studies regarding rTARUP outcomes have included recurrent hernias. In the primary hernia group complication rates were low (1.6%). These results are more favourable compared to other studies. Garza et al. reported surgical site complications requiring procedural intervention in 5% of patients, in which one hematoma was evacuated from the retromuscular space, and one seroma was drained. Other complications consisted of subcutaneous seromas/hematomas and a wound infection [8]. Muysoms et al. described patients (4.9%) needing surgical re-intervention due to one retromuscular hematoma and one superficial skin infection [7]. The study group published follow up data in an abstract-only paper, in which they report six (3%) readmissions within 30 days [24]. Baur et al. report a minor complication rate of 30%, and 6.7% of patients had major complications [23]. Because diastasis recti was present in 95% of our patient population, it is interesting to compare our data to the results of Cuccurullo et al. who studied 45 patients with ventral hernia and concomitant rectus diastasis. Their study population consisted of three-quarters primary hernia and one-quarter incisional hernia and were treated with rTARUP. No major complications were reported [25]. Ferraro et al. report a complication rate of 7.4%, comparable to our results [22].

This study shows that rTARUP can be safely performed in outpatient setting and can be performed in a timely manner with a median operative time of 134 min and a median surgical (skin to skin) time of 90 min. In the meta-analysis by Brucchi et al., operative times were 176 and 178 min for r-TEP and r-TARUP, respectively [26]. Operative times improved significantly over time. The difference in operative times between centers can be explained by differing levels of prior robotic experience between surgeons. Per protocol, RdGG patients were not operated as daycase. This was due to patients receiving intrathecal morphine and consequentially, a urinary catheter. At OLVG, the anesthesia protocol included general anesthesia without epidural or intrathecal pain administration and allowed for same day discharge.

We also address the importance of quality-of-life outcomes in our study, as opposed to only reporting on surgical outcomes. A methodical limitation of our study is that we only collected post-operative quality-of-life data and cannot compare the pre-operative quality of life. Of the entire study group, patients with incisional hernias had the best EuraHS-quality of life scores, with a total score of 6.66/90. Primary hernias were second with a median score of 9/90, and recurrent hernias were last with 10/90. Quality of life data after rTARUP is limited. Cuccurullo et al. described an improvement in mean total EuraHS-QoL score from 60/90 pre-operatively to 16/90 post-operatively. In the total domain scores, there was barely any pain or feeling of restriction in any of the subgroups. The cosmetic domain did least well with score of 4/20 or 5/20 in all subgroups. An important complaint was a postoperative central bulging of the midline closure. Therefore, it is important to properly council patients about the way the surgery affects the abdominal wall and that it does not treat any excess skin that has developed with the hernia. Further research is warranted into risk factors for cosmetic dissatisfaction and to determine the best treatment for ventral hernia patients with concomitant rectus diastasis, who are often young (post-partum) women in which cosmetic results may be of more importance.

Despite the favourable median pain scores, six patients (4.8%) reported experiencing chronic pain during follow up. Two patients were diagnosed with painful scar tissue. These patients stated the pain was manageable and were comforted with the knowledge it was not caused by recurrence. In four patients reporting chronic pain, prior investigations have ruled out conditions such as recurrence, mesh infection or other complications. The cause of pain in these cases remains unclear, which warrants further research into its origin. Known risk factors for the development of chronic pain after ventral hernia repair include acute pain before surgery, poorly managed pain in the direct post-operative period, and pain at 1-month post-surgery, as well as recurrent hernia, female sex and younger age [30, 31]. Clearly, it is important to ensure adequate pain management in the peri-operative period. Literature about chronic pain after minimally invasive retromuscular hernia repair is scarce. Krpata et al. studied the effect of medium-weight versus heavy-weight polypropylene mesh after open ventral hernia repair in a randomized controlled trial of 350 patients. At 30 days and at 1 year follow up, pain scores were identical in both groups, as well as other quality of life outcomes [32]. Post-herniorrhaphy chronic pain in inguinal hernia has been studied extensively, and estimations are that 8%–16% of annually performed groin hernia repair result in chronic pain that impairs daily lives for 6 months postoperatively [33]. Laparoscopic techniques seem to cause less pain than open techniques, as well as non-mesh-based techniques in dedicated centers. When heavyweight meshes were compared with lightweight meshes in laparoscopic groin hernia repair, results were comparable [33]. In groin hernia repair, chronic pain can be multifactorial, and it is often hard to make a definite diagnosis of the cause of the pain. Perioperative injury to nerves could lead to pain, as well as entrapment of nerves in a meshoma or in shrinkage of a mesh. Another way for mesh to cause pain could be by the inflammatory response to the mesh [33]. It is likely those same mechanisms are contributing to pain after minimally invasive ventral hernia repair, but more research is needed to determine contributors to chronic pain in this specific patient group.

This study has its limitations. Firstly, a retrospective analysis of consecutively collected series was performed, which brings risk in terms of bias. Secondly, we cannot compare the quality of life pre- and post-operatively due to the missing pre-operative quality-of-life data. During prospective follow up, we could not reach all patients. Our response rate of 77.6% is acceptable, but it could potentially over- or underestimate our quality-of-life outcomes. Lastly, all surgeries were performed by experienced hernia surgeons, which limits the applicability of our results to surgeons with similar levels of experience.

Strengths of this study were the long follow up period and the multicentered character of the study, broadening generalizability. Because the study was conducted at top-clinical ventral hernia repair centers, we were willing to treat and include patients undergoing repair for recurrent hernias or patients with extensive abdominal history. This shows the applicability of this procedure in a wide group of hernia patients. We also gathered quality of life data during follow up, which adds to the patient perspective of this new technique and provides us with ways on how to further improve the operation itself and the post-operative period. Both surgeons have broadened techniques for this category of patients to rTAPP and eTEP in certain indications although rTARUP is deemed the default operation, especially in the beginning of learning curves.

Economical costs and benefits were outside the scope of this study but are important to address. The robotic approach could be more economically favourable when considering the decreased length of hospital stay, the low complication and recurrence rates, and that patients are generally able to return to work sooner as compared to other, open techniques. More research is needed to determine costs and benefits and to be able to economically justify robotic surgery in abdominal wall repairs and [22, 35].

This study about rTARUP/rTARM shows encouraging results regarding safety and efficacy. With experience, rTARUP can be carried out in a timely manner and performed in day care. Because potential short hospital stay and operative times, rTARUP could eventually be more cost-effective than open approaches in the treatment of ventral hernia. The study also demonstrates the safe and efficacious use of rTARUP in patients with recurrent hernias. Although perioperative complications occur more often in this group, recurrence rates were low, indicating that rTARUP might offer a solution for this complex patient population. More research is warranted into the development of long-term complications such as chronic pain after minimally invasive ventral hernia repair and into economical costs and benefits. Another opportunity for research is to determine best treatment options for ventral hernia patients with concomitant rectus diastasis and risk factors for cosmetic dissatisfaction.