Vol.:(0123456789)1 3

Hernia (2018) 22:837–847 https://doi.org/10.1007/s10029-018-1795-z

HOW-I-DO-IT

Early operative outcomes of endoscopic (eTEP access) robotic-assisted retromuscular abdominal wall hernia repair

I. Belyansky1 · H. Reza Zahiri1 · Z. Sanford1 · A. S. Weltz1 · A. Park1,2

Received: 17 November 2017 / Accepted: 22 June 2018 / Published online: 4 July 2018 © Springer-Verlag France SAS, part of Springer Nature 2018

AbstractBackground The enhanced-view totally extraperitoneal (eTEP) hernia repair technique was first described for laparoscopic inguinal hernia repair and later applied to laparoscopic ventral and incisional hernia repair. We present our center’s early operative outcomes utilizing principles of this technique during robotic ventral and incisional hernia repair for implementa-tion of the robotic eTEP Rives–Stoppa (eRS) and eTEP transversus abdominis release (eTAR) techniques.Methods A review of a prospectively maintained database of hernia patients was conducted identifying 37 patients who underwent robotic eTEP for ventral, incisional, flank or parastomal hernia repair between March and October 2017. All patients underwent retrorectus dissection with selective utilization of transversus abdominis release (TAR) as indicated.Results 37 patients including 13 male and 24 female with mean age, body mass index, and ASA score of 54, 35.5, and 2.4, respectively, underwent a mean operation room time of 198 min. Mean length of stay was 0.7 days. There were no intraopera-tive complications. Two patients developed subcutaneous seromas requiring interventional radiology drainage. One patient was readmitted at 30 days for PO intolerance that was managed expectantly. Mean postoperative follow-up visit occurred at 36 days with no sign of early hernia recurrences.Conclusion The enhanced-view totally extraperitoneal approach is both safe and feasible in robotic-assisted repair of ventral and incisional hernias. Although long-term outcomes and patient selection criteria require further study, we believe this technique will become an important tool in the armamentarium of minimally invasive hernia surgeons.

Keywords Hernia · Ventral hernia · Incisional hernia · Robotic hernia surgery · Extended-view totally extraperitoneal · eTEP · eRS · eTAR  · AWR  · Abdominal wall reconstruction

Introduction

Rapid advancements in the field of minimally invasive ventral hernia repair have been recently made. Alternative trocar placements and a novel technique to remain in the extraperitoneal space during laparoscopic ventral incisional hernia repair have previously been described by our group

[1]. Nevertheless, the laparoscopic extraperitoneal approach continues to pose limitations in available degrees of free-dom and significant ergonomic challenges to the operating surgeon while requiring extensive technical and minimally invasive surgical expertise for proper execution.

Expert opinion and preliminary data support the asser-tion that robotically assisted surgical procedures provide increased degrees of freedom, may improve ergonomics, and allow scaling and performance of finer movements deemed difficult through alternate surgical approaches [2–4]. These advantages, in turn, may benefit both patients and surgeons. Specifically, they may expand the inclusion criteria to extend minimally invasive options to more anatomically challeng-ing patients while protecting surgeons from the fatigue and strain associated with implementation of such techniques [5, 6].

At our hernia program, we have employed the regular use of robotics to expand the application of minimally invasive

Electronic supplementary material The online version of this article (https ://doi.org/10.1007/s1002 9-018-1795-z) contains supplementary material, which is available to authorized users.

* I. Belyansky ibelyansky@aahs.org

1 Department of Surgery, Anne Arundel Medical Center, 2000 Medical Parkway, Suite 100, Annapolis, MD 21401, USA

2 Johns Hopkins University School of Medicine, Baltimore, MD, USA

http://crossmark.crossref.org/dialog/?doi=10.1007/s10029-018-1795-z&domain=pdfhttps://doi.org/10.1007/s10029-018-1795-z

838 Hernia (2018) 22:837–847

1 3

surgery to hernia disease. In March 2017, we began utilizing a robotic platform in the extraperitoneal space to address ventral and incisional defects of the abdominal wall. The aim of this study is to outline the operative steps of this novel robotic approach and to report our early operative outcomes.

The robotic extended‑view totally extraperitoneal (eTEP) access Rives–Stoppa technique

Popularized by Dr. Jorge Daes in 2012, the extended-view totally extraperitoneal (eTEP) technique enlarges the sur-gical field in comparison with the conventional TEP pro-cedure, allowing entry into the preperitoneal or retrorec-tus space from any portion of the anterior abdominal wall, while permitting additional room for dissection of more complex hernias. Using the aforementioned principles, the use of eTEP access was subsequently expanded to address ventral and incisional mesh-assisted hernia repairs in both the robotic eTEP Rives–Stoppa (eRS) and eTEP transversus abdominis release (eTAR) techniques [1].

Preoperative considerations

All robotic surgery candidates underwent standard history, physical examination, and basic laboratory testing to ensure they were appropriate candidates for major surgery. An up-to-date computed tomography (CT) study of the abdo-men and pelvis is recommended for effective preoperative planning, as is a recent screening colonoscopy for patients over the age of 50 years. On the initial encounter, all major comorbidities must be addressed by means of a multidisci-plinary approach before proceeding to the operating room. Diabetic patients must have their glycated hemoglobin levels managed to below 7.0%, and morbidly obese individuals must achieve a body mass index goal of less than 40 kg/m2. Patients with a smoking history must demonstrate cessation for at least 4 weeks before surgical intervention. Nicotine levels are assessed in the preoperative area on the day of surgery, and the case proceeds only if the patient’s test is negative. Any patient with active infection should be treated with properly selected antimicrobial therapy until resolu-tion of the infection before implantation of synthetic mesh compounds.

Access and port placement

The patient is positioned supine with arms tucked to the sides. After Foley insertion, sterile prep, and drape, the bed is flexed in a manner so as to open the space between

the subcostal margin and iliac crest as well as lower the legs in reverse Trendelenburg position to reduce collisions between the patient and robotic arms (Fig. 1). Relevant anatomy is marked, including the xiphoid process, bilat-eral subcostal margins, symphysis pubis, iliac crests, linea alba and semilunar lines.

In the robotic eTEP technique, the initial retrorectus dissection is performed via standard laparoscopy. Dynamic port placement based on the area of interest, previously described by our group, is perhaps the most important concept to understand for performing a successful eTEP access dissection [1]. The resulting case-dependent vari-ability in potential port placement allows for entry along the upper midline, lower midline, and lateral abdomen as dictated by location of the hernia defect. The retromus-cular space is insufflated to 15 mmHg. Once all ports are positioned, the robot is docked, and the robotic portion of the procedure begins.

A 5-mm skin incision is made in the area overlying the anterior rectus sheath. This area was marked previously and extends from the right linea semilunaris to the left linea semilunaris (Fig. 2a). A 5-mm laparoscopic camera is inserted into a 5-mm optical trocar connected to carbon dioxide (CO2) insufflation on high flow. Slow advancement of the trocar perpendicular to the surface allows visualiza-tion of the anterior rectus sheath, followed by the fibers of the rectus abdominis muscle. Once the muscle fibers are visualized, the direction of port advancement is angled so that the tip of the port is traveling almost parallel to the muscle fibers and superficial to the posterior rectus sheath, a white glistening layer. Insufflation of CO2 and blunt dis-section with a camera then allow development of the ret-rorectus space between the underside of the rectus muscle and the posterior rectus sheath (Online Resource 1A–D).

Fig. 1 Patient positioning

839Hernia (2018) 22:837–847

1 3

Relevant anatomy and the principles of crossover

The extension of the retrorectus domain into the preperito-neal space affords the surgeon generous room to strategically position working ports and dissect widely to ensure proper mesh overlap. The peritoneal layer incorporates contribu-tions primarily from the falciform and umbilical ligaments at the posterior aspect of the linea alba (Fig. 2b). The posterior rectus sheath receives contributing fascial fibers from the internal oblique and transversus abdominis muscles above the arcuate line and extends from the linea semilunaris bilat-erally with medial contributions to the linea alba (Fig. 2c). “Crossover” in the case of the eTEP technique refers to the surgical dissection that joins one retrorectus space to its con-tralateral counterpart without violating the intraabdominal cavity. This is accomplished by remaining superficial to the falciform and umbilical ligaments at the medial aspect of the abdominal wall, keeping the bridging peritoneal flap intact between the two edges of posterior rectus sheath, thus ensuring a continuous connection between the two retrorec-tus spaces laterally and the preperitoneal space medially. At the completion of the crossover, three spaces are con-nected: the left retrorectus space, the preperitoneal space, and the right retrorectus space. The developed dissection is limited only by the extent of the linea semilunaris bilaterally. Crossover should ideally be performed at a level of the mid-line which has not been previously violated. In instances of lower midline hernia defects, crossover should be attempted in the upper midline, with the reverse true for upper midline defects. A relative contraindication to crossover is history of previous midline incisions from xiphoid to pubis, as past violation of the preperitoneal space presents risk of bowel injury during this maneuver.

In brief, the steps of robotic eRS abdominal wall her-nia repair are as follows: once the retrorectus space is

completely developed and the hernia contents are reduced, defects in the anterior abdominal wall are primary closed with V-Loc™ absorbable 0 monofilament barbed sutures in running fashion. In addition, V-Loc™ absorbable 3–0 mono-filament barbed sutures are used to close any holes created in the posterior rectus sheath during its takedown. Finally, the developed retrorectus space is measured and a propor-tional macroporous medium-weight polypropylene mesh is cut and placed assuring complete coverage of the space and good overlap of hernia defect. When appropriate such as in patients with larger sized defects (> 8 cm), a noncom-pliant abdominal wall, narrow unilateral retrorectus space (< 6 cm), or tension on the posterior layer, TAR dissection is performed as previously described [2, 7–10].

Upper midline defects (lower dock setup)

When dealing with upper midline defects, we prefer to per-form the crossover below the level of the umbilicus, devel-oping the preperitoneal and retromuscular spaces that have not been previously violated. Figure 3a demonstrates the port position for upper midline defects. In this setup, we typically use four incisions. The first incision is made in the right upper quadrant (RUQ) in the region overlying the right rectus muscle. Applied Medical™ (Rancho Santa Margarita, CA) 5-mm ports were used for optical entry into the right retrorectus space, as outlined in Online Resource 1. Figure 4 demonstrates the typical sequence of port placement.

The first port (RUQ) is used as an assistant port later in the procedure. Special care should be taken to appreciate the right inferior epigastric vessels (Fig. 4a) which travel parallel and medial to the linea semilunaris. Next, under direct vision, a right lower quadrant (RLQ) port is placed just lateral to the inferior epigastric vessels and approxi-mately 3–4 cm below the horizontal line drawn through the

Fig. 2 a Labeling of relevant anatomical landmarks and b, c presentation of the preperitoneal and retrorectus spaces

840 Hernia (2018) 22:837–847

1 3

umbilicus (Fig. 4b). The RLQ port is further used to develop the space of Retzius with a blunt grasper. Once the space of Retzius is developed, a 12-mm bariatric length camera port is placed under direct vision in the lower midline, 3–4 cm below the umbilicus (Fig. 4c). A left lower quadrant (LLQ)

port is then placed, entering the space just lateral to the left inferior epigastric vessels (Fig. 4d).

The robot is then docked. A robotic 30-degree scope, in the up position, is used to start the dissection. Dissection proceeds with division of the medial contributions of the

Fig. 3 Port positioning for a upper midline defect repair (“Lower Docking”), b lower midline defect repair (“Upper Docking”), and c lateral defect repair (“Side Docking”)

Fig. 4 a–d Sequence of port placement in upper midline defect repair

841Hernia (2018) 22:837–847

1 3

posterior rectus sheath to the linea alba bilaterally from the caudal to cephalad direction (Fig. 5a).

At the medial aspect, we try to preserve the preperitoneal contributions to the posterior layer, which are made up of the falciform and umbilical ligaments. In such a fashion, the division of posterior rectus sheath and preservation of falciform ligament and umbilical ligaments allow us to join the right and left retrorectus spaces together with the midline preperitoneal space.

Following the dissection in these planes, we then antici-pate encountering the neck of the hernia sac (Fig. 5b, c). In a true incisional hernia, the layers surrounding the neck of the sac can be thoroughly fused and difficult to differentiate. A recent preoperative CT scan, therefore, is an invaluable aid for identifying the hernia and its contents. An attempt may be made in some cases to reduce the entirety of the sac by separating it from its distal attachments; however, we do not attempt this often. We frequently consider sharply opening the peritoneal layer just proximal to the neck of the sac to reduce the visceral contents under direct visualiza-tion, and perform limited adhesiolysis (Fig. 5d). Large distal sacs were often left in place and used to plicate the cavity with the fascial closure. Any defects in the posterior layer can be fixed with 2–0 or 3–0 absorbable suture (Fig. 6a, b). Once the hernia contents are reduced, we complete the release of the medial aspect of the posterior rectus sheath,

dissection concludes just below the level of the xiphoid pro-cess (Fig. 6c).

The linea alba is then reconstructed using 0 V-Loc™ (Medtronic) suture, medializing the healthy edges of rectus abdominis muscle to oppose each other. The hernia defect is closed as part of the linea alba reconstruction (Fig. 6d). The assistant at the bedside decreases the pneumoperitoneum to 10 mmHg or less as needed to offload tension during the closure, allowing for tightening of the sutures during defect closure. The suture is cut after taking 4–5 retrograde bites with the V-Loc™ suture over the previously run closure.

Relative contraindications to docking the robot inferior to the umbilicus for upper midline defects include history of Cesarean section, pelvic surgery, prostatectomy, or morbidly obese habitus with large pannus.

Lower midline defects (upper dock setup)

Figure 3b demonstrates the typical port approach for lower midline defects. Using the technique demonstrated in Online Resource 1, the first port is positioned in the uppermost aspect of the left upper quadrant (LUQ), just inferior and to the left of the subxiphoid region. The port enters the left retrorectus space, and, using the 5-mm laparoscopic camera, blunt dissection is performed to develop the space. An 8-mm

Fig. 5 a Robotic division of the posterior rectus sheaths, b, c visualization of the hernia, d adhesiolysis and reduction of the hernia

842 Hernia (2018) 22:837–847

1 3

robotic port and an assistant port are placed under direct vision into the developed retrorectus space (Online Resource 2A). The first Applied Medical™ port is then exchanged for a 12-mm bariatric length port, to be used as the robotic camera port. The 5-mm laparoscope is placed through the assistant port, thus visualizing the medial aspect of the left poste-rior rectus sheath in the upper midline. Because the upper midline has not been previously violated above the level of the umbilicus, the medial aspect of the left posterior rectus sheath is incised, and the preperitoneal space is entered just superficial to the falciform ligament. We prefer to perform these initial steps laparoscopically, using the hook monopo-lar instrument placed through an LUQ robotic port (Online Resource 2B). The right posterior rectus sheath is identified, and its medial aspect is incised and released in a cephalad to caudal direction, followed by blunt dissection in the right retrorectus space (Online Resource 2C).

An 8-mm robotic port is then placed in the RUQ under direct vision through the upper aspect of the right rectus abdominis muscle (Online Resource 2D). Once all the ports are in position, we then dock the robot. Robot-assisted ret-rorectus dissection is carried out in the caudal direction,

completing bilateral release of the posterior rectus sheaths (Online Resource 3). When encountering the hernia sac, we try to sharply dissect the distal attachments, thus mobilizing it downward. Alternatively, the sac can be sharply entered and adhesiolysis performed as needed. Steps and landmarks of dissection, as well as posterior layer closure and linea alba reconstruction, are identical to what has been described in the earlier section on upper midline defects.

Relative contraindications to docking the robot superior to the umbilicus for lower midline defects include history of upper midline surgeries, or past Kocher or Chevron sub-costal incisions.

Lateral dock setup

An alternative lateral, direct retrorectus docking approach is possible, port setup is demonstrated in Fig. 3c. This is perhaps currently becoming the most common approach we use with robotic platform, but the ability to reproduce this approach on a consistent basis depends on the width of the retrorectus space and the patient’s surgical history.

Fig. 6 a, b Residual hernia defect of the posterior layer, c retromuscular dissection, d reconstruction of the linea alba

843Hernia (2018) 22:837–847

1 3

We typically require the ipsilateral retrorectus space to be at least 7.5 cm wide to proceed with this approach. The pre-operative CT scan will allow the surgeon to measure the retrorectus space and make the appropriate decision on how to set up.

As demonstrated in Online Resource 1, the LUQ port is placed using an Applied Medical™ technique. Blunt dissec-tion with the camera is performed, followed by placement of a 12-mm robotic camera port and an 8-mm robotic LLQ port under direct vision into the developed left retrorectus space. The Applied Medical™ is then exchanged for a robotic 8-mm port. The robot is docked, and surgical dissection begins. With this setup, the crossover is achieved robotically, and not laparoscopically, as in the above-described setup methods. The crossover dissection is initiated in the previously unvio-lated area. Figure 7a–c demonstrates the crossover dissection and reconstruction of the linea alba.

Mesh placement

After closure of the posterior layer, a ruler is introduced into the 12-mm port, and the posterior area of the retro-rectus space is measured to adequately size and tailor the mesh. The mesh is introduced laparoscopically, unfurled, and placed against the posterior layer (Fig. 8a). Although the implant can be fixed with several interrupted sutures to the posterior layer or with fibrin sealant, we currently do not use any fixation for most cases. Retromuscular drain placement should be considered by the operating surgeon. In our practice, the need for chronic seroma intervention in these cases has been low. Once the mesh is positioned and flattened against the posterior layer, the retrorectus space is desufflated, and the ports are removed (Fig. 8b). Because the implanted mesh covers all port sites, port-site fascial defects are not closed.

Fig. 7 a–c Sequence of port placement in lateral defect repair

Fig. 8 a, b Mesh placement

844 Hernia (2018) 22:837–847

1 3

Special considerations

The laparoscopic eTEP access technique for ventral and incisional hernias has been around since 2015, and follow-up has been promising. It has always been our concern that the learning curve for the laparoscopic approach may be steep, requiring certain advanced laparoscopic technical skills. Surgeons should be aware that this is a novel robotic procedure, and long-term data are not yet available. We are pleased with our early outcomes, which are at least identi-cal to our extensive experience with the laparoscopic eTEP approach. In our experience, some of the technical and ergo-nomic challenges encountered in laparoscopic eTEP cases have been resolved with the addition of the robotic platform. We believe that adding robotic technology to this procedure will make it more reproducible and have long-lasting ben-efits for patients and surgeons.

Postoperative management

Most patients having robotic eTEP access Rives–Stoppa procedures are sent home on the same day of surgery; how-ever, those undergoing eTEP robotic transversus abdominal release may remain for an additional 23 h of observation. Diet is resumed after the resolution of intraoperative anes-thesia and when the patient is transferred from the post-anesthesia care unit.

Initial experiences

All patients who underwent robotic eRS or eTAR mesh repair of ventral, incisional, flank, or parastomal hernias were retrospectively queried from a database of hernia patients who underwent surgery at Anne Arundel Medical Center in Annapolis, Maryland, between March and October 2017. No patients during this time period were excluded from postoperative outcome analysis. Study data were col-lected and managed using Research Electronic Data Capture (REDCap) hosted at Anne Arundel Medical Center [11]. Descriptive statistics summarizing measures of central ten-dency and dispersion were performed using Microsoft Excel version 14.0 and IBM SPSS Statistics version 23 (Armonk, NY, USA). As this is a description of our initial experi-ences with this operative approach, no comparative statistics assessing subgroup analysis are presented.

Thirty-seven patients (13 male and 24 female) underwent abdominal wall reconstruction via robotic eTEP retromuscu-lar dissection between March and October of 2017 (Table 1). Patients were selected based on a combination of clinical

discretion and availability of the robot. The choice to utilize the eTAR technique, when selected, was determined not only based upon larger size defects (> 8 cm), but also con-sidered when dealing with a noncompliant abdominal wall, narrow unilateral retrorectus space (< 6 cm), or tension on the posterior layer during closure. There were no periopera-tive complications. Two patients developed subcutaneous seromas requiring interventional radiology drainage in the eTAR group. There were no SSIs in this cohort. One patient was readmitted within 30 days for PO intolerance in the eRS group that was managed conservatively. Mean postoperative follow-up visit occurred at 36 days (range 24–109 days) dur-ing which there was no evidence of early hernia recurrence.

Discussion

We describe a novel application of the eTEP access tech-nique for the repair of ventral, incisional, flank, and paras-tomal hernias utilizing the robotic platform. Despite only recently incorporating this technique into our practice, we have been able to successfully utilize this approach on 37 patients with minimal postoperative complications. Our short-term outcomes are encouraging with only two subcu-taneous seromas and one patient that required readmission to address oral intolerance.

Conventional herniorrhaphy with traditional laparoscopic TEP techniques, when utilized in inguinal hernia repair, places both ergonomic and spatial limitations on the sur-geon. Dr. Jorge Daes is credited with developing the eTEP approach for inguinal hernia repair first published in 2012 wherein a greater operative field of view is achieved [12]. Our center adopted this technique and applied the same prin-ciples to laparoscopic ventral and incisional hernia repairs starting in 2015 [1]. The laparoscopic eTEP access approach to ventral hernias is a versatile method to address a wide variety of abdominal wall defects, but retains its limitations in degrees of freedom for the surgeon and application to patients. The complexities associated with this approach would also likely pose obstacles to reproducibility in the hands of other surgeons [1]. In March 2017, we added the use of a robotic platform to this advanced MIS procedure in the hope that it will facilitate the execution of this techni-cally challenging operation to those surgeons who would chose to adopt it into their practices.

According to Moore et al., novice participants were able to perform surgical tasks more quickly and accurately using the robotic platform as well as showing transferability of surgical skills to more difficult tasks. This learning advan-tage was also maintained over an extended period of time and performing a surgical task under stressful multi-tasking conditions [13, 14]. Other studies have shown surgeons benefit from a more comfortable and ergonomic operating

845Hernia (2018) 22:837–847

1 3

position with high-resolution three-dimensional imagery and demonstrate improved dexterity due to increased degrees of freedom, motion scaling, and tremor filtering [15]. While reporting on the benefits of robotic ergonomics was outside the scope of this report, based on our first-hand experience we feel that implementation of robotic platform in this group of patients with mean BMI of 36 and requiring complex retromuscular dissection with suturing of wide anterior abdominal wall defects did offer technical improvement as compared to our previously reported laparoscopic eTEP experience [1]. However, benefits of the robotic platform are still not clear in the literature, as recently other authors have reported that robotic surgeons still suffer from chronic

pain related to poor intraoperative ergonomics [16]. As we are observing increased utilization of the robotic platform by the community of general surgeons at large, further studies will be needed to elucidate the benefits of robotic platform use in abdominal space.

Although other approaches to hernia repair are avail-able, our group aims to identify a means by which the operative field could be maximized while affording flex-ibility in repair of the complex anatomy and variation in the abdominal wall defect sizes. To this end, in March 2017, in combining the eTEP technique with the robotic platform, we successfully addressed a variety of ventral and atypical defect locations. The eTEP access technique

Table 1 Patient demographic and perioperative data

Patient demographics Mean ± SD/% Patient comorbidities n/% Patient comorbidities n/%

Number of patients (n) 37 Hypertension 19/51.4% Depression 3/8.1%Gender (male/female) 35%/65% Hyperlipidemia 17/45.9% Anxiety 3/7.9%Age (years) 54.1 ± 12.9 Gastroesophageal reflux disease 12/32.4% Deep vein thrombosis 2/5.4%Body mass index (kg/m2) 35.5 ± 8.3 Smoker 12/32.4% Pulmonary embolism 2/5.4%ASA score 2.4 ± 0.7 Recurrent hernia 8/21.6% Chronic renal disease 2/5.4%

Diabetes, type II 8/21.6% COPD 1/2.7%Asthma 6/16.2% Crohn’s disease 1/2.7%Anxiety 3/8.1% Colorectal cancer 1/2.7%

Surgical procedures n/%

Rives–Stoppa ReTEP (eRS) 29/78.4%Transversus abdominis release ReTEP (eTAR) 8/21.6%

Perioperative data [mean ± SD (range)] Total eRS eTAR

Procedure time (min) 162.6 ± 73.6 (70–430) 141.3 ± 48.8 (70–285) 240.1 ± 96.1 (120–430) Physician 1 (total = 25/eRS = 18/eTAR = 7) 149.4 ± 58.0 (70–310) 124.6 ± 31.6 (70–189) 213.0 ± 57.8 (120–310) Physician 2 (total = 12/eRS = 11/eTAR = 1) 190.3 ± 95.7 (86–430) 168.5 ± 58.8 (86–285) 430.0 ± 0 (430–430)

Size of hernia defect (greatest dimension) (cm) 7.4 ± 3.7 (1.5–16.4) 5.9 ± 2.7 (1.5–10.7) 11.3 ± 3.5 (6.5–16.4)Size of mesh (greatest dimension) (cm) 19.0 ± 5.3 (11.0–30.0) 16.7 ± 3.0 (11.0–23.0) 27.1 ± 3.3 (22.0–30.0)Mesh area (cm2) 613.7 ± 235.9 (240.0–1200.0) 532.7 ± 162.9.0 (240.0–840.0) 907.1 ± 225.0 (528.0–1200.0)LOS (days) 0.7 ± 1.0 (0–4) (x̃ = 0) 0.3 ± 0.5 (0–1) (x̃ = 0) 2.1 ± 1.3 (1–4) (x̃ = 2)Postoperative follow-up (days) 36 ± 18.6 (24–109) 31 ± 8.4 (24–60) 53 ± 30.2 (31–109)

Hernia type n/% Hernia location n/% Robotic docking n/%

Primary ventral 18/49% Lower midline 16/43% Upper 23/59%Ventral incisional 15/41% Upper midline 14/38% Lower 8/22%Flank 3/8% Lateral 7/19% Side 7/19%Parastomal 1/3%

Wound-related compli-cations (n/%)

Total eRS eTEP Non-wound-related com-plications (n/%)

Total eRS eTEP

Seroma 2 (5.4%) 0 (0.0%) 2 (25.0%) Oral intolerance 1 (2.7%) 1 (3.4%) 0 (0.0%)Hematoma 0 (0.0%) 0 (0.0%) 0 (0.0%) Prolonged ileus 0 (0.0%) 0 (0.0%) 0 (0.0%)SSI 0 (0.0%) 0 (0.0%) 0 (0.0%) UTI 0 (0.0%) 0 (0.0%) 0 (0.0%)Skin necrosis 0 (0.0%) 0 (0.0%) 0 (0.0%) ARF 0 (0.0%) 0 (0.0%) 0 (0.0%)Wound dehiscence 0 (0.0%) 0 (0.0%) 0 (0.0%) Respiratory 0 (0.0%) 0 (0.0%) 0 (0.0%)

DVT/PE 0 (0.0%) 0 (0.0%) 0 (0.0%)

846 Hernia (2018) 22:837–847

1 3

offers use of the retromuscular space and allows for com-plete exclusion of mesh from the peritoneal cavity, thus avoiding direct contact between mesh and visceral con-tents which may reduce the possibility of future postop-erative gastrointestinal complications such as intestinal erosion, bowel obstruction, or fistula formation. Selective utilization of transversus abdominis release can also be used when indicated.

All eRS and eTAR cases in our cohort were performed as a single robotic dock approach, eliminating the need for additional ports and the time needed for re-docking steps. Moving from a traditional transabdominal approach may also lead to a subsequent decrease in port site hernia for-mation, as at the completion of the case all port sites in eTEP access approach are covered with mesh. Penetrating transfascial fixation has been completely eliminated with this technique as wide-size mesh is sandwiched in between posterior and anterior layers of the abdominal wall [1].

This series represents the first instance of a robotic approach to the eTEP technique, having evolved from our experience with laparoscopic eTEP ventral hernia repair [1]. Our results demonstrate that minimally invasive extra-peritoneal retromuscular approach to abdominal wall her-nia repair is associated with low intraoperative blood loss, few postoperative complications and short length of stay. These findings are greatly encouraging as has been shown in a recent cost analysis that conversion of open abdominal wall reconstruction cases to a minimally invasive surgical approach can lead to significant reductions in hospital stay that translate into reduced total hospital costs per case [17].

There are several important limitations that bear empha-sis, including the lack of longer term follow-up in this par-ticular cohort at this juncture. In addition, our findings are limited to the experience of two robotic surgeons (IB and HRZ) at a very specialized hernia center. While all patients with abdominal wall defects entering our program are viewed as potential candidates for eRS and eTAR proce-dures, there are certain selection biases among these cases. Patients with past history of active infection as well as those that were considered unsafe for laparoscopic access were deemed poor operative candidates for this procedure. Fur-thermore, as we currently have limited access to the robotic platform with IB once a week and HRZ twice a month, we preferentially selected patients that are viewed as more dif-ficult case scenarios. For example, higher BMI patients, cases with recurrent defects, and re-operative area were more likely to be selected for robotic eRS and eTAR than the laparoscopic eTEP approach that we still frequently per-form at our facility. In addition, large defects with previous sternum to pubis incisions were addressed with traditional transabdominal double-dock robotic TAR approach and were not considered for eTEP access approach as crossover in those cases may be unsafe [2, 18].

Reproducibility of this robotic technique has yet to be established by the surgical community as a whole. Perhaps of greatest importance when considering successful comple-tion of these cases is the need for the operating surgeon to have a complete understanding of retromuscular anatomy. Lack of anatomical appreciation will result in high postop-erative morbidity and irreversible damage to the function of the abdominal wall [19, 20]. Strong consideration should be given to becoming closely familiar with the works of Rives and Stoppa as well as more recent work by Novitsky, Car-bonell and Ballecer [8, 9, 18, 21]. Furthermore, the robotic platform is an advanced MIS tool and its use is associated with an appreciable learning curve. To this end, success-ful execution of the robotic-assisted eRS and eTAR proce-dures requires the operating surgeon to be proficient in the use of a robotic platform. Attempts to determine standard-ized methods of achieving proficiency have been proposed, mostly involving simulated operative experiences during which the robotic platform is utilized [22, 23]. However, as yet there remains wide variability in scoring metrics and tasks required to claim this degree of mastery. Mastering the learning curves associated both with the robotic platform as well as the eRS and eTAR techniques at the same time is unadvised.

Conclusion

As a natural evolution of previously established minimally invasive techniques, the robotic-assisted endoscopic retro-muscular mesh repair has been reproducible in our early experience. The 30-day outcomes have been consistent with past eTEP laparoscopic experience.

Acknowledgements Figures are reprinted from “Robotic Extended-View Totally Extraperitoneal Access Rives-Stoppa Repair”, by Belyan-sky I, Sanford Z, Weltz AS, Zahiri HR, 2018, Atlas of Robotic Surgery. Copyright (2018) by Ciné-Med, Inc.

Compliance with ethical standards

Conflict of interest Dr. Igor Belyansky’s disclosures are honoraria and consulting fees from Intuitive, Bard, Medtronic, and Allergan. Drs. H. Reza Zahiri, Zachary Sanford, Adam S. Weltz, and Adrian E. Park have no conflicts of interest or financial ties to disclose.

Ethical approval All procedures performed in studies involving human participants were in accordance with ethical standards of the institu-tional and/or national research committee and with the 1964 Helsinki declaration and its amendments or comparable ethical standards.

Human and animal rights This article does not contain any studies with animals performed by any of the authors.

Informed consent All authors certify that they accept responsibility as an author and have contributed to the concept, data gathering, analysis, manuscript drafting, and give their final approval.

847Hernia (2018) 22:837–847

1 3

References

1. Belyansky I, Daes J, Radu VG, Balasubramanian R, Reza Zahiri H, Weltz AS, Sibia US, Park A, Novitsky Y (2017) A novel approach using the enhanced-view totally extraperitoneal (eTEP) technique for laparoscopic retromuscular hernia repair. Surg Endosc 32:1525–1532

2. Martin-Del-Campo LA, Weltz AS, Belyansky I, Novitsky YW (2017) Comparative analysis of perioperative outcomes of robotic versus open transversus abdominis release. Surg Endosc 32:840–845

3. Berguer R, Smith W (2006) An ergonomic comparison of robotic and laparoscopic technique: the influence of surgeon experience and task complexity. J Surg Res 134:87–92

4. van der Schatte Olivier RH, Van’t Hullenaar CD, Ruurda JP, Broeders IA (2009) Ergonomics, user comfort, and performance in standard and robot-assisted laparoscopic surgery. Surg Endosc 23:1365–1371

5. Szold A, Bergamaschi R, Broeders I, Dankelman J, Forgione A, Lango T, Melzer A, Mintz Y, Morales-Conde S, Rhodes M, Satava R, Tang CN, Vilallonga R, European Association of Endo-scopic S (2015) European Association of Endoscopic Surgeons (EAES) consensus statement on the use of robotics in general surgery. Surg Endosc 29:253–288

6. Plerhoples TA, Hernandez-Boussard T, Wren SM (2012) The aching surgeon: a survey of physical discomfort and symptoms following open, laparoscopic, and robotic surgery. J Robot Surg 6:65–72

7. Petro CC, Como JJ, Yee S, Prabhu AS, Novitsky YW, Rosen MJ (2015) Posterior component separation and transversus abdominis muscle release for complex incisional hernia repair in patients with a history of an open abdomen. J Trauma Acute Care Surg 78:422–429

8. Novitsky YW, Fayezizadeh M, Majumder A, Neupane R, Elliott HL, Orenstein SB (2016) Outcomes of posterior component sepa-ration with transversus abdominis muscle release and synthetic mesh sublay reinforcement. Ann Surg 264:226–232

9. Novitsky YW, Elliott HL, Orenstein SB, Rosen MJ (2012) Trans-versus abdominis muscle release: a novel approach to posterior component separation during complex abdominal wall reconstruc-tion. Am J Surg 204:709–716

10. Blatnik JA, Krpata DM, Novitsky YW (2016) Transversus abdominis release as an alternative component separation tech-nique for ventral hernia repair. JAMA Surg 151:383–384

11. Harris PATR, Thielke R, Payne J, Gonzalez N, Conde JG (2009) Research electronic data capture (REDCap)—a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform 42:377–381

12. Daes J (2012) The enhanced view-totally extraperitoneal tech-nique for repair of inguinal hernia. Surg Endosc 26:1187–1189

13. Moore LJ, Wilson MR, Waine E, Masters RS, McGrath JS, Vine SJ (2015) Robotic technology results in faster and more robust surgical skill acquisition than traditional laparoscopy. J Robot Surg 9:67–73

14. Park BS, Ryu DY, Son GM, Cho YH (2014) Factors influencing on difficulty with laparoscopic total extraperitoneal repair accord-ing to learning period. Ann Surg Treat Res 87:203–208

15. Smith CD, Farrell TM, McNatt SS, Metreveli RE (2001) Assess-ing laparoscopic manipulative skills. Am J Surg 181:547–550

16. Lee GI, Lee MR, Green I, Allaf M, Marohn MR (2017) Surgeons’ physical discomfort and symptoms during robotic surgery: a com-prehensive ergonomic survey study. Surg Endosc 31:1697–1706

17. Belyansky I, Weltz AS, Sibia US, Turcotte JJ, Taylor H, Zahiri HR, Turner TR, Park A (2017) The trend toward minimally inva-sive complex abdominal wall reconstruction: is it worth it? Surg Endosc 32:1701–1707

18. Carbonell AM, Warren JA, Prabhu AS, Ballecer CD, Janczyk RJ, Herrera J, Huang LC, Phillips S, Rosen MJ, Poulose BK (2017) Reducing length of stay using a robotic-assisted approach for ret-romuscular ventral hernia repair. A comparative analysis from the Americas Hernia Society quality collaborative. Ann Surg 267:210–217

19. Gibreel W, Sarr MG, Rosen M, Novitsky Y (2016) Technical con-siderations in performing posterior component separation with transverse abdominis muscle release. Hernia 20:449–459

20. Krpata DM, Blatnik JA, Novitsky YW, Rosen MJ (2012) Posterior and open anterior components separations: a comparative analy-sis. Am J Surg 203:318–322 (discussion 322)

21. Ballecer C, Prebil B (2015) Robotic Rives-Stoppa incisional her-nia repair with bilateral posterior component separation. Abdom Wall Repair J 3:12–16

22. Hogg ME, Tam V, Zenati M, Novak S, Miller J, Zureikat AH, Zeh HJ III (2017) Mastery-based virtual reality robotic simulation curriculum: the first step toward operative robotic proficiency. J Surg Educ 74:477–485

23. Bric J, Connolly M, Kastenmeier A, Goldblatt M, Gould JC (2014) Proficiency training on a virtual reality robotic surgical skills curriculum. Surg Endosc 28:3343–3348

Early operative outcomes of endoscopic (eTEP access) robotic-assisted retromuscular abdominal wall hernia repairAbstractBackground Methods Results Conclusion

IntroductionThe robotic extended-view totally extraperitoneal (eTEP) access Rives–Stoppa techniquePreoperative considerationsAccess and port placementRelevant anatomy and the principles of crossoverUpper midline defects (lower dock setup)Lower midline defects (upper dock setup)Lateral dock setupMesh placementSpecial considerationsPostoperative managementInitial experiencesDiscussionConclusionAcknowledgements References