• Users Online: 93
  • Print this page
  • Email this page

Table of Contents
Year : 2022  |  Volume : 5  |  Issue : 3  |  Page : 103-109

Robotic transversus abdominis release for ventral hernia repairs

Department of Surgery, Creighton University School of Graduate Medical Education Phoenix, Arizona, USA

Date of Submission18-Sep-2021
Date of Decision30-Oct-2021
Date of Acceptance11-Nov-2021
Date of Web Publication01-Sep-2022

Correspondence Address:
Tiffany Nguyen
Department of Surgery, Creighton University School of Graduate Medical Education, 500 W Thomas Rd Ste 400, Phoenix, AZ 85013
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijawhs.ijawhs_62_21

Rights and Permissions

Background: Robotic transversus abdominis release (roboTAR) is a minimally invasive surgical approach for ventral hernia repairs that builds on the concepts developed by Rives and Stoppa. The Rives–Stoppa procedure incorporates Rives’ retromuscular repair and Stoppa’s concept of giant prosthetic reinforcement of the visceral sac (GPRVS).[1] In an effort to mitigate the limitations of the Rives–Stoppa procedure, Novitsky et al. developed the open transversus abdominis release (TAR). The TAR approach is favorable when repairing large ventral hernia defects, as it provides myofascial advancement to reconstitute linea alba, preserves the neurovascular bundles of the medial abdominal wall, and creates a large extraperitoneal space to allow for mesh reinforcement. Methods: The three main technical components of the roboTAR include the following: bottom-up, Novitsky method, and top-down approach. An understanding of the anatomy and technique involved in the three techniques is critical for performing roboTAR. Results: Within the authors’ practice, the average hernia defect size is 115 cm2. With a n = 200, approximately 1% of our patients has had a surgical site complication. Recurrences are rare and occur in very large complex hernias. The average operative time is approximately 400 min with an average length of stay being 1.2 days. This is consistent with others. Conclusion: Utilizing a minimally invasive approach, as seen in roboTAR, provides additional advantages, including shorter length of hospital stay, reduced wound morbidity, reduced postoperative pain, and expedited return to work and activities of daily living. This article is a comprehensive review of the pertinent anatomy, preoperative evaluation, operative technique, and the postoperative course of roboTAR.

Keywords: Bottoms-up TAR, critical view of TAR, Novitsky, posterior component separation, retromuscular, rives, robotic, Stoppa, sublay, top-down TAR, transversus abdominis release, ventral hernia

How to cite this article:
Nguyen T, Kunes K, Crigler C, Ballecer C. Robotic transversus abdominis release for ventral hernia repairs. Int J Abdom Wall Hernia Surg 2022;5:103-9

How to cite this URL:
Nguyen T, Kunes K, Crigler C, Ballecer C. Robotic transversus abdominis release for ventral hernia repairs. Int J Abdom Wall Hernia Surg [serial online] 2022 [cited 2023 Jan 28];5:103-9. Available from: http://www.herniasurgeryjournal.org/text.asp?2022/5/3/103/355262

  Introduction Top

Robotic transversus abdominis release, also known as roboTAR, is gaining traction as an effective minimally invasive technique to repair large ventral hernias. RoboTAR is a culmination of the advances made by many of the pioneers throughout the history of ventral hernia repairs. The open transversus abdominis release (TAR) was first described by Novitsky et al.[1] The open TAR results in the reconstitution of the linea alba without the division of the neurovascular bundles. This is accomplished by medializing the rectus muscles via division of the transversus abdominis (TA) along its entire length allowing for a large extraperitoneal plane to be developed. The neurovascular bundles are preserved by opening the posterior rectus sheath laterally to gain exposure to the TA.

The robotic approach allows for the separation of the posterior components without creating large lipocutaneous flaps, which are associated with complications such as skin ischemia, necrosis, and recurrent seromas. A large preperitoneal space, not limited by the linea semilunaris, can be created due to the extensive myofascial release obtained, thus allowing for giant prosthetic mesh reinforcement.[2] Advantages of roboTAR include shorter length of hospital stay, reduced wound morbidity, reduced postoperative pain, and expedited return to work and activities of daily living.[3] Furthermore, certain populations considered high risk including those with diabetes mellitus, body mass index (BMI) > 30, and present tobacco use have had encouraging outcomes as well.[4],[5],[6]

Historically, open TAR is associated with significant patient morbidity, longer length of stay, wound infections, and postoperative pain. Carbonell et al.[7] showed a significantly shorter duration of hospitalization in the group that underwent robotic surgery when compared to open ventral hernia repair (2 vs. 3 days, P < 0.001). Although indications for performing a robotic TAR vs. open TAR for large ventral hernia repairs are similar, the minimally invasive approach improves clinical outcomes when compared to the open approach by significantly decreasing length of hospital stay and surgical site complications.

  Preoperative Evaluation and Patient Selection Top

A comprehensive history and physical examination are crucial to obtain for the purpose of determining candidacy for roboTAR and developing a surgical plan. Key components to ascertain include smoking, obesity, diabetes, collagen vascular disorders, and prior surgical history, as these factors may impact operative planning. We recommend that patients attempt weight loss, optimize their blood glucose levels (HgbA1c < 7), and quit smoking at least 4 weeks before surgery. Ideally, a patient’s BMI should be <35; however, a max limit of 40 is acceptable. A preoperative abdominal computed tomography (CT) is mandatory to allow for evaluation of the abdominal wall cavity and defect size.

The Carbonell’s equation can be used to assess if a patient is a good candidate for roboTAR.[8],[9] If the sum of the width of the recti is twice the size of the defect, a Rives–Stoppa technique is adequate; however, if the ratio is less than 2, TAR should be considered. In addition, a TAR, whether robotic or open, is also recommended in patients with large defects greater than 10–12 cm, recurrent peristomal hernias, lateral wall defects, and ostomies.[10]

Contraindications to roboTAR are similar to those of other laparoscopic surgeries. Patients who cannot tolerate pneumoperitoneum should not undergo roboTAR. Patients with extensive adhesions and “frozen” abdomens are not suitable as well. Other circumstances that may contraindicate roboTAR include extensive loss of domain secondary to large abdominal wall hernias, defects that extend from flank to flank, and poor skin integrity/ulceration. Furthermore, patients who need a panniculectomy or abdominoplasty should not receive a completely robotic surgical approach, though a hybrid approach may be appropriate.[11] Lastly as mesh is placed into the field, we recommend performing roboTAR only in clean cases.

  Ethics committee approval Top

It was not applicable for this article.

  Operative Technique Top

Entering the abdomen

The patient should be placed supine with the arms tucked with all pressure points adequately padded. Generally, intraabdominal access is achieved under direct visualization via an optical trocar in the left upper quadrant lateral to Palmer’s point. However, a right upper quadrant optical entry is an option if necessary due to prior surgical history. 8 mm trocars are placed in the left upper quadrant, left lateral mid-abdomen, and left lower quadrant. In patients with shorter torsos, additional space for trocar insertion can be achieved via bed flexion which creates more space between the costal margin and the iliac crest. However, the extent of bed flexion must be monitored carefully to avoid causing back pain or spinal trauma, especially in patients with prior back injury or surgical history. Once the trocars are in place, the robot is positioned above the contralateral abdomen and is docked [Figure 1].
Figure 1: Initial robotic port placement with contralateral ports placement for double docking

Click here to view

Division of the posterior rectus sheath and subsequent mobilization to the semilunaris

The abdominal wall is then evaluated in its entirety. Lysis of adhesions and hernia sac reduction must be completed carefully to prevent injury to the abdominal viscera. The patient may have concomitant inguinal hernias; therefore, complete abdominal wall clearance is needed for full evaluation. Retromuscular access is obtained by incising the posterior sheath. The initial incision on the posterior sheath should be approximately 1–2 cm from the medial rectus, which will allow for adequate fascial visualization prior to anterior sheath closure. The dissection is performed while keeping the rectus abdominis muscle fibers up against the abdominal wall and the posterior elements (posterior rectus sheath, underlying transversalis fascia, and peritoneum) on the floor. This may be difficult to accomplish in patients with atrophic recti or if this plane has been accessed for prior surgery. The dissection is carried out laterally until the linea semilunaris has been reached and the neurovascular bundles are identified [Figure 2]. The neurovascular bundles must be preserved to avoid devascularization and denervation of the rectus muscle.
Figure 2: Posterior rectus sheath that has been divided and the dissection continued laterally until the semilunar line is reached. It is critically important to identify the neurovascular bundles to avoid denervation to the rectus abdominis muscle

Click here to view

The retrorectus dissection is continued cephalad until the epigastric crossover is performed cephalad to the hernia defect. The falciform ligament is brought down with the flap. To ensure the flap is continuous with the posterior rectus sheath, care is taken to dissect all preperitoneal fat posteriorly and away from the linea alba. Caudally, the retrorectus dissection is continued below the arcuate line, and a preperitoneal flap is created that is continuous with the posterior rectus sheath. The suprapubic cross over results in a preperitoneal flap to the level of the space of Retzius. Cooper’s ligament should be visualized and any concomitant inguinal, obturator, and/or femoral hernias identified should be reduced and repaired at this time. The dissection is carried out laterally until the arcuate line is visible at the level of the linea semilunaris. Inferior to the cross-section of the arcuate line and the linea semilunaris, the transversalis fascia is incised to enter the preperitoneal plane.

In order to dissect the space of Bogros, the preperitoneal fat is swept downward and the dissection is carried out laterally until the TA muscle is visualized along the lateral abdominal wall. The inferior epigastric vessel is a good landmark for the suprapubic crossover as well as a key landmark for the myopectineal orifice. Dissection is continued laterally and posteriorly to the inferior epigastric vessels until the TA is identified laterally on the abdominal wall, which signifies the start for the bottom-up TAR.

Three ways to transversus abdominis release

There are three ways to perform a TAR: bottom-up, Novitsky method, and top-down. The author prefers to use a combination of all three. A comprehensive understanding of all three techniques is critical, given that intraoperative findings of anatomical or visceral variations may dictate a different approach than originally planned.

Bottom-up technique

Beginning in a caudal to cephalad version, the TA is divided starting at the Space of Bogros to initiate the TAR. The posterior elements (peritoneum, transversalis fascia, and preperitoneal fat) are separated from the overlying TA muscle and lateral posterior sheath. The preperitoneal cave is developed as the dissection is continued, and the posterior elements are preserved. Dissection is performed in a medial direction along the line of reflected peritoneum once the lateral extent of dissection of retroperitoneal fat is reached. The aponeurotic portion of the TA is now isolated within this large preperitoneal cave. The posterior elements are retracted in a cephalad and medial direction creating a “V” shape to delineate the preserved posterior elements from the aponeurotic portion of TA [Figure 3]. The dotted line shows the area safe for division, which is medial to the neurovascular bundle and semilunar line.
Figure 3: Bottom-up technique. A large preperitoneal cave is created isolating the aponeurotic portion of the transversus abdominis. The transversus abdominis release (TAR) is continued along the dotted line along the transversus abdominis (TA) aponeurosis

Click here to view

Continuing cephalad to the mid-abdominal region, there is a loss of preperitoneal fat. At this point, it is often required to transition dissection between the preperitoneal to the pre-transversalis fascia planes or between the anterior and posterior leaflets of the transversalis fascia. Furthermore, the aponeurotic portions of the TA becomes more muscular and more difficult to dissect. Once the bottom-up technique becomes too difficult, a transition is made to the Novitsky technique or the top-down approach.

Novitsky method

In the upper third of the abdomen, the muscle belly of the TA inserts more medially on the posterior sheath. The neurovascular bundle needs to be clearly identified to avoid denervation of the rectus muscle complex. Medial to the neurovascular bundles, the posterior lamella of the internal oblique is incised exposing the TA muscle fibers [Figure 4]. The TA muscle is carefully transected showing the underlying transversalis fascia. This dissection exposes the transversalis fascia and is continued laterally until the retroperitoneal fat pad is identified. The Novitsky method can be connected with the top-down and bottom-up approach to complete the TAR dissection.
Figure 4: Novitsky method. The posterior lamella of the internal oblique (PLIO) is incised to reveal the muscle fibers of the transversus abdominis (TA). Monopolar scissors are used to lift up the TA and transect it. Care is taken to avoid any injury to the neurovascular bundles (NVB)

Click here to view

Top-down technique

We begin in the preperitoneal space at the prior epigastric crossover [Figure 5]. Preperitoneal/pretransversalis dissection is carried laterally towards the retroperitoneal fat underneath the diaphragm and the TA on the lateral abdominal wall. There is a sentinel fat pad that can aid in identifying the TA fibers from the fibers of the diaphragm. Dissection into the diaphragm can result in iatrogenic diaphragmatic hernia and inadvertent entry into the thoracic cavity. A preperitoneal/pretransversalis cave is created to preserve the posterior elements (peritoneum and transversalis fascia) while separating the overlying TA muscle which inserts on lateral on the posterior sheath. The diaphragm and TA muscles fibers are left on the anterolateral abdominal wall. The TA is then incised upon completion of the preperitoneal cave.
Figure 5: Top-down TAR is similar to bottom-up TAR in terms of creating a preperitoneal cave. The posterior elements (peritoneum and transversalis fascia) are separated from the posterior sheath to create a “V.” Care must be taken to avoid injury at the linea semilunaris to the neurovascular bundles. If the diaphragm fibers are brought down inadvertently, a Morgagni hernia (MH) can be created

Click here to view

Once all three techniques have been performed top-down, bottom-up, and Novitsky way, the dissection planes will coalesce [Figure 6]. There will be a single pedicle of TA that can be easily divided without injuring the posterior elements to join all three dissections into one plane. Posterior coverage of the mesh is provided by the posterior rectus sheath, the transversalis fascia, and peritoneum. The critical view or sine qua non of TAR is achieved when the cut edge of TA is shown on the lateral abdominal wall medial to the neurovascular bundles and linea semilunaris and the cut edge of TA is observed on the posterior sheath with no muscular layer on the posterior elements. To ensure the posterior sheath is flat over the viscera without tenting or tension, dissection of the posterior layer can be continued to the retroperitoneal fat or the lateral border to the psoas.
Figure 6: Sine qua non of TAR. Critical view of TAR in the upper abdomen is the cut edge of TA on the abdominal wall, cut edge of TA on the posterior sheath and no additional muscle on the posterior elements. The flap lay nice and flat on top of the viscera without any undue tension

Click here to view

Initial deployment and fixation of mesh

The dissection must be large enough to ensure giant prosthetic reinforcement of the visceral sac; the degree of dissection is based on the longitudinal and horizontal size of the defect to ensure adequate craniocaudal overlap. A minimum of 5 cm of overlap on either side is recommended but oftentimes we exceed this to ensure adequate reinforcement. Once the dissection is completed on one side, the craniocaudal length of dissection and the extent of the flank to midline dissection is measured to choose the appropriately sized mesh.

The “Suture trick” uses the placement of an absorbable suture in the center of the mesh with a long tail to facilitate unscrolling of the mesh once placed on the posterior elements. The mesh is rolled and prepared for insertion into the abdomen. Contralateral ports are placed above the mesh after its initial deployment on the lateral abdominal wall if a bilateral TAR is indicated. We prefer large pore polypropylene synthetic mesh. The rolled mesh is placed in the retromuscular and preperitoneal/pretransversalis space and is fixated with sutures along the posterolateral abdominal wall prior to dissection.

Contralateral dissection and double docking

If a bilateral TAR is indicated, a double docking technique is used and three 8 mm trocars are placed on the opposite side of the abdomen, mirroring the initial three trocars. Perform the contralateral tar as described above. To ensure sufficient cephalad-caudal overlap of the hernia defeat, retro-xiphoidal or retropubic dissection may be needed. Confirmation of adequate TAR dissection is achieved when the two leaves of the posterior sheath rests flat against the abdominal visceral without undue tension.

Closure of the posterior and anterior rectus sheath

If there are peritoneal defects, they should be closed with an absorbable suture prior to closure of the sheaths. Using a barbed suture in a running Connell Fashion the posterior sheath is re-approximated to minimize the contact between barbed suture and bowel [Figure 7]. Likewise, the anterior fascia is re-approximated; to aid in its closure the pneumoperitoneum can be reduced to 6–10 mmHg [Figure 8]. To minimize the risk of seroma formation, the dome of the defect should be included within the anterior sheath closure to obliterate dead space. The linea alba is now restored.
Figure 7: Posterior sheath is closed

Click here to view
Figure 8: Anterior rectus is brought back together and the linea alba is reconstituted

Click here to view

Final mesh deployment

The mesh is unscrolled by the pulling on the suture that was previously placed in the center of the mesh. The mesh should lay flat atop the posterior sheath and elements. In the author’s practice, a single retromuscular drain is placed under direct visualization through one of the available ports. Hemostatic agents such as powder or glue can be used at this time with the goal of preventing hematoma and seroma formation.

  Discussion Top

The robotic platform offers a minimally invasive approach for repair of complex ventral hernias using TAR. [Table 1] is a summary of the comparison between the outcomes of open TAR vs. roboTAR. When looking at 90-day outcomes between roboTAR and open TAR in comparable patients, operative time was longer in the roboTAR cohort (287 ± 121 vs. 365 ± 78 min, P < 0.01); however, the roboTAR cohort had lower morbidity (39.2 vs. 19.2%, P = 0.09), less severe complications, and similar rates of readmissions and surgical site infections (2.6 vs. 3.8%, P = 1.00). Furthermore, length of hospital stay was significantly decreased in the roboTAR cohort (6 days, 95% CI 5.9–8.3 vs. 3 days, 95% CI 3.2–4.3).[4] Martin-Del-Campo et al.[5] revealed that use of the robotic platform for TAR significantly improved clinical outcomes by minimizing blood loss during surgery, reducing length of hospital stay (6.0 ± 3.4 days vs. 1.3 ± 1.3, P < 0.001), and decreased incidence of ileus, deep vein thrombosis, pulmonary embolism, and pneumonia. Of note, this study showed zero surgical site infections with the robotic approach when compared to the open approach, which is a major advantage considering surgical site infections are a prominent complication of open ventral hernia repairs. However, the authors report the difference was not statistically different likely due to type II error. In addition, although this study showed prolonged operative time with the robotic approach (211 ± 63 min vs. 299 ± 95, P < 0.001), operative time should decrease with experience as proficiency is achieved. Although existing data reveal that the robotic approach to hernia repairs is advantageous in terms of shorter length of hospital stay and potentially decreased surgical site infections compared to the open approach, more research is required to fully understand the impact of the robotic approach on clinical outcomes.
Table 1: Comparison of open transversus abdominis release vs. roboTAR

Click here to view

In our practice with a n = 200, the average hernia defect size is 115 cm2 in patients undergoing roboTAR. With the myofascial release obtained, the average mesh area is 500 cm2 which provides ample visceral reinforcement. Approximately 1% of our patient has had a surgical site complication, which include 1 mesh infection and 1 mesh exposure. Recurrence occurred in three midline hernia repair and in 1 bilateral flank hernia repair. Recurrences are rare and occur in very large complex hernias. The average operative time for the roboTAR is approximately 400 min. Similar to others, the average length of stay is 1.2 days. The shortened length of stay in the robotic platform may be related to decrease postoperative pain. Despite the learning curve associated with the robotic platform, outcomes data and our data have shown that the robotic approach is superior. With increasing case volumes, the surgeon’s proficiency will be quickly achieved with the robotic platform and operative times should decrease.

  Conclusion Top

The robotic surgical platform allows for a safe and minimally invasive approach to complex ventral hernias and allows for abdominal wall reconstruction with TAR. The nature of the robotic platform requires thorough understanding of abdominal wall anatomy, spatial awareness, and extensive knowledge regarding the operative techniques. Misidentification of the linea semilunaris can lead to potential denervation and devascularization of the rectus abdominis muscle. Furthermore, inadvertent division of the diaphragm muscle fibers superiorly can cause iatrogenic Morgagni hernia and even entry into the thoracic cavity. Thus, thorough knowledge of the abdominal wall musculature, innervation, vascular supply, and bony anatomy is crucial. The critical view of roboTAR is achieved when the cut edge of TA is seen on the lateral abdominal wall as well as the cut edge of TA on the posterior sheath. The posterior elements should be clear of any musculature. When this view has been obtained, then the TAR has been successfully completed. Despite the longer operative times at first, the robotic platform has comparable outcome data and perhaps superior to the open technique in terms of length of stay, wound morbidity, and cost. Given the novelty of the robotic approach, more research and experience are needed to evaluate long-term outcomes.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Novitsky YW, Elliott HL, Orenstein SB, Rosen MJ Transversus abdominis muscle release: A novel approach to posterior component separation during complex abdominal wall reconstruction. Am J Surg 2012;204:709-16.  Back to cited text no. 1
Majumder A, Miller HJ, Del Campo LM, Soltanian H, Novitsky YW Assessment of myofascial medialization following posterior component separation via transversus abdominis muscle release in a cadaveric model. Hernia 2018;22:637-44.  Back to cited text no. 2
Pauli EM, Rosen MJ Open ventral hernia repair with component separation. Surg Clin North Am 2013;93:1111-33.  Back to cited text no. 3
Bittner JG 4th, Alrefai S, Vy M, Mabe M, Del Prado PAR, Clingempeel NL Comparative analysis of open and robotic transversus abdominis release for ventral hernia repair. Surg Endosc 2018;32:727-34.  Back to cited text no. 4
Martin-Del-Campo LA, Weltz AS, Belyansky I, Novitsky YW Comparative analysis of perioperative outcomes of robotic versus open transversus abdominis release. Surg Endosc 2018;32:840-5.  Back to cited text no. 5
Gonzalez A, Escobar E, Romero R, Walker G, Mejias J, Gallas M, et al. Robotic-assisted ventral hernia repair: A multicenter evaluation of clinical outcomes. Surg Endosc 2017;31:1342-9.  Back to cited text no. 6
Carbonell AM, Warren JA, Prabhu AS, Ballecer CD, Janczyk RJ, Herrera J, et al. Reducing length of stay using a robotic-assisted approach for retromuscular ventral hernia repair: A comparative analysis from the Americas Hernia Society Quality Collaborative. Ann Surg 2018;267:210-7.  Back to cited text no. 7
Radu VG, Lica M The endoscopic retromuscular repair of ventral hernia: The eTEP technique and early results. Hernia 2019;23:945-55.  Back to cited text no. 8
Love MW, Warren JA, Davis S, Ewing JA, Hall AM, Cobb WS, et al. Computed tomography imaging in ventral hernia repair: Can we predict the need for myofascial release? Hernia 2021;25:471-7.  Back to cited text no. 9
Amaral MVFD, Guimarães JR, Volpe P, Oliveira FMM, Domene CE, Roll S, et al. Robotic transversus abdominis release (TAR): Is it possible to offer minimally invasive surgery for abdominal wall complex defects? Rev Col Bras Cir 2017;44:216-9.  Back to cited text no. 10
Novitsky YW Atlas of Robotic General Surgery. 1st ed. Philadelphia, PA: Elsevier; 2022. p. 127-40.  Back to cited text no. 11


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8]

  [Table 1]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
   Preoperative Eva...
   Ethics committee...
  Operative Technique
   Article Figures
   Article Tables

 Article Access Statistics
    PDF Downloaded128    
    Comments [Add]    

Recommend this journal