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Open posterior component separation techniques

Open posterior component separation techniques
Author:
Clayton C Petro, MD
Section Editor:
Michael Rosen, MD
Deputy Editor:
Wenliang Chen, MD, PhD
Literature review current through: Jan 2024.
This topic last updated: Aug 23, 2023.

INTRODUCTION — Component separation is an abdominal wall reconstructive technique that strategically divides the rectus and lateral abdominal wall musculofascial layers in order to achieve tension-free midline fascial approximation.

Depending on the muscle(s) divided, the techniques of component separation can be broadly categorized into anterior and posterior. Posterior component separation techniques include the Rives-Stoppa retrorectus dissection and transversus abdominis release (TAR).

This topic will discuss the technical details of open posterior component separation operations. The relevant anatomy and patient selection criteria, as well as the efficacy and complications of component separation, are discussed in another topic. (See "Overview of component separation".)

Anterior component separation techniques and robotic component separation techniques are discussed elsewhere. (See "Open anterior component separation techniques" and "Robotic component separation techniques".)

GENERAL PRINCIPLES — Posterior component separation is performed in an orderly, progressive fashion.

Rives-Stoppa retrorectus dissection — A retrorectus dissection, originally described in the 1980s by French surgeons Jean Rives and René Stoppa [1], is initiated by medial division of the posterior rectus sheath. However, the lateral extent of the Rives-Stoppa retrorectus dissection is limited by the linea semilunaris.

Division of posterior lamella of internal oblique — Division of the posterior lamella of the internal oblique (IO) just medial to the linea semilunaris would allow for an intramuscular dissection between the IO and transversus abdominis (TA) muscles, which in theory permits medialization of the rectus and creation of a large intramuscular space [2]. However, this operation has a notable limitation that quelled its adoption; an intramuscular dissection between the IO and TA requires uniform transection of all laterally perforating neurovascular bundles that supply the rectus muscle. (See "Overview of component separation", section on 'Blood vessels and nerves'.)

Transversus abdominis release (TAR) — At the lateral extent of a Rives-Stoppa retrorectus dissection, the posterior lamella of the IO can be divided just medial to the linea semilunaris, along with the underlying TA muscle, to enter the preperitoneal plane, which can be developed all the way into the retroperitoneum [3]. This modification allows for preservation of the lateral neurovascular bundles while still allowing for development of a wide retromuscular pocket. Division of the TA muscle conferred the name transversus abdominis release (TAR).

TAR has gained wide popularity not because it offers superior medialization of the rectus muscles compared with anterior component separation, but because TAR, in addition to allowing for equivalent myofascial relaxation to approximate the midline, creates a reproducible, well-vascularized, retromuscular pocket for mesh placement, all through a midline incision without the need for skin flaps [4]. Release of the posterior rectus sheaths allows for creation of a large peritoneal sac to isolate the viscera. With rare exception, this consistently allows for use of uncoated monofilament polypropylene, which is inexpensive and resilient to infection. (See "Overview of component separation", section on 'Facilitate retromuscular mesh placement'.)

RIVES-STOPPA RETRORECTUS DISSECTION

Incision and adhesiolysis

The abdomen is prepped and draped widely in a diamond shape to include the costal margin, lateral abdominal wall, and anterior superior iliac spine (ASIS). This is done to allow for transfascial mesh fixation with sutures.

A midline laparotomy is performed to include the patient's scar and extended cephalad at least 5 cm. After excising the superficial scar, the subcutaneous tissue is divided to a portion of the native linea alba above any of the patient's previous incisions. The native linea alba is divided to expose the underlying preperitoneal fat. At this point, the preperitoneal fat is sharply removed from the midline under direct visualization, including any viscera adherent to the midline scar or hernia sac until the intra-abdominal cavity is entered. Once the midline has been opened, visceral adhesions are freed from the entire abdominal wall using sharp dissection. Care must be taken during lateral adhesiolysis not to inadvertently enter the preperitoneal plane. Lysing interloop adhesions is preferable but not obligatory if the patient has no history or evidence of obstruction.

Once the viscera are completely free from the abdominal wall, a countable towel is placed over the viscera and tucked into each lateral pocket to keep the bowel isolated during the myofascial release. Of note, the towel will only be removed when the visceral sac is being closed, so it should not be placed unless the surgeon is happy with hemostasis and identifying any visceral injuries such as serosal tears. A missed enterotomy in this context can be catastrophic, and every measure of caution should be made to prevent this.

After placement of the towel over the viscera, the fascial defect is measured.

Division of posterior rectus sheath

Next, five Kocher clamps are placed on the medial edge of one rectus. Using a toothed forceps, the posterior rectus sheath is retracted and incised just lateral to the rectus edge to reveal the underlying muscle belly. Because hernia sac and/or a diastasis can distort the location of the rectus, its muscle belly should be palpated for confirmation and visualized after incision of the posterior sheath to confirm entry into the retrorectus space.

The entire medial edge of the posterior rectus sheath should be divided and the medial edge of the rectus muscle exposed. Place five additional Kocher clamps on the medial edge of the posterior rectus sheath.

Retrorectus dissection — Using firm but gentle traction on the anterior and posterior rectus sheaths, the retrorectus space is developed using cautery to control small epigastric perforators. The lateral extent of this space is marked by large neurovascular bundles and the deep inferior epigastric vessels, most notably at the inferior and superior aspects of this dissection before the vessels course into the rectus muscle belly. There is typically one large medial neurovascular perforator in the superior third of the retrorectus space that can be sacrificed, but the rest should be preserved if possible. The neurovascular bundles mark the lateral extent of the retrorectus space, and their protection prevents inadvertent division of the linea semilunaris, a devastating complication of this technique. Preoperative cross-sectional imaging should be used whenever possible to give the surgeon an idea of how wide the retrorectus space will be. (See "Overview of component separation", section on 'Retrorectus space'.)

At this point, if the posterior rectus sheath is sufficiently medialized toward the midline and a contralateral dissection will allow for isolation of the viscera, then a Rives-Stoppa dissection alone is sufficient. However, more often than not, continuation with a transversus abdominis release will allow for closure of the posterior components under less tension and a larger retromuscular pocket.

OPEN TRANSVERSUS ABDOMINIS RELEASE — Transversus abdominis release (TAR) is a versatile technique for repairing most large hernias. Traditionally, TAR was described for very large ventral hernias requiring anterior fascial advancement to reapproximate the rectus muscles. Given the many advantages of retromuscular mesh, it has now often been adopted for smaller hernias where a Rives-Stoppa dissection is inadequate to allow for posterior rectus sheath approximation. (See "Overview of component separation", section on 'Facilitate retromuscular mesh placement'.)

Several large series of TAR have demonstrated its efficacy and safety:

A large series of 428 TAR procedures revealed a modest wound morbidity rate of 18.7 percent, a low surgical site infection rate of 9.1 percent, and a very low mesh excision rate of 0.7 percent. One-year recurrence rates were reported to be 3.7 percent [5].

A systematic review including 646 TAR procedures likewise revealed a low surgical site occurrence rate of 15 percent, a surgical site infection rate of 7 percent, and a low recurrence rate at two years of 4 percent [6].

Another single-center series of 1203 TAR procedures with at least one-year follow-up (median two years) confirmed low rates of surgical site occurrence requiring procedural intervention (8.6 percent >1 year cumulative), long-term mesh excision (1.8 percent), as well as improvement in abdominal wall quality of life and decreased pain over time [7]. While the authors report an alarming composite hernia recurrence rate of 26 percent, this reflects a high rate of patient-reported bulging. Cumulative rates (>1 year) of radiographic (10 percent), clinical (9 percent), or recurrence requiring reoperation (3 percent) suggest that rates of clinically significant recurrence are more acceptable but not insignificant.

However, broadened usage of the TAR technique by those less familiar with the operation can lead to rare but devastating complications, such as linea semilunaris disruptions/transections [4]. (See "Overview of component separation", section on 'Linea semilunaris disruption'.)

Retrorectus dissection — A Rives-Stoppa retrorectus dissection is first performed as described above. (See 'Rives-Stoppa retrorectus dissection' above.)

Division of internal oblique and transversus abdominis muscles — The posterior lamella of the internal oblique (IO) and transversus abdominis (TA) muscle is divided just medial to the neurovascular bundles marking the linea semilunaris (movie 1). This dissection is aided by stiff traction on the posterior rectus sheath so that these layers are divided without detaching the underlying peritoneum. The superior third of the dissection is unique in that division of the posterior lamella of the IO reveals a large TA muscle belly that can be serially divided with a right angle clamp (figure 1). The inferior two-thirds of the dissection looks much different, and division of the posterior lamella of the IO and TA aponeurosis is often indiscernible. Both are divided to reveal the underlying peritoneum, and after the appropriate plane is entered, further dissection can be aided by a right angle clamp.

Lateral preperitoneal dissection

After division of the entire posterior lamella IO/TA complex, the posterior rectus sheath and contiguous lateral peritoneum can be bluntly separated from the TA muscle belly using a Kittner dissector. The peritoneum can become very thin during this lateral dissection, and large holes can be problematic, so every effort should be made to do this gently to keep the peritoneum as one continuous layer. Typically, there are thin fibers of transversalis fascia between the peritoneum and TA muscle belly, and these should be pushed away from the TA belly and kept with the peritoneum to make the peritoneal layer more substantial.

As the preperitoneal plane is developed laterally, the cephalad portion should be beneath the costal margin, and peritoneum will be peeled off the diaphragm, which interdigitates with the overlying TA muscle. Traveling under the costal margin gives reassurance that it is the correct plane, as intramuscular planes would insert anterior to the costal margin.

Caudad, the preperitoneal dissection can be carried into the retroperitoneum, where fat is encountered adjacent to the lateral quadratus lumborum. Peeling all of the fat off of the lateral quadratus muscle will lead to lumbar vessel bleeding. Rather, careful observation will reveal a cleavage plane between two retroperitoneal layers of fat, and following this plane leads to exposure of the underlying psoas muscle. This dissection can be challenging depending on the girth of the patient; palpation of the iliac vessels just medial to the psoas muscle can keep the surgeon oriented.

When there is a large hernia defect requiring the most significant posterior sheath advancement for visceral sac closure, developing the retroperitoneal plane along the entire length of the psoas muscle to the diaphragm will liberate the peritoneum as much as possible. For women, the round ligament will often be encountered and divided, and for men, the spermatic cord structures can be separated from the peritoneum as well.

Inferior preperitoneal dissection

Inferiorly, the preperitoneal plane below the arcuate line, contiguous with the posterior rectus sheath, can be developed into the space of Retzius, using caution to preserve the epigastric vessels. There is typically at least one large medial perforator here off the epigastric vessels that often needs to be divided.

The inferior preperitoneal plane should be developed inferiorly on one side until Cooper's ligament is exposed. Then, an identical dissection should be done on the contralateral side.

The two inferior dissections into the space of Retzius exposing Cooper's ligaments should be merged by bluntly sliding a finger from one Cooper's ligament to the other. If this is a virgin plane, the anterior tissue including the bladder can gently be swept down from the remaining anterior linea alba that has not been divided. If previous incisions have extended below the current laparotomy, any remaining tissue stuck anteriorly can be hooked by the finger from the aforementioned dissection and should be divided sharply under direct visualization, erring anteriorly to protect the bladder. This is a relatively avascular plane, and any bleeding should concern the surgeon that the bladder is close.

Superior preperitoneal dissection

Once the space of Retzius is cleared down to the pubis, the superior dissection is addressed. The preperitoneal dissection beneath the diaphragm must be merged with the retroxiphoid preperitoneal space. In order to do this, the posterior rectus sheath must be divided without disturbing the linea alba; this merges the lateral retrorectus space with the medial preperitoneal fat plane beneath the linea alba. Ultimately, the posterior rectus sheath will be entirely transected such that the lateral preperitoneal space afforded by the TAR dissection becomes continuous with the retroxiphoid preperitoneal fat.

To completely mature the retroxiphoid preperitoneal space to the central tendon of the diaphragm without disrupting the medial diaphragm, the retroxiphoid fat must be divided, heading posteriorly (rather than staying immediately on the xyphoid process) until the peritoneum itself is visualized. This will allow the peritoneum and only the peritoneum to be liberalized from the diaphragm without injuring the affiliated muscle until the central tendon is exposed.

Complete dissection of the lateral preperitoneal plane into the retroperitoneum to expose the psoas muscle as well as into the space of Retzius and retroxiphoid space to the central tendon of the diaphragm is not always necessary but is helpful when the defect is large or approaches a bony prominence.

Mesh placement and closure

Once the superior dissection is complete, the posterior rectus sheaths are closed with 2-0 braided absorbable suture to isolate the viscera, and any holes in the peritoneum are closed with 3-0 braided absorbable suture.

If the posterior rectus sheaths and associated peritoneum/preperitoneal fat cannot be reapproximated without undue tension to isolate the abdominal viscera, the underlying omentum should be utilized and circumferentially secured to the posterior sheath edge to patch whatever hole remains. In the rare situation where there is no remaining omentum, a piece of rapidly absorbable mesh should be used (eg, Vicryl).

Once the visceral sac is complete, we typically perform a transversus abdominis plane (TAP) block with 30 cc of 0.25% bupivacaine with epinephrine diluted to 60 cc with sterile saline, injecting 30 cc onto each side.

We then place a piece of uncoated monofilament polypropylene in the retrorectus space that is large enough to sufficiently fill the retromuscular pocket. Typically, we will utilize a piece of 30 x 30 cm heavyweight polypropylene for most clean cases. When a larger piece of mesh is required, we do have a 50 x 50 cm piece of medium-weight polypropylene. Medium-weight polypropylene is also preferred in the instance of Centers for Disease Control (CDC) class II/III wounds, including concomitant parastomal hernia repairs or patients with a higher risk of wound morbidity due to comorbidities or a history of surgical site infection.

A retromuscular mesh is then placed to fill the retromuscular pocket. Traditionally, the mesh was secured with transfascial fixation using eight separate #1 PDS sutures passed through the abdominal wall with a suture passer. In a randomized trial of 325 patients who underwent open retromuscular repair of a ventral hernia, one-year recurrence rate was similar with or without transfascial suture fixation of the mesh (7 versus 9 percent) [8]. Thus, for hernias <20 cm wide with anterior fascial closure, no mesh fixation is necessary. Mesh fixation with transfascial sutures is still reasonable for larger defects (>20 cm wide) or those without anterior fascial closure. If there is concern for insufficient overlap over bony prominences, the mesh can be directly secured to either Cooper ligaments, the xyphoid process, or the costal margin.

Most high-volume abdominal reconstructive surgeons perform TAR using extremely large pieces of mesh to fill the retromuscular pocket, mesh fixation, and TAP blocks, although such practices are not yet supported by high-level evidence.

Two No. 19 Blake drains are placed in the retromuscular pocket on either side before closing the anterior rectus sheath with either a running #1 PDS or, for cases of significant tension, interrupted figure-of-eight sutures.

Excess skin and hernia sac can be excised, and careful hemostasis should be confirmed in the subcutaneous space. An additional subcutaneous drain may also be placed.

The skin is closed in two layers with 3-0 monofilament rapidly absorbable suture followed by 4-0 monofilament absorbable suture. Skin glue is applied to the midline incision and stab incisions made for transfascial fixation.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Ventral hernia".)

SUMMARY AND RECOMMENDATIONS

Definitions – Component separation is a reconstructive technique that strategically divides myofascial layers of the abdominal wall in order to achieve tension-free midline fascial approximation. Posterior component separation techniques include the Rives-Stoppa retrorectus dissection and transversus abdominis release (TAR). (See 'Introduction' above and 'General principles' above.)

Rives-Stoppa retrorectus dissection – The Rives-Stoppa retrorectus dissection is initiated by medial division of the posterior rectus sheath. Laterally, it is typically limited by the semilunar line. (See 'Rives-Stoppa retrorectus dissection' above.)

Transverse abdominis release – The TAR builds upon the Rives-Stoppa retrorectus dissection by dividing the posterior lamella of the internal oblique and the transversus abdominis muscles just medial to the neurovascular bundles, which allows entry into the preperitoneal space. Once that space is fully developed laterally, inferiorly, and superiorly, the posterior rectus sheaths can be closed at the midline and a large mesh placed in the retrorectus space before the anterior rectus sheaths are closed. (See 'Open transversus abdominis release' above.)

Pitfalls – Posterior component separations (eg, TAR) should not be performed concomitantly with an anterior component separation, as this can significantly destabilize the abdominal wall and lead to permanent deformities. (See "Open anterior component separation techniques".)

Topic 130472 Version 5.0

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