Robotic Rectus Abdominis Harvest for Pelvic Reconstruction after Abdominoperineal Resection

Abstract

The use of robotic surgical systems to perform abdominoperineal resection (APR) has recently become more prevalent. This minimally invasive approach produces fewer scars and potentially less morbidity for the patient. The rectus abdominis muscle is often used for reconstruction after APR if primary closure is not feasible or the surgical site is at high risk of wound complications. Since the traditional open harvest of this flap creates large incisions that negate the advantages of minimally invasive APR, there has been growing interest in harvesting the rectus abdominis in a similarly robotic fashion. This article reviews the technique, benefits, and limitations of this robotic technique. Compared to the traditional open harvest, robotic harvest of the rectus abdominis leaves smaller scars, provides technical benefits for the surgeon, and offers possible morbidity benefits for the patient. These advantages should be weighed against the added expense and learning curve inherent to robotic surgery.

Background

Abdominoperineal resection (APR) involves extensive resection of pelvic organs and is typically performed in the management of advanced malignancies. ¹ While APR was traditionally performed as a large open procedure, there have been many advances in minimally invasive APR. This minimally invasive approach provides striking benefits with regard to incisional morbidity and postoperative scarring and is likely equivalent to traditional open resection from an oncologic perspective. ^{1 2} Robotic surgery has recently been introduced as a new approach in achieving minimally invasive APR. Developed over the past two decades, robotic surgery offers advantages of enhanced precision, tremor elimination, motion scaling, high resolution, and three-dimensional optics. ^{3 4 5 6} There have also been studies suggesting that robotic surgery results in less blood loss and transfusions, less pain, fewer infections, shorter hospital stays, less scarring, and a more rapid recovery and return to activities of daily living. ^{7 8 9}

If primary closure is not possible following APR or the surgical site is at high risk of wound complications, there are multiple options for reconstruction, including vertical rectus abdominis myocutaneous (VRAM) flap, gluteal flaps, gracilis flaps, and other lower extremity flaps. ¹⁰ The VRAM flap offers an easy reconstructive option in open APR cases, but it is less suited to minimally invasive APR given the extensive abdominal incision and dissection required for the flap. This extensive abdominal dissection is an unfortunate consequence of this procedure, especially after the preservation of these abdominal structures with minimally invasive APR. As a result, there has been a growing interest in using robotic surgery to harvest the rectus abdominis muscle. This article will discuss the technique, benefits, and limitations of robotic rectus flap harvest.

Technique

For robotic rectus muscle harvest, patients are positioned either supine or in the low lithotomy position with their legs in stirrups. A supraumbilical camera port may be placed for the APR procedure, but the camera should be repositioned for the rectus flap harvest. The ideal camera location for flap harvest is at the midpoint between the anterior superior iliac spine and the costal margin at the anterior axillary line. ¹¹ Two 8-mm instrument ports are placed, one on each side of the camera 1 to 2 cm (about 3 fingerbreadths) from the costal margin and iliac crest ( Fig. 1 ). ¹¹ If desired, ports may be placed more laterally to better visualize the edge of the rectus muscle. However, more lateral placement also brings the ports closer to the peritoneal reflection at the retroperitoneum; unnecessarily entering the retroperitoneum should be avoided as all required steps of the surgery take place in the abdominal cavity. ¹¹ Importantly, the ports should be placed on the side contralateral to the muscle being harvested. Insufflation is achieved in the standard fashion and the camera is swept to verify that the entire length of the rectus muscle and pedicle is visible and within easy reach. ¹¹

Fig. 1.

Illustration demonstrating port placement for robotic harvest of the rectus abdominis muscle.

The dissection begins by identifying the deep inferior epigastric (DIE) pedicle branching from the external iliac artery. The peritoneum is sharply opened and the DIE vessels are dissected out. If desired, indocyanine green angiography may be used to better visualize the vasculature. ¹²

The posterior rectus sheath lateral to the linea alba is then opened at the arcuate line. ¹³ The supraumbilical trocar used for the camera during APR serves as a useful landmark for this step. ¹² Next, the rectus muscle is dissected off the anterior rectus sheath along the avascular plane and between the tendinous insertions of the muscle. During this process, DIE perforators are identified and clipped, cauterized, or bipolared. Finally, the tendinous insertions can be released being careful to preserve the anterior sheath. ¹³ If the flap is to be used as an inferiorly based rectus flap for intra-abdominal pelvic reconstruction, the rectus muscle is divided cephalad as high as the costal margin and caudad between the pubic symphysis and the entry point of the pedicle into the muscle. A vessel sealer is recommended for this step to avoid hemorrhage from the superior epigastric artery contained within the muscle. ¹¹ After freeing the flap from its abdominal attachments, it may be inset into the pelvis. The coccygeal musculature provides a secure surface upon which to fasten the flap for pelvic reconstruction. The rectus flap may also be harvested as a superiorly based rectus muscle flap for mid-anterior chest wall reconstruction. To harvest the flap for this purpose, the muscle is divided caudally, turned over, and passed through an epigastric tunnel between the defect and the muscle. ¹¹ The rectus flap may also be used as a free flap by freeing the muscle from its caudad and cephalad attachments and dividing the pedicle. ¹¹ The isolated flap may then be removed in a gallbladder bag for inset at a new recipient site. ¹¹ Although prior ostomy placement may theoretically damage the flap pedicle, it has previously been shown that rectus flap harvest in a patient with prior ostomy placement can be successful if the pedicle can be proven to be patent. ¹⁴ The robotic surgical system allows for easy visualization of the pedicle for this purpose, and successful rectus flap harvest has been demonstrated in patients with a history of ostomy placement. ¹⁵

There is some debate in the literature regarding whether to harvest the posterior rectus sheath along with the rectus muscle. An advantage of harvesting the posterior sheath is that the added strength layer helps prevent splitting of the flap at any previously placed ostomy sites. This advantage may be particularly useful for rectus flaps harvested in a minimally invasive fashion, as these flaps have no skin paddle to provide added strength. ^{6 12 15 16} Additionally, the fascia of the posterior sheath provides a more secure tissue layer to hold sutures when insetting the flap into the pelvis. ^{6 12 15 16} This allows for reconstruction of the pelvic floor in a watertight fashion. ¹⁵

Whether the posterior rectus sheath is harvested or not, the surgeon must decide how to address the remaining posterior sheath after freeing the flap. The traditional belief is that the posterior sheath may be left open after flap harvest with low risk of hernia since the anterior rectus sheath remains intact. Thus, some authors have felt comfortable leaving the posterior rectus sheath open after robotic rectus muscle harvest. ¹¹ However, there are no outcome data rigorously investigating this risk, and some authors have reported routine closure of the rectus sheath. ¹³ Davila et al published their experience of leaving the posterior rectus sheath open in 10 patients with 2 of them developing a late hernia or bulge. ¹⁵ The authors suspected that fascial slits created by DIE perforators ultimately led to the hernias or bulge. Due to these complications, Davila et al began prophylactically reinforcing the posterior abdominal wall with biological mesh and running barbed suture. The authors have anecdotally noted no hernias or bulges in patients since making this change. ¹⁵

Benefits

Potential advantages of robotic harvest of the rectus abdominis muscle include aesthetic, technical, and morbidity benefits. The comparisons made in this section will be between robotic rectus abdominis muscle harvest and traditional open rectus abdominis harvest.

From an aesthetic perspective, robotic harvest leaves far smaller scars than those created by an open rectus harvest. This benefit is especially meaningful given that larger scars were purposely avoided by performing the initial APR surgery in a minimally invasive fashion. ¹¹

Robotic rectus harvest also offers many benefits over open rectus harvest from a technical perspective. The robotic system allows for a 3-dimensional anatomical view, tremor elimination, and motion scaling which facilitates easier and safer dissection. ^{6 16} The precision and visibility provided by the robotic system even allows for intraperitoneal flap anastomosis if required. ¹¹ Robotic dissection is also aided by gravity, which auto-retracts the flap as it is dissected from the abdominal wall. This phenomenon allows for easy visualization of perforators and tendinous and fascial insertions. ¹¹ Additionally, if desired, the surgeon may easily add indocyanine green angiography to better visualize vasculature. ^{6 16}

In addition to the technical and aesthetic advantages of robotic harvest, this technique may also offer morbidity benefits for patients. The traditional rectus abdominis harvest violates the anterior rectus sheath, putting patients at greater risk of abdominal bulge or hernia. ^{10 12} The overall rate of complications from open rectus muscle harvest may range as high as 8.5 to 14.3% due to complications such as hernias and bulges, superficial infection, partial skin loss, hematoma, and seromas. ^{17 18} In contrast, robotic harvest leaves the anterior rectus sheath layer intact, theoretically protecting patients from wound complications. ¹⁰ Additionally, damage to the anterior rectus sheath from the traditional open harvest eliminates potential future ostomy sites, although this point is less relevant in patients receiving rectus muscle harvest since surgeons are unlikely to place future ostomies in sites without underlying rectus muscle. While the literature has demonstrated the safety, effectiveness, and reproducibility of robotically harvested rectus muscle following APR, there have been few studies assessing surgical site morbidity. ^{13 16} Published studies report anecdotally observed reductions in postoperative pain and hospital stay and a more rapid functional recovery after robotic rectus harvest. ^{11 19} Haverland et al performed a retrospective review of six patients undergoing robotic rectus harvest and demonstrated favorable outcomes with shortened hospital stay in those cases. ¹⁶ This trend may be particularly important for patients receiving pelvic APR because these patients typically have multiple medical comorbidities. ²⁰ In another recent study, Davila et al compared use of robotic rectus abdominis muscle flaps to nonrobotic (traditional) techniques. ¹⁵ They noted no difference in surgical time or major complications, but did notice a reduction in minor complications such as surgical site dehiscence, cellulitis, or development of fluid collections in robotic cases. While rigorous, well-powered studies comparing complication rates between these procedures are certainly required, these initial findings suggest that robotic harvest may at least be noninferior to the traditional open harvest in terms of complications and may reduce morbidity secondary to large open incisions.

Comparison to Laparoscopy

An important comparison should also be made between robotic and laparoscopic rectus muscle harvest. Endoscopic/laparoscopic harvest of the posterior rectus sheath has traditionally been technically difficult and lengthy. ²¹ Moreover, early laparoscopic methods led to violation of the anterior rectus sheath with associated risks of hernia. ²¹ More recently, laparoscopic harvest has been done with an anterior-sheath-sparing technique; however, this technique has only been scarcely reported in the literature for use in perineal reconstruction. ^{22 23 24 25} With this sheath-sparing technique, laparoscopic harvest has many of the same advantages as robotic harvest, including potentially reduced incisional morbidity, enhanced recovery, decreased postoperative pain, and superior aesthetics. However, laparoscopy is not frequently taught in modern plastic surgery training, so laparoscopic rectus muscle harvest may present a technical challenge. ^{6 21} While robotic surgery training is similarly infrequent in plastic surgery, the intuitive, three-dimensional robotic interface flattens the learning curve and makes it easier to adopt compared to laparoscopy. ¹¹ Moreover, in the laparoscopic approach, insertion of instruments laterally along the abdominal wall requires the surgeon to aim upward at a steep and awkward angle. ⁶ Robotic surgery eliminates these issues with its interface and additional benefits of motion scaling and tremor elimination. ^{11 15} The multiple joints of robotic surgical devices minimizes or even eliminates the need for many challenging and awkward position encountered during laparoscopy.

It should be noted that there are very few reports directly comparing surgical time between robotic and laparoscopic surgeries. Some reports suggest that robotic surgery might have a slightly shorter harvest time (45 minutes) when compared to laparoscopy (60–90 minutes). However, this difference is small when compared to differences in surgical time and equipment setup secondary to variable surgical skill and experience. ^{6 21}

Limitations

The primary motivation for robotic harvest of the rectus muscle is to avoid violating the tissues superficial to the muscle. Therefore, the open musculocutaneous VRAM may be more suited when an additional large skin paddle is actually required for restoration of perineal skin, vaginal mucosa, and/or very large dead spaces. ^{6 19} Furthermore, while learning robotic surgery may be easier than learning laparoscopic surgery, there is still a learning curve associated with familiarization with the techniques, principles, and operation of robotic surgery devices. ^{26 27}

Another limitation of robotic harvest of the rectus muscle is cost. Based on prior analyses, robotic harvest is expected to cost an additional $1,000 compared to the traditional rectus muscle harvest. ²⁸ This cost may be substantial when compared with laparoscopy, which may cost only approximately $500 more than the traditional harvest. ²⁸ Physicians and patients should therefore carefully weigh the additional cost of robotic surgery against potential benefits. Rigorous cost–benefit analysis comparing robotic, laparoscopic, and traditional harvest is an important future direction of research.

Conclusion

Applications of robotic surgery have flourished over the past 20 years, requiring surgeons to assess the benefits and limitations of this new application in their respective specialties. Plastic surgeons have generally been slower to adopt laparoscopic and robotic techniques due to the nature of the specialty. While robotic surgery may not be beneficial in all reconstructive cases after APR, particularly if the initial APR was done in an open fashion, there appear to be many potential benefits of these techniques in select circumstances. Surgeons should also consider the added expense and learning curve that comes with robotic surgery; these concerns should be weighed against the technical benefits of robotic surgery and potential morbidity benefits for the patient. In general, in patients who have received robotic APR, completing the reconstruction in a similar robotic fashion may provide numerous technical and surgical benefits for both the surgeon and patient.

Funding Statement

Funding None.