Abdominal Wall Reconstruction



Abdominal Wall Reconstruction


Daniel J. Park

S. Alexander Earle



Abdominal wall defects and ventral hernias are common complaints that bring patients to seek surgical attention. In addition to primary defects, studies have shown that about 20% of laparotomies will result in incisional hernias. Patients present with a variety of complaints ranging from asymptomatic bulges to obstructive symptoms with significant limitations on quality of life. With 10-year failure rates of primary suture repair well over 60% (and greater than 30% for mesh repair), this is clearly an area for improvement. Recent investigations, as well as innovative techniques and materials, have sought to improve outcomes. We present our approach to the treatment and management of abdominal wall reconstruction.




PREOPERATIVE PLANNING

Diagnosis can usually be made through a thorough history and physical examination. Often, the defects and any herniating contents are obvious on cursory examination. Imaging with an abdominal computed tomography (CT) can be helpful with more subtle defects, and also in the acute setting, to determine the extent of the defect, presence of multiple defects (“chain of lakes”), and the presence of herniated organs. Evaluation also includes laboratory evaluation and perioperative risk evaluation.

Proper patient selection is crucial in the elective setting, more to optimize potential outcomes rather than to avoid difficult surgery. Even in high-risk patients, repair has been shown to provide a significantly improved quality of life. But as stated before, the high-potential failure rate makes it imperative to identify and address modifiable risk factors preoperatively to provide a lasting and durable repair. These risk factors commonly include ascites, obesity, diabetes, chronic obstructive
pulmonary disease (COPD), and smoking. Every attempt should be made to intervene and to optimize comorbidity before surgery.

Patients with ascites are at particular risk of recurrence and wound complications, leading to poor outcomes. Ascites can lead not only to wound complications but also to subsequent bacterial peritonitis as well as significant morbidity and possible mortality. Medical evaluation is imperative, and therapy to manage the ascites is crucial to favorable outcomes.

Obesity has been shown to be associated with increased wound-healing complications, as well as being a cause for recurrence. If asymptomatic, patients should be encouraged to lose weight through lifestyle modifications, including diet and exercise. Weight loss is not always possible because the abdominal wall defect can often make activity and exercise difficult or near impossible for patients. As such, potential benefits of repair, such as improved activities of daily living need to be balanced against potential weight-related complications. Diabetes is a frequent comorbidity that may exist in the obese patient and is also associated with significant wound-healing complications. Comorbidity risk may improve with weight loss and exercise, but medical evaluation should be performed to optimize glycemic control to limit possible complications.

Smoking and the presence of COPD are risk factors affecting both healing and possible recurrence. Smoking cessation is very important because the vasoconstriction secondary to nicotine and other products of smoking can significantly impair wound healing. This caveat is especially true in patients undergoing component separation, where perforators to the skin flaps are disrupted and circulation can be compromised. The added insult of smoking greatly increases the chances for skin edge ischemia. COPD can increase the chances of recurrence because of the repetitive significant increases in intra-abdominal pressure with coughing.


SURGERY


Techniques

The approach to repairing abdominal wall defects should be similar to those of other reconstructive problems elsewhere in the body. When considering these problems, the idea of the “reconstructive ladder” can be a helpful guiding principle in choosing the appropriate method of reconstruction. The simplest method for repair would involve primary repair of the abdominal wall defect. The goal of any repair is twofold: restoration of a functional abdominal wall by centralizing the rectus muscles, providing more normal vectors of force, in addition to restoring form by eliminating bulging due to hernias.

The first step in all cases is defining the abdominal wall defect. It is often difficult to dissect the hernia sac completely from the surrounding tissues and reduce the contents into the abdomen. These often long-standing defects have a significant amount of surrounding fibrosis and scarring between the sac and the adjacent soft tissue. The safest method involves opening up the hernia sac, reducing the contents after careful lysis of adhesions, and debriding the sac and any scar tissue off of the fascial edges. For patients with prior repair and mesh placement, this can be difficult and time consuming but is worth the effort to provide better tissue to sew to and reduce possibly colonized material left in the wound. The size of the defect and whether the fascial edges can be approximated will determine the reconstructive methods used to close the defect (Table 65-1).


Simple Primary Midline Defects

For simple defects with easily approximated fascial edges, primary closure can be attempted. As described previously, simple primary closure is associated with very high recurrence rates and should rarely be attempted except in very small defects. It is our practice to perform primary repair in defects 2-3 cm in diameter or less, using a large, slowly absorbing, monofilament suture in a running manner. There is debate whether the type of suture or particular method of repair, including permanent versus absorbable, monofilament versus braided, interrupted versus continuous affects recurrence rates. Most studies have shown that those factors are unimportant. The most important factor in successful, durable repair is careful tissue handling with precise placement of sutures 5 mm from the fascial edge with 5-mm travel between subsequent sutures. The decision whether to use running or interrupted sutures is surgeon dependent.


Medium-sized Midline Defects

For larger defects with fascial edges that can still be approximated in the midline, we combine primary repair of the fascia with mesh reinforcement. There are several issues that must be considered
when deciding on which mesh to use in a particular patient. The materials available for abdominal wall reconstruction are vast, and a brief description is warranted.








TABLE 65-1 Abdominal Wall Reconstruction Techniques













































Technique


Advantages


Disadvantages


Expected recurrence rate


Comments


Primary repair (“ standard” suture technique)




  • Familiarity



  • Uncomplicated unless there is a large defect




  • High failure rate



  • Increased wound infection rate


60%


Technique should be abandoned


Primary repair (“short suture” technique)




  • Increased wound strength



  • Lower wound infection rate



  • Lower recurrence rate?




  • Unfamiliar technique



  • Increased operative time


Unknown, but probably <60%


Should be used for closure of all laparotomy wounds


Prosthetic repair (“inlay” technique; edge of mesh sutured near edge of the defect)




  • Technically simple




  • High failure rate



  • Prosthetic becomes exposed if wound is opened


60%


Technique should be abandoned


Prosthetic repair (“sublay” or intraperitoneal technique)




  • Lower recurrence rate



  • Prosthetic not exposed if wound is opened



  • Better tolerance of infection even if prosthetic is involved (sublay only)



  • Does not require complete closure of midline




  • Technically more difficult


5-10%


Sublay technique may require prosthetics designed for intraperitoneal use if posterior layer cannot be closed


Prosthetic repair (“onlay” technique)




  • Technically easier than retromuscular techniques




  • Requires complete closure of midline



  • Requires skin flaps



  • Prosthetic becomes exposed if wound is opened


Unknown, probably around 15%


In general, prosthetics designed for intraperitoneal use are not required


Component separation technique




  • Able to close midline defects up to 20 cm in width



  • May be used with the prosthetic technique (retromuscular or onlay)




  • Requires some training



  • Increases operative time




  • 20-30% if midline is closed using “standard” suturing technique



  • Probably 10-20% if “short suture” technique is utilized



  • Probably 10% if utilized with “short suture” technique and a prosthetic


Standard open component separation associated with 20-30% major wound complication rate; endoscopic or may need open techniques to lower wound complication rates by avoiding large skin flaps to disrupt blood supply

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May 5, 2019 | Posted by in GENERAL | Comments Off on Abdominal Wall Reconstruction
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