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Keywords:

  • Abdominal domain;
  • abdominal wall reconstruction;
  • acellular dermal allograft;
  • biologic mesh;
  • intestinal transplantation

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Disclosure
  8. References

Loss of abdominal domain is a common problem in intestinal transplantation. Several surgical options are available perioperatively for abdominal wall reconstruction. This study reports the management and complications for intestinal transplant patients with abdominal wall closure either primarily or with foreign material. This single center study reviews the records of intestinal transplant patients between 2004 and 2010. Study outcomes included reoperation for dehiscence, hernia or enterocutaneous fistula. There were 37 of 146 patients (25%) who required implantation of foreign material at transplant. Of these 37, 30 (81%) had implantation of acellular dermal allograft (ADA) and 7 (19%) implantation of another mesh. Perioperative dehiscence was rare with 2/109 (2%) for primary closure, 0/30 (0%) for ADA and 1/7 (14%) for other mesh. There were 12/146 (8%) patients who underwent ventral hernia repair: primary closure 7/109 (6%), ADA 3/30 (10%) and other mesh 2/7 (28%). There were 4/146 (3%) patients who required surgery for enterocutaneous fistulas: 2/109 (2%) primary closure, 1/30 (3%) ADA and 1/7 (14%) synthetic mesh. Abdominal wall reconstruction with ADA biologic mesh provides an expeditious means of performing a tension-free closure of the fascial layer after intestinal transplantation with complications similar to those seen for primary closure.


Abbreviations: 
ADA

acellular dermal allograft

ITx

isolated intestinal transplant

MMVT

modified multivisceral transplant

MVT

multivisceral transplant

PTFE

polytetrafluoroethylene

SPSS

statistical package for the social sciences

UCLA

University of California, Los Angeles

Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Disclosure
  8. References

Loss of abdominal domain is a frequent problem in intestinal transplantation (1,2). Most patients undergoing this type of transplant have a complex surgical history characterized by multiple operations and loss of intestinal length. This combination of factors can result in retraction of the abdominal wall with a loss of total volume in the peritoneal cavity. Inadequate abdominal space can be addressed at the time of intestinal transplant with choice of a proportionally smaller organ donor, graft reduction, primary closure with component separation techniques, fascia closure with mesh or other tissue or simultaneous transplantation of the donor abdominal wall or fascia (3–6). Choice of closure technique can be complicated by factors such as defect size, tension, intraoperative contamination and previous skin colonization or contamination (i.e. presence of previous ostomy, fistula or open wound). Abdominal wall complications can be associated with graft loss and patient death, though this association may only be a marker for increased patient complexity and risk (1,2,6).

Primary closure of the abdominal wall is preferred in most cases as it obviates the need for implantation of a foreign material. However, in the field of intestinal transplantation, the native fascia may be weakened by factors such as multiple operations, malnutrition, steroid use and tensioned closure. These factors may then lead to perioperative dehiscence, ventral hernia or exposure of the transplant intestine with subsequent fistula formation. Often, implantation of a foreign material is preferential to provide a nontensioned closure. Mesh reconstruction of the abdominal wall may consist of implantation of either permanent or nonpermanent material, from a variety of biologic and synthetic sources.

The Intestinal Transplant Program at Indiana University Health was started in 2003. Early in the history of this program, several options were explored for abdominal wall reconstruction including various types of surgical techniques, synthetic and biologic mesh, as well as differing donor sizes and graft reduction. Based upon clinical outcomes in the first 30–40 patients, the use of acellular dermal allograft became the preferred method of reconstruction, when required. This study reports the outcomes for a large number of intestinal transplant patients who have undergone abdominal wall closure with acellular dermal allograft (ADA). Primary outcomes for this study include reoperation for perioperative dehiscence, ventral hernia or enterocutaneous fistula.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Disclosure
  8. References

This single center study reviews the records of 146 consecutive intestinal transplant patients between 2004 and 2010. Both pediatric and adult patients were included. No patients were excluded. As some patients did not undergo formal closure of the abdominal wall at the time of transplant, abdominal wall closure was coded as the technique used for intended definitive closure. The abdominal wall closure for all patients was reviewed and categorized as primary fascial closure or closure with any foreign material. Mesh closures were with either ADA or other mesh material. A thorough chart review was performed to assess complications specifically related to fascia reconstruction including reoperation for perioperative dehiscence, hernia or enterocutaneous fistula at any time posttransplant.

Transplants included one of three types: isolated intestine transplant (ITx; intestine alone), modified multivisceral transplant (MMVT; stomach, duodenum, pancreas and small intestine) and multivisceral transplant (MVT; MMVT + liver). All patients received similar immunosuppression, which included induction with three doses of rabbit antithymocyte globulin, with each dose preceded by solumedrol (500, 250 and 120 mg) and a single dose of rituximab, and maintenance with tacrolimus and low dose steroids. Donor size was taken into account for all recipients, with goal donor size of 50–100% of recipient size to facilitate closure of the abdominal wall. Physical measurement of donor and recipient other than height and weight was rarely used in the size match decision.

ADA is derived from deceased donor human dermis. The dermis undergoes chemical processing to remove cellular components, leaving behind the tissue matrix. Research suggests that this tissue matrix allows revascularization of the dermis, thereby allowing blood components to migrate to the mesh. This vascularization permits implantation of this biologic mesh into an infected or contaminated field, unlike synthetic mesh. In this study, placement of thick and ultra thick ADA was per manufacturer's recommendation for preparation and implantation (AlloDerm, LifeCell, A KCI Company, Branchburg, NJ, USA). This material is commercially available in the USA, Canada, Korea, Mexico and Israel. Per a company representative, there is no current plan to expand distribution of this material because of limits on importation of human tissue. Because of the expense of this material, the mesh was often cut and shaped to fit the necessary space with the mesh sewn back together, as necessary. Typical defect size was 10–20 cm in greatest dimension and most defects could be covered by a 12 × 12 cm piece of ADA. The mesh was sewn into place with 0-prolene suture with moderate tension. It is recommended that this material be under moderate tension when placed as it loosens with time. ADA can stretch by up to 50% to cover larger and atypically configured defects. In the initial experience with ADA, we experienced rapid degradation of the mesh with direct exposure of the mesh to air (open wound) or to suction devices (closed suction or vac wound dressing). For this reason, we developed a policy of early return to the operating room to reclose any open skin wound, which resulted in exposed ADA. When the mesh remained covered with skin, we found that it retained its integrity indefinitely. Closure of the skin over the exposed mesh often included developing large vascularized skin flaps, with dermis closure using a combination of large vertical mattress sutures to reduce skin tension, as well as staples. Generally, a suction drain was placed over an area of native fascia in the subcutaneous space to prevent the accumulation of fluid and allow direct apposition of the skin to the mesh. When an open wound was reclosed, the incision site was routinely covered with a large bolster dressing of gauze, followed by an abdominal binder or compression dressing to encourage apposition of skin to mesh/fascia. In a limited number of cases, the mesh was removed after initial placement if postoperative edema resolved and primary closure was possible. These patients were considered to be primary closure for this study. Wound infections were managed by opening the wound and draining infected fluid. All open wounds were considered to be colonized and wound cultures were not routinely obtained. In patients with mesh, Aquacell Ag Hydrofiber (ConvaTec, Incorporated, Skillman, NJ, USA), a moisture retaining material impregnated with ionic silver, was placed over the mesh to treat infection and to prevent desiccation, with gauze dressing changed twice daily over the Aquacell. Intravenous antibiotics, as indicated, were administered until the wound was clean, without cellulitis and the patient was afebrile without leukocytosis. When the wound was clean and healing, the patient was returned to the operating room for delayed primary closure. Porcine derived mesh was used in a limited number of patients, but it was found to degrade and it was technically more difficult to implant because it is not pliable.

Standard statistical testing was conducted using commercially available software (IBM SPSS Statistics, Version19; IBM, Armonk, NY, USA). Categorical variables were compared using chi-square testing, though most numbers were too small for statistical analysis. Retrospective analysis of data using the transplant research database at our center has been reviewed and approved by the institutional review board of the Indiana University School of Medicine.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Disclosure
  8. References

The majority of patients in the series were adults (n = 113, 77%). ADA was implanted into 22 adults and 8 pediatric patients, which was proportionally similar to the transplanted population, though a greater percentage of the pediatric population received some other mesh (p = 0.06). The type of abdominal wall closure did not differ by transplant type (p = 0.26; Table 1). Pediatric patients requiring abdominal wall reconstruction had undergone multiple surgeries for common issues such as gastroschisis, malrotation with volvulus and jejunal atresia. Adult patients were more likely to have had chronic disease states over several years such as Crohn's disease, desmoid tumors, trauma (with open abdomen) and surgical complications with internal and enterocutaneous fistulas.

There were 37 of 146 patients (25%) who required implantation of a foreign material for fascial closure at the time of transplant (109/146 primary repair [75%]). Of these 37, 30 (81%) had implantation of ADA and 7 (19%) received implantation of another mesh (vicryl, prolene or donor fascia). Perioperative dehiscence was rare with 2/109 (2%) in the primary closure group, 0/30 (0%) in the ADA group and 1/7 (14%) in the other mesh group. Ventral hernias were only repaired if they were symptomatic which is not common postintestinal transplant due to the formation of dense adhesions. There were 12/146 (8%) patients that underwent ventral hernia repair. The incidence of hernia by repair type was: primary closure 7/109 (6%), ADA 3/30 (10%) and other mesh 2/7 (28%). There were 15/146 (10%) of patients who required surgery for fistula, 4 enterocutaneous and 11 gastrocutaneous (gastrostomy tube site). For the 4 enterocutaneous fistulas, closures included: 2/109 (2%) primary closure, 1/30 (3%) ADA and 1/7 (14%) synthetic mesh. A series of pictures are included in Figures 1 and 2, documenting the procedure, abdominal wall defect, implantation of the ADA and final closure.

image

Figure 1. Adult patient requiring complex abdominal wall reconstruction: (A) fascial defect with partial closure of lower midline incision, (B) implantation of acellular dermal allograft.

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image

Figure 2. Pediatric patient requiring complex abdominal wall reconstruction: (A) before transplantation of the multivisceral graft, (B) fascial defect with partial closure of upper and lower midline incision, (C) implantation of acellular dermal allograft and (D) final wound closure.

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Wound related complications are listed in Table 2. The risk of any posttransplant intraperitoneal operation was common (46% overall, range 43–57%). Of the 47 patients closed primarily who underwent subsequent surgery, seven received ADA implantation (15%). Wound debridement and reclosure of the skin was most common in the ADA group (30%). There was an aggressive management of the wound in the ADA patients after it became clear that the ADA required skin coverage to prevent mesh degradation. In some patients, the skin was reclosed multiple times and in three patients on warfarin therapy, there was requirement for hematoma evacuation. Wound infections were common (22% overall), but were less common in patients closed primarily without mesh (range 18–40%).

Table 2. Clinical complications stratified by type of abdominal wall closure
 OverallPrimary repairAcellular Dermal allograftOther mesh1
  1. 1Other meshes included vicryl, polypropylene (prolene), permacol (porcine) and donor fascia.

  2. 2Symptomatic ventral hernias requiring operative repair.

  3. 3There were 11 gastrocutaneous fistulas requiring repair (related to gastrostomy tube).

Number146 (100%)109 (75%)30 (20%)7 (5%)
Dehiscence3/146 (2%)2/109 (2%)0/30 (0%)1/7 (14%)
Ventral hernia212/146 (8%)7/109 (6%)3/30 (10%)2/7 (28%)
Enterocutaneous4/146 (3%)2/109 (2%)1/30 (3%)1/7 (14%)
Fistula3    
Posttransplant abdominal wall or wound-related surgery
 Any posttransplant reoperation67/146 (46%)47/1 09 (43%)16/30 (53%)4/7 (57%)
 Requiring abdominal wall closure    
 Wound debridement/skin closure16/146 (11%)6/109 (5%)9/30 (30%)1/7 (14%)
 Evacuation of hematoma7/146 (5%)4/109 (3%)3/30 (10%)0/7 (0%)
 Skin graft3/146 (2%)0/109 (0%)1/30 (3%)2/7 (28%)
 Mesh/wound infection33/146 (22%)19/109 (18%)12/30 (40%)2/7 (28%)
Postoperative clinical outcomes (days, median)
 Length of hospital stay37344749
 Length of intensive care unit stay88107
 Number of days on ventilator2247

With a median follow-up of 30 months, there were 48 patient deaths (33%). The number of deaths did not differ by abdominal closure study group: primary closure n = 37 (34%), ADA n = 7 (24%) and other mesh n = 4 (57%) (p = 0.23). Length of stay is reported in Table 2 and was longer in patients requiring mesh implantation. This is not unexpected as these patients were often more surgically complex when compared to primary closure patients. There were no graft losses related to abdominal wall complications. There was one patient death linked to abdominal wall closure. The death was a 52-year-old female who underwent isolated intestinal transplant and was closed primarily. She developed complications of abdominal compartment syndrome including renal failure, respiratory failure and severely elevated liver enzymes. She returned to the operating room on postoperative day 1 for placement of ADA and was found to have severe liver congestion and necrosis. In spite of presumed previously normal liver function, the patient developed ongoing liver failure, likely related to necrosis, never left the intensive care unit and died 85 days posttransplant of liver failure.

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Disclosure
  8. References

Several previous studies have addressed the issue of abdominal wall reconstruction after intestinal transplantation. No previous studies have reviewed a large number of patients with ADA closure. This study reports a large experience with biologic mesh use in intestinal transplantation in conjunction with other techniques including minimization of edema (avoidance of over resuscitation), graft reduction (including liver and small intestine), use of small donors and splenectomy.

Abdominal wall reconstruction with ADA provides an expeditious means of performing a tension-free closure of the fascial layer after intestinal transplantation. In this study, complications associated with use of this material are similar to those seen with primary closure of the fascia, but much lower than those seen with other types of mesh. There are many benefits to the use of this material in intestinal transplantation. First, biologic mesh is readily available and does not require extensive effort to prepare and implant such as that required for donor fascia or deceased donor abdominal wall. Second, this material can be placed into an infected or contaminated field, which is frequently seen in these complex and lengthy cases. In this series, no ADA was removed because of graft infection. Unlike other biologic meshes, ADA is very pliable, which makes it easy to work with, and this material technically conforms more easily to the defect that is being repaired. Also, this pliability reduces the risk of increased intraabdominal pressure and, in our series, there were no cases of abdominal compartment syndrome in patients with ADA. Additionally, in our series, we utilized graft reduction for limited space in less than five cases, allowing us to maintain full intestinal length in most cases. With a less tensioned fascial closure, patients with ADA may experience less postoperative pain, though that outcome was not specifically assessed in this study.

In our experience, successful use of ADA requires aggressive interventions to achieve and maintain skin coverage over the mesh, and to avoid use of suction devices (drains/wound vac) directly over the mesh. We did see mesh degradation when skin coverage was not maintained. Also, placement of ADA in most patients will result in development of a large potential space between the fascia and skin. In all cases, our practice was to place a suction drain in this space for an extended period of time (daily drainage < 10 cc) to encourage apposition of the skin to the mesh. However, the drain must be placed over native fascia or the force of the suction will erode ADA. ADA is much more expensive than other options for abdominal wall closure. For most of our patients who received ADA, the cost for the implanted mesh ranged from $5000 to $10 000 depending on mesh size. This cost must be balanced against the costs associated with abdominal wall complications such as prolonged length of hospital stay, wound care and multiple reoperations.

There are other options for implantation of foreign materials. Donor fascia carries no additional costs, other than the time required for preparation. Most synthetic meshes are less expensive than biologic mesh and do not degrade with time. However, these materials are subject to infection and frequently form dense adhesions. In a 2007 paper from UCLA, 14 of 28 patients could not be closed primarily after intestinal transplantation. Seven of these 14 underwent final abdominal wall closure with synthetic polytetrafluoroethylene (PTFE; Gore-Tex) mesh and all seven died before discharge from the hospital (1). A 2000 paper from Miami reports implantation of PTFE mesh, which was reduced in size in serial operations in 7 of 15 patients, but this study reports that the majority of patients died before final closure (2). Finally, a 2008 paper from Bologna reports primary closure in 60% of 38 patients, with synthetic mesh implantation in four patients. Among these four patients, all four developed mesh infection (100%) and two developed enterocutaneous fistulae (50%), with one of these two patients dying (6).

In conclusion, our center has experienced good success with use of ADA in abdominal wall reconstruction after intestinal transplantation. This includes use in both adult and pediatric patients in a variety of complex intestine and multiorgan transplants. Complications with use of this material are similar to those for primary closure and avoid certain posttransplant issues such as abdominal compartment syndrome and staged mesh reduction for definitive closure.

Disclosure

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Disclosure
  8. References

No commercial organization was involved, in whole or in part, in the funding of this study or in preparation of the manuscript. The authors of this manuscript have no conflicts of interest to disclose as described by the American Journal of Transplantation.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Disclosure
  8. References