Acellular Bovine Pericardial Patch for Difficult Abdominal Closure in the Pediatric Population: Our Experience with Review of Literature

ABSTRACT

Aims:

Closure of congenital body wall defects in children can be a challenging task for the pediatric Surgeon. Biological prosthesis has been increasingly used for high-risk wound closure in adult patients with excellent outcomes and use in the pediatric population has also been reported. Here, we aim to study the outcome of abdominal wound repair with a tissue-engineered acellular bovine pericardial patch.

Methods:

Over a period of 21 months, a total of 15 children had undergone abdominal wound repair with bioprostheses, i.e., bovine pericardial patch at our institute. Patient demographics, cause of defect, an indication of patch use, rate of infection, postoperative recovery, recurrence, and outcome were studied.

Results:

A total of 15 patients underwent abdominal wall closure with acellular bovine pericardial patch. Nine out of 15 patients were neonates, of whom five had gastroschisis, two had a congenital diaphragmatic hernia, and two had ruptured omphalocele major. Of the rest 6 patients, 2 were patients of bladder exstrophy, 2 were older children of congenital diaphragmatic hernia with incisional hernias, and 2 were older children with omphalocele major. Out of the five patients with gastroschisis, two died during the early postoperative period due to sepsis. The wound healed in the rest 13 patients with mild skin dehiscence in two patients. Only one child had a recurrence.

Conclusion:

Reconstruction with acellular bovine pericardial patch is a viable option in children with high-risk abdominal wounds as it allows tensionless repair with excellent healing and minimal complications. Recurrence, if any, may disappear with time as remodeling of the prosthesis occurs along with the growth of the body wall of the child.

INTRODUCTION

Reconstruction of abdominal wall defects in children presents a formidable challenge for pediatric surgeons. Whether dealing with congenital issues such as gastroschisis, omphalocele, or exstrophy, the loss of intra-abdominal space in congenital diaphragmatic hernias or postoperative wound dehiscence, traditional repair methods are often inadequate. The substantial size of these defects and the limited abdominal cavity in small children can lead to complications, including abdominal compartment syndrome and repair failure.

In young children, the use of autologous tissues, as seen in component separation techniques, is usually not feasible due to the delicate and fragile nature of tissues. Consequently, prosthetic patches have emerged as a viable solution. Initially, synthetic materials were employed for this purpose, but their high complication rates, including intra-abdominal adhesions, enterocutaneous fistulas when used in an inlay manner, and skin necrosis beneath thin skin flaps with minimal subcutaneous tissue, rendered them less favorable.[1] Over the past few decades, bioprosthesis, both allograft (human dermal matrix) and xenografts (porcine acellular dermal matrix, porcine small intestinal submucosa, and bovine pericardium collagen matrix), have gained popularity in reconstructive surgeries for both pediatric and adult population. These are purported to form a durable body wall and to resist infection through the ingrowth of the patient’s own tissue into the decellularized matrix.[2] This makes biological prosthetic materials indispensable for reconstructive procedures in pediatric patients, especially considering the inherent open wounds in conditions such as gastroschisis or ruptured omphaloceles, the immunocompromised state of newborns, and the rapid growth of children’s body walls.

We present our experience of using acellular bovine pericardial patch (SYNKROSCAFF; SynkroMax Biotech Pvt. Ltd., Chennai, TN, India) for abdominal wall reconstruction in neonatal and pediatric patients of gastroschisis, omphalocele, congenital diaphragmatic hernia, exstrophy, and burst abdomen.

METHODS

A retrospective review was conducted encompassing all patients who underwent abdominal wall reconstruction using a bovine pericardial patch in our department from January 2022 to September 2023. Institutional ethical clearance was obtained. The variables examined included patient demographics, diagnosis, defect type, associated anomalies, the presence of sepsis or intra-abdominal contamination, defect size, mesh dimensions, and its placement location. Postoperative complications, such as surgical site infections, skin necrosis, wound healing, ventilatory needs, signs of intra-abdominal hypertension, and hernia recurrence, were meticulously documented.

Data were entered and analyzed in Microsoft Excel. A descriptive analysis was done. The categorical variables were expressed with frequency and proportion, whereas the ordinal variable and numerical variable with nonnormal distribution such as age of the patient in days were expressed with a median. 95% confidence interval was used.

RESULTS

Over a 21-month period (January 2022–September 2023), our department performed abdominal wall reconstructions using bovine pericardial patches in 15 children (eight males and seven females). Among them, nine patients were neonates (aged 1–7 days), one was an infant, and the rest were aged between 1.5 years and 6 years (median age: 3 days). The median weight was 3.3 kg, with a range of 1.6 –15 kg [Table 1].

Table 1.

Demographic, clinical, and outcome data of all patients

Case	Age	Sex	Weight (kg)	Condition	Defect (cm)	Skin closure possible	Follow-up in months	Complication
1	1 day	Female	2.8	Gastroschisis	-	Yes	7	Skin dehiscence
2	2 days	Male	2.2	Gastroschisis	-	Yes	8	-
3	1 day	Female	1.8	Gastroschisis	-	Yes	-	Sepsis, death
4	1.5 days	Male	1.6	Gastroschisis	-	Yes	-	Sepsis, death
5	2 days	Male	2.1	Gastroschisis	-	Yes	3	-
6	2 days	Male	3.3	Ruptured omphalocele major	4×3	No	9	Scarring, bulge, recurrence
7	3 days	Male	2.9	Ruptured omphalocele major with ileal perforation	5×4	No	8	Scarring
8	4 years	Male	11	Omphalocele major with cardiac abnormality	10×7	Yes	2	Bulge
9	6 years	Female	15	Omphalocele major with cardiac abnormality	12×10	Yes	4	Bulge
10	2 years	Female	6	Repaired congenital diaphragmatic hernia with ventral hernia created during neonatal stage	8×6	Yes	5	-
11	1.5 years	Male	6	Repaired congenital diaphragmatic hernia with ventral hernia created during neonatal stage	7×5	Yes	19	-
12	2.5 days	Female	3.3	Congenital diaphragmatic hernia with difficult abdominal wound closure	-	Yes	15	-
13	7 days	Male	2.4	Congenital diaphragmatic hernia with burst abdomen and intestinal obstruction	2×4	Yes	20	Scarring, bulge
14	3 years	Female	14	Repaired exstrophy bladder undergoing rectal bladder creation	-	Yes	3	Scarring
15	7 months	Female	5	Burst abdomen in repaired bladder exstrophy complicated with varicella-zoster infection	8×7	Yes	7	Scarring

Indications for using the pericardial patch included congenital abdominal wall defects in nine patients (five with gastroschisis and four with omphaloceles), abdominal wall reconstruction for congenital diaphragmatic hernias in three patients, abdominal wound closure in redo surgery for exstrophy bladder in one patient, and repair of burst abdomen in two patients. The median follow-up duration was 8 months, ranging from 2 to 21 months.

Among the five patients with gastroschisis, all presented beyond 24 h of birth. Primary approximation of fascial edges was not feasible, necessitating inlay placement of the bovine pericardial patch for abdominal closure. None of the neonates required postoperative ventilatory support or showed signs of intra-abdominal hypertension. Unfortunately, two patients succumbed to sepsis unrelated to the prosthetic system on postoperative day (POD)-5 and POD-7. These two patients were excluded from the cohort for outcome assessment. Two neonates with ruptured omphalocele major underwent reconstruction with the patch. One of them had associated ileal perforation with fecal contamination. In both cases, skin cover was not possible, and collagen granules were used for dressing until epithelialization occurred. Two older children with omphalocele major and associated cardiac anomalies underwent patch reconstruction due to a loss of domain (defect size 10 cm × 7 cm and 12 cm × 10 cm, respectively). Both cases were successfully managed with inlay placement of the bovine pericardial patch. Three patients had congenital diaphragmatic hernias, with one being a neonate and two older children. The patch was used in an inlay manner to facilitate abdominal wall repair as primary fascial approximation was not possible due to significant loss of domain. One patient was a follow-up case of bladder exstrophy repair undergoing rectal bladder creation. Two patients underwent patch repair for burst abdomen: POD-5 of congenital diaphragmatic repair (defect: 2 cm × 4 cm) and POD-6 of bladder exstrophy repair complicated by varicella-zoster infection (defect: 8 cm × 7 cm) [Figure 1].

Figure 1.

Patient with burst abdomen after exstrophy bladder repair complicated by varicella-zoster infection. (a) Before burst abdomen repair. (b) Postoperative day 4 of repair with a bovine pericardial patch. (c) Wound at 7-month follow-up

In all patients, a single 4 cm × 4 cm sheet of bovine pericardial patch was used, except in the two older children of omphalocele major, in whom a single 8 cm × 8 cm patch was used. The sheets were used in the bridging inlay technique and sutured to the fascial edges with absorbable 3-0 polydioxanone suture (except in patients with burst abdomen after exstrophy repair, where the patch was sutured to the anterior bladder wall inferiorly). The patch could be covered by skin in all cases, except in two (2/15) neonates undergoing ruptured omphalocele repair. Intraoperatively, intragastric pressure and inspiratory pressures were checked after prosthesis placement. None of the patients received elective ventilation. Postoperatively, respiratory rate, oxygen saturation, urine output, and 12 hourly arterial blood gas (pH and pCO₂) were checked for the first 2 days. None of the patients required postoperative ventilatory support or showed any sign of intra-abdominal hypertension (intra-gastric pressure <10 cmH₂O). Three patients had an ongoing infection at the time of patch use (one case of fecal peritoneal contamination; one patient of burst abdomen after congenital diaphragmatic hernia repair; and one patient with generalized sepsis with varicella-zoster infection).

On follow-up, there was no feature of adhesive intestinal obstruction or bowel fistulization in any of the cases. The small area of dehiscence of overlying skin with associated mild skin infection was observed in only two patients (13%), which healed by secondary intention of conservative management [Figure 2]. There was no evidence of seroma formation or infection of the patch in any of the patients and none required removal of the prosthesis. Four patients had a visible bulge or protuberance in the area of prosthesis placement (31%); the size of which was observed to decrease in size on subsequent follow-up [Figure 3]. On ultrasonography, the patch appeared as a linear sheet-like echogenic structure in the operative site without any defect in the parietis. The underlying bowel loops were free from the patch/wall. Only one child of omphalocele operated during neonatal period had developed a ventral hernia which was discernible as a defect in the parietal wall (7%) [Figure 4]. Scarring that was seen in patients with burst abdomen or those who healed by secondary intention reduced with time, and the overall cosmetic result was satisfactory.

Figure 2.

Patient with gastroschisis. (a) Inlay patch placement. (b) Immediate postoperative. (c) Skin dehiscence at postoperative day 12. (d) Healed wound with scarring at 7-month follow-up

Figure 3.

Patient with burst abdomen repair with bovine pericardial patch (postoperative case of congenital diaphragmatic hernia). (a) At 2-month follow-up with visible bulge. (b) At 20-month follow-up with reduced size of the bulge

Figure 4.

Patient with ruptured omphalocele (repaired during the neonatal period) at 4-month follow-up with recurrence

DISCUSSION

Prosthetics are used in abdominal wall reconstruction for two purposes: reinforcement of weak musculature or addressing defects (acquired or congenital) that cannot be closed by approximating the fascial edges. Pediatric patients afflicted with conditions such as gastroschisis, omphalocele, congenital diaphragmatic hernia, exstrophy, or burst abdomen fall into the latter category. In neonates and small children, in addition to the defect itself, the surrounding tissues are thin, weak, and friable, making the technique of component separation using autologous flaps technically challenging. To address these defects, an ideal solution is a piece of tissue that can bridge the gap between the fascial edges while safely covering the underlying bowel and solid organs. This is where prosthetic materials play a crucial role.

Synthetic materials such as polypropylene, polytetrafluoroethylene (PTFE), polyester (Dacron), and composite PTFE are not preferable for inlay placement. Due to direct contact with the bowel or the presence of infection, a high incidence of intra-abdominal adhesion and enterocutaneous fistula formation has been noted with the use of these materials. There is also a higher rate of infection and graft rejection reported, particularly in small children and neonates who are inherently immunodeficient.[1] Absorbable synthetic materials such as polyglycolic acid though can be used for bridging fascial gaps, their low tensile strength, and associated high hernia recurrence rate, make them unsuitable for use.[3]

Biological prosthesis is prepared from decellularized human or animal (bovine or porcine) tissue (dermal/intestinal submucosal/pericardial). These provide a three-dimensional collagen scaffold for fibrovascular regeneration of native tissue. Because of excellent biocompatibility, nonantigenicity, and less inflammatory foreign-body reaction, these tissues cause negligible visceral adhesions.[1]

The bovine pericardial patch is acellular, essentially pure collagen matrix. It is fixed chemically, leading to increased strength, stability, reduced antigenicity, and long-term durability in clinical settings. It provides a natural microenvironment for host cell migration and proliferation, accelerating endothelialization and tissue regeneration. Having a structure autologous to the human extracellular matrix, it leads to seamless cell adhesion and integration into native tissue. It was initially engineered for use in cardiothoracic and vascular surgery for patch angioplasty, bioprosthetic valve replacement, etc., and has shown consistently good results.[4] The use of a bovine pericardial patch to repair abdominal hernias is now well established in adults and is considered a safe and efficient method for reconstruction of incisional hernias not suitable for direct repair.[5]

The ultimate goal of management of pediatric abdominal wall defects is closure with protection of the contents without increasing the intra-abdominal pressure and affecting the respiratory and hemodynamic functions. Silo, as a temporizing method of progressive reduction of viscera into the abdominal cavity, is frequently used in neonates with gastroschisis and omphalocele. While it can be a lifesaving procedure in most settings, it does require multiple attempts at reduction under general anesthesia, total parenteral nutrition, and ventilatory support. Due to the collection of serous fluid within the silo, there is also a very high rate of infection. Use of PTFE mesh and dual mesh (GORETEX; GORETEX dual mesh) for bridging the fascial gap has been reported as individual cases and limited series but is reported to have high rates of local infection and adhesive intestinal obstruction, leading to removal of the mesh. Even in the absence of infection, the mesh was removed in all cases to facilitate definitive reconstruction.[6,7,8,9] Component separation with or without tissue expanders and additional prosthetic reinforcement have been described in the pediatric population,[10,11] with good outcome and low recurrence rate. However, the available literature includes either single case reports or small cohorts (10 patients in one group and 7 patients in another) which include only three neonates. The rate of complications (infection, seroma, hematoma, skin necrosis, and recurrence) is also high in the reported case series (3/10 and 4/7, respectively).[12,13]

The invention of biological prosthesis and the advent of its use for body wall reconstruction was a definite milestone in the management of abdominal wall defects. In the setting of contamination, active infection, or inability of fascial closure, the use of biological prosthesis is now well established in adults. There are few reports of the use of biological prosthesis in pediatric patients, but most are cohort studies with small sample size, case reports, and descriptive series without long-term follow-up. ALLODERM (Human acellular dermal matrix) has been used in neonates with gastroschisis and omphaloceles,[14,15] without any report of infection and allowed early closure of defect. Although it was reported to have excellent short- and long-term results, it is expensive with restricted availability. Xenografts of the porcine source are mainly of two types, porcine acellular dermal collagen matrix (PERMACOL^™/STRATTICE^™) and porcine small intestinal submucosa (SURGISIS^™). The use of both has been reported in patients with gastroschisis, omphalocele, congenital diaphragmatic hernia, incisional hernia, and pediatric transplant recipients with comparable results in terms of infection, seroma formation, and recurrence.[16,17,18,19,20,21,22] In the series of 24 patients reconstructed with SURGISIS^™ reported by Naji et al., two developed recurrences, which resolved spontaneously at a 2-year follow-up.[20]

The other commercially available xenograft is the acellular bovine pericardium which we have used in our study. It is composed of a collagenous sheet with intertwined fibers, giving it mechanical strength and elasticity. The sheet is chemically treated to make it acellular and to remove antigenicity by removing proteins and proteoglycans. The bovine pericardial patch has been used extensively for various procedures in cardiothoracic and vascular surgery: patch angioplasty, valvuloplasty, repair of ventricular septal defect, etc., The complication rates (restenosis of vessels, suture line bleeding, and postoperative endocarditis) were reportedly lower with the use of bovine pericardium[4] when compared with other synthetic prostheses. It has also been used for the reconstruction of incisional hernias in adults and urological and gynecological surgeries. In literature, there are only four case series[23,24,25,26] and one case report[27] on bovine pericardium use in adult ventral hernia repair with contaminated or potentially contaminated fields. All these studies have reported very low rates of infection and relapse. Further, the relapse of the hernia was seen only after the inlay fixation of the prosthesis. In a comparative analysis of the use of synthetic mesh and bovine pericardium in complicated hernias, significantly less wound infection and recurrence were seen in bioprosthesis use.[28] Studies done on in vivo changes of the bovine pericardial patch in the body revealed early remodeling and excellent integration into the body wall. The patch was seen to maintain its structural integrity for a long duration with no antigenic reaction.[29]

Ours is the only study reporting the use of bovine pericardium in the pediatric population. In our series of 15 patients, only one child developed recurrence and two developed minor skin dehiscence. Two neonates with gastroschisis expired due to sepsis unrelated to the prosthetic system. None of the rest 13 patients required ventilatory support or showed hemodynamic instability in the postoperative period. Infection of the prosthesis system or any sign of adhesive intestinal obstruction was not seen in any patient. Patients in whom skin coverage was not possible, healed well by epithelialization. A bulge was noted in the area of prosthesis use in three children, but none had any fascial gap on imaging. The size of the bulge visibly reduced in size on follow-up. In the adult case series, more recurrence has been noted with inlay prosthesis placement when compared with the more acceptable sublay/onlay repair. However, in the pediatric age group, where direct fascial closure is not possible, inlay placement of this bioprosthesis may prove to be lifesaving in most cases.

In our present series, though none of the patients required removal of the prosthesis, questions remain about the strength, durability, and fate of the patch when used in growing tissues of children. Does the growth of the body wall lead to better tissue integration and eventually lead to a decrease in hernia recurrence with time? This might explain the spontaneous reduction in size of the remnant bulge in the growing children.

Limitations

Our study is a single-center retrospective analysis of a small group of patients with a short period of follow-up. In addition, the cohort includes patients with different disease processes. A longer follow-up is definitely desirable to study recurrences and long-term functional outcomes in growing children. A longer study duration will also address the concerns about the fate and requirement of removal of the prosthesis. Patients of similar disease processes will also better standardize the results. Finally, cost is a prohibitive factor, and the use of prosthesis is highly dependent on availability in resource-poor nations.

CONCLUSION

Although various techniques have been described, there is a lack of consensus regarding the management of pediatric abdominal wall defects. Biological prosthesis is now well established as an important armamentarium for ventral hernia repair in adults, particularly in an infected field. It can also be safely used in pediatric patients, including neonates, for tension-free abdominal wall reconstruction. Bovine pericardium has exhibited excellent healing and good functional and cosmetic results when used for bridging the fascial gap in pediatric abdominal wall defects. Although more data are required to standardize its use, it can definitely be a lifesaving tool in neonates and children with high-risk abdominal wounds with contamination and active infection.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.