Use of human acellular dermal matrix during classic bladder exstrophy repair

Acellular dermal matrix in reconstructive surgery: Applications, benefits, and cost

Modern tissue engineering has made substantial advancements that have revolutionized plastic surgery. Acellular dermal matrix (ADM) is an example that has gained considerable attention recently. ADM can be made from humans, bovines, or porcine tissues. ADM acts as a scaffold that incorporates into the recipient tissue. It is gradually infiltrated by fibroblasts and vascularized. Fortunately, many techniques have been used to remove cellular and antigenic components from ADM to minimize immune system rejection. ADM is made of collagen, fibronectin, elastin, laminin, glycosaminoglycans, and hyaluronic acid. It is used in critical wounds (e.g., diabetic wounds) to protect soft tissue and accelerate wound healing. It is also used in implant-based breast reconstruction surgery to improve aesthetic outcomes and reduce capsule contracture risk. ADM has also gained attention in abdominal and chest wall defects. Some studies have shown that ADM is associated with less erosion and infection in abdominal hernias than synthetic meshes. However, its higher cost prevents it from being commonly used in hernia repair. Also, using ADM in tendon repair (e.g., Achilles tendon) has been associated with increased stability and reduced rejection rate. Despite its advantages, ADM might result in complications such as hematoma, seroma, necrosis, and infection. Moreover, ADM is expensive, making it an unsuitable option for many patients. Finally, the literature on ADM is insufficient, and more research on the results of ADM usage in surgeries is needed. This article aims to review the literature regarding the application, Benefits, and costs of ADM in reconstructive surgery.

Dermal Matrices: Do We Always Know What Is Going On?

The use of dermal matrices in abdominal wall reconstruction has gained increased attention over time, particularly in contaminated fields. One of their advantages is the greater capacity to resist infection. We report a case of a 36-year-old man, with congenital bladder exstrophy and neobladder reconstruction during childhood. He presented to us with an abdominal hernia associated with a vesicocutaneous fistula. We used a bovine-derived dermal matrix (SurgiMend®, TEI Biosciences, MA, USA) for reinforcement of the abdominal repair considering its laboratory-proven mechanical superiority regarding strength. The early postoperative period was complicated by an infection that led to mesh disintegration and the need for surgical revision. We believe that matrix digestion by bacterial enzymes culminated in rapid breakdown of the product. Further investigations are warranted to determine optimal selection criteria and indications of bioprosthesis in contaminated wounds. Surgeons should be cautious when selecting a biologic mesh in these cases, favoring meshes with a better integration profile.

Clinical applications of acellular dermal matrices: A review

INTRODUCTION

The extracellular matrix (ECM) plays an integral role in wound healing. It provides both structure and growth factors that allow for the organised cell proliferation. Large or complex tissue defects may compromise host ECM, creating an environment that is unfavourable for the recovery of anatomical function and appearance. Acellular dermal matrices (ADMs) have been developed from a variety of sources, including human (HADM), porcine (PADM) and bovine (BADM), with multiple different processing protocols. The objective of this report is to provide an overview of current literature assessing the clinical utility of ADMs across a broad spectrum of applications.

METHODS

PubMed, MEDLINE, EMBASE, Scopus, Cochrane and Web of Science were searched using keywords 'acellular dermal matrix', 'acellular dermal matrices' and brand names for commercially available ADMs. Our search was limited to English language articles published from 1999 to 2020 and focused on clinical data.

RESULTS

A total of 2443 records underwent screening. After removing non-clinical studies and correspondence, 222 were assessed for eligibility. Of these, 170 were included in our synthesis of the literature. While the earliest ADMs were used in severe burn injuries, usage has expanded to a number of surgical subspecialties and procedures, including orthopaedic surgery (e.g. tendon and ligament reconstructions), otolaryngology, oral surgery (e.g. treating gingival recession), abdominal wall surgery (e.g. hernia repair), plastic surgery (e.g. breast reconstruction and penile augmentation), and chronic wounds (e.g. diabetic ulcers).

CONCLUSION

Our understanding of ADM's clinical utility continues to evolve. More research is needed to determine which ADM has the best outcomes for each clinical scenario.

LAY SUMMARY

Large or complex wounds present unique reconstructive and healing challenges. In normal healing, the extracellular matrix (ECM) provides both structural and growth factors that allow tissue to regenerate in an organised fashion to close the wound. In difficult or large soft-tissue defects, however, the ECM is often compromised. Acellular dermal matrix (ADM) products have been developed to mimic the benefits of host ECM, allowing for improved outcomes in a variety of clinical scenarios. This review summarises the current clinical evidence regarding commercially available ADMs in a wide variety of clinical contexts.

Acellular dermal matrix graft for ventral corporal lengthening orthoplasty in 2-stage proximal hypospadias repair

BACKGROUND

Correcting ventral curvature (VC) by lengthening the ventral corpora using a graft has been verified feasible, but still has been associated with the recurrence. The use of acellular dermal matrix (ADM) in the setting of tissue reconstruction has captured the attention of many surgeons. There are few reports on the use of ADM exclusively as correction of VC. Thus, we evaluate the safety and effectiveness of repairing the defect with ADM for straightening the VC in proximal hypospadias repair.

METHODS

We retrospectively analyzed the records of patients with proximal hypospadias who underwent ventral corporal lengthening with graft in staged repair from January 2013 to December 2019. Those with curvature greater than 30° after urethral plate transection were enrolled. ADM was used for repairing the defect left by transversely transection of tunica albuginea. Patient outcomes were compared with the non-matched control group who underwent the same procedure with tunica vaginalis (TV) repair. Patient demographics, operative techniques, complications, reoperations were summarized and compared between 2 groups.

RESULTS

Forty-three patients underwent ventral lengthening with ADM repair after transverse urethral plate transection and 35 patients with TV patching respectively. At a mean follow-up of 10 months in those with the first-stage ventral lengthening, 5 of 43 (11.6%) in ADM group was detected with recurrent VC, while 2 of 35 (5.7%) in TV group were observed with recurrent curvature contemporarily (P=0.363). At a mean follow-up of 46.8 and 45.3 months, persistent curvature in ADM group was not significantly different comparing to TV group (1/43, 2.3% vs. 1/35, 2.9%; P=0.883).

CONCLUSIONS

Ventral corporal lengthening using ADM graft may facilitate correction of VC without increasing the risk of urethroplasty complications. It offers a promising material that can be safe, effective and simple to use and provides psychological and aesthetic benefits. Additional series assessment and further randomized controlled trials will elucidate the clinical impact of using ADM with ventral lengthening.

Management and outcome in dehisced exstrophy with a simplified bladder re-closure and further reconstruction

INTRODUCTION

The traditionally accepted method of bladder re closure in dehisced exstrophy involves osteotomy assisted pubic bone approximation (PBA). Continent voluntary voiding is achieved in a small proportion of children sometimes after many operative procedures. We propose a simple yet reliable method of repair of the dehisced bladder using Rectus abdominis muscle flap (RAM) instead of PBA to bridge the inter-pubic gap, followed by concomitant or subsequent bladder augmentation (BA).

AIM

The aim of this study is to assess the outcome of dehisced exstrophy, using a RAM flap assisted redo closure (without PBA) with concomitant or subsequent further reconstruction.

MATERIALS AND METHODS

This is a retrospective analysis of children who presented with dehisced exstrophy after repair in other institutions and who have undergone redo repair using RAM flap in two tertiary care centers from 2001 to 2019. The outcome of the redo closure and subsequent or concomitant further reconstruction as regards dryness, stability of the upper tracts and resolution of vesico ureteric reflux (VUR) was studied.

RESULTS

Fifty five children (34 boys) underwent redo exstrophy repair for dehisced exstrophy using the RAM flap. Epispadias repair was performed concomitantly in 31 boys. In 26 children (group1) of mean age 12 months further surgery was deferred while in 29 children (group 2) of mean age 69 months underwent concomitant BA. Nine group 1 children underwent BA subsequently. Ureteric reimplantation was done at the time of BA in 54 ureters, 40 into the bladder plate and rest into the bowel segment of BA. 22 ureters were not reimplanted. Bladder neck surgery including 18 bladder neck closure and Mitrofanoff port for Clean Intermittent catheterization (CIC) were done along with BA. The RAM assisted bladder closure was event free and none needed redo operation. 35/38 augmented children are dry on Mitrofanoff CIC and one unaugmented boy voids normally. The upper tracts remain stable on ultrasound and VUR has resolved in 67/76 ureters. At current follow up, after a mean period of 53 months eGFR was normal in all except 3 who had initially presented with severe hydro uretero nephrosis.

CONCLUSION

We present a simple and reliable method of repair of dehisced exstrophy using RAM flap with the feasibility of concomitant BA. Dryness was achieved with stable upper tracts in 36/39 children, 27 of them with a single reconstructive attempt.

[Appllication of human acellular dermal matrix in surgical treatment of genitourinary disease]

Humanacellular dermal matrix (HADM) is widely used in the field of burn wound repair and tissue engineering plastic surgery. HADM is manufactored by physical and chemical decellular process to remove the antigenic components that might cause immune rejection in dermis.The extracellular matrix of three-dimensional cell scaffold structure with collagen fibers had been used for wound repair and tissue regeneration, while HADM characterized with low absorption rate after implantation and strong ability to induce angiogenesis in host tissue. Studies reported that after the HADM was implanted into the patient, the host cells, such as fibroblasts and myofibroblasts, as well as lymphocytes, macrophages, granulocytes and mast cells, rapidly infiltrated the graft. The connective tissue and neovascularization were then formed within the HADM three-dimensional cell scaffold, the lymphatic system also appears after vascular reconstruction. Traditional urethral reconstruction using autologous skin flaps has some defects, such as complexity of the technology, risk of necrosis of the skin flaps after transplantation, and failure to achieve functional repair of the urethral epithelium. It has been reported that using HADM to reconstruct the urethra in patients with urethral stricture, hypospadias and bladder-vaginal fistula, showed promising results. Others have reported the experience of using HADM to repair and reconstruct congenital classic bladder exstrophy. HADM has also been used for tissue repair in patients with penile skin defect caused by Fonier's gangrene and hidradenitis suppurativa, and implanted under Bucks' fascia to enlarge the penis. The report of HADM implantation for treating premature ejaculation also deserves attention. Researchers found that HADM implantation can form a tissue barrier between the skin and corpus cavernosum, which can effectively reduce penile sensitivity and treat premature ejaculation. The safety and effectiveness of HADM implantation in the treatment of premature ejaculation need to be further standardized by data from multi-center, large-sample clinical studies. In summary, HADM is the extracellular matrix and three-dimensional cell scaffold of human dermis. As a new type of tissue repair material, new blood vessels are formed actively after implantation, which shows good histocompatibility. HADM has shown increasingly broad application prospects in treatment of genitourinary diseases including penis, urethra and bladder diseases. HADM has also been used in the treatment of premature ejaculation in recent clinical studies, and its long-term safety and efficacy need to be further investigated.

Acellular dermal matrix contributes to epithelialization in patients with chronic sinusitis

BACKGROUND

Nasal endoscopic surgery is widely used for nasal diseases, including sinusitis and tumors. However, scar hyperplasia, nasal irritation, scab, and nasal obstruction delay nasal mucosal recovery, with prolonged cleaning exacerbating the patient's financial burden. Here, we presented a novel approach for the treatment of nasal mucosal defects, termed acellular dermal matrix.

METHODS

A total of 31 patients with bilateral chronic sinusitis (maxillary sinusitis and ethmoid sinusitis) underwent nasal surgery and nasal mucosal repair in September-October 2016. We divided the nasal cavities of each patient into control and acellular dermal matrix groups, randomly selected one side for nasal mucosal repair by surgery. A suitable acellular dermal matrix size was selected according to the defect in each patient. After pruning, the acellular dermal matrix was placed on the wound surface and filled with gelatin sponge. All patients were followed up for 14 weeks to compare nasal mucosal epithelialization between the control and acellular dermal matrix groups. Results：No obvious complications and adverse reactions were observed after nasal surgery. Lund-Kennedy scores in the acellular dermal matrix group were significantly decreased compared with the control group at 8 (0 (0, 1) vs. 2 (2, 4); P<0.05) weeks. Epithelialization time of eight weeks in the acellular dermal matrix groups was significantly decreased than the control group of 14 weeks.

CONCLUSION

Acellular dermal matrix provides a growth framework for the healthy mucosa on the wounded surface and reduces postoperative epithelialization time.

Challenges in salvaging urinary continence following failed bladder exstrophy repair in a developing country

INTRODUCTION

The management of urinary incontinence following failed bladder exstrophy repairs is not well defined, some surgeons recommend urinary diversion, others would pursue reconstructive surgery.

OBJECTIVE

Herein we review our experience with various strategies for management of urinary incontinence and their outcome in 61 patients born with bladder exstrophy who failed their initial repairs. We also examine the impact of diverse factors in making the surgical decision for patients with limited resources in a developing country.

MATERIAL AND METHODS

Between 1981 and 2014, 61 incontinent patients (age 3-18 years) born with bladder exstrophy were referred for secondary or tertiary repair. In nine children the bladder was exposed following wound dehiscence and 52 had had one or more attempted repairs resulting in contracted bladders. The primary treatment included: re-closure and bilateral iliac osteotomy in five patients (group 1); urinary diversion in Mainz II pouch in 15 patients (group 2); and 41 patients (group 3) underwent bladder augmentation and bladder neck reconstruction (31 patients) or bladder substitution and cystectomy (10 patients).

RESULTS

In group 1, three out of five patients were voiding with dry intervals. One child was dry between catheterization, and one was incontinent and underwent Mainz II diversion. All 16 patients with Mainz II pouch were continent of urine and stool. Of the 41 patients in group 3, follow-up was available for 34 patients, of whom 31 (91%) were dry between catheterization. However, additional surgery was performed in 15/34 (44%). Malignant changes were noted in 2/26 cystectomy specimens.

DISCUSSION

The quality of the bladder plate may deteriorate following failed bladder exstrophy surgeries. A few selected cases who had maintained a relatively healthy bladder plate were candidates for re-closure with osteotomy. Other surgical options included complex reconstruction with catheterizable channel, and internal urinary diversion. In this series the following factors were considered: a) pre-operative bladder biopsy to rule out pre-cancerous lesions, b) counseling the parents about possible additional surgeries after bladder augmentation or continent reservoir, and c) patients' geographic and socio-economic status.

CONCLUSIONS

Children born with bladder exstrophy are best treated at pediatric centers with expertise in their management. The exstrophied bladder should be protected and covered with non-adherent plastic wrap to prevent mucosal irritation and ulceration by the diaper. However, following failed surgeries the majority of incontinent patients can be salvaged to become continent/dry. It would appear that the Mainz II internal diversion offers a reasonable surgical option for selected patients, especially for females and those who have endured multiple surgical failures.