A comparison of free skin graft, fascia lata, alloderm, bovine pericardium and primary repair in urethrocutaneous fistulas without diversion: an experimental study

Human umbilical cord allograft associated with higher pediatric urethrocutaneous fistula repair success rates

BACKGROUND

Urethrocutaneous fistula (UCF) formation is a known complication following hypospadias repair, affecting between 5 and 70% of cases. Moreover, approximately 30% of patients experience refistulization after UCF repair. The use of extracellular matrices, such as AmnioCord, a dehydrated human umbilical cord allograft manufactured by MiMedx®, may mitigate high rates of refistulization.

OBJECTIVE

To determine whether the use of AmnioCord during UCF repair is associated with reduced incidence of subsequent UCFs among pediatric patients.

DESIGN, SETTING, AND PARTICIPANTS

Electronic medical records were retrospectively reviewed among 60 patients who underwent at least one UCF repair at a pediatric hospital in a large urban setting in the U.S. between January 2012-June 2018. Patients were followed through January 2024.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Adjusted generalized estimating equation regression models were used to assess the association between AmnioCord use and rates of refistulization, while controlling for confounding variables.

RESULTS

The number of fistula presentations per patient ranged from one to four; 53.3% had one fistula, 30.0% had two, and 16.6% had three or more. Overall fistula repair success rate was 56.8% but significantly differed by AmnioCord use in adjusted modelling; 69.4% of cases that received AmnioCord were successfully repaired, compared to 47.2% of cases that did not receive AmnioCord. In adjusted models, patients who received AmnioCord had 2.66 times greater odds of surgical success than patients who did not receive AmnioCord (95% CI:1.13-6.24; p = 0.02).

CONCLUSIONS

This study demonstrates a positive association between AmnioCord use and successful UCF closure among pediatric patients.

Promising results for hypospadias repair using alloderm® (Regen): A randomized controlled trial

INTRODUCTION;: Hypospadias is a congenital disorder of urethra in which meatus is not at its correct place and occurs in 1 of 250 live male birth. Many techniques have been used for the repair of hypospadias and to decrease the incidence of fistula. Alloderm has been recently used for the repair of urologic congenital defects, and reconstructive surgeries, but not used in hypospadias in a randomized controlled trial. Therefore, the aim of this study was to assess the efficacy of Alloderm® (Regen) to reduce fistula rate in hypospadias repair.

METHODS & MATERIALS

This was a randomized controlled trial. Sixty patients were divided into two groups, 30 children underwent surgery using Alloderm® (Regen) as the Alloderm group and 30 without using it as controls. In the Alloderm group, 21 underwent primary surgery (12 mid-shaft hypospadias who underwent concurrent chordee correction and urethroplasty, and 9 penoscrotal who underwent 2 stage surgery, chordee was first corrected and then 6 months later TIP was performed), and 9 underwent fistula repair due to previous surgeries. In the control group, 24 patients underwent primary surgery (15 mid-shaft, and 9 penoscrotal) and 6 fistula repair the same as the Alloderm group but without using Alloderm.

RESULTS

There was no meaningful difference between the two groups regarding age (P = 0.634). There was no meaningful difference regarding the operation type between the two groups (P = 0.371). There was no meaningful difference regarding the meatal location between the two groups (P = 0.781). There were no significant post-operative complications in the both groups. No bleeding or diverticulum occurred. Recurrence of fistula occurred in one patient in the Alloderm group after fistula repair and in 2 in the control group. Overall, In the Alloderm group, 3 (2 after TIP and 1 after fistula repair) patients and in the control group 8 (6 after TIP, 2 after fistula repair) patients developed fistulas after surgery (10% vs 26.7%). There was a statistically meaningful difference regarding fistula formation between the two groups using Chi-square test (P = 0.014).

CONCLUSION

Alloderm® (Regen) can be used for hypospadias and fistula repair with very few complications and good results. Fistula was less probably occurred in the Alloderm group compared to the standard repair of hypospadias.

Use of fascia lata autograft for repair of urinary bladder defect in rabbits

The aim of this study was to investigate the compatibility of a fascia lata autograft for urinary bladder tissue defect, to evaluate the biomechanical, radiographical, macroscopical, biochemical, and histopathological test findings, and early and late complications of the surgical processes in rabbits. Thirty two adult healthy New Zealand rabbits were randomly allocated to 4 different groups of 8 animals. A 2 × 2 cm urinary bladder defect was repaired by the same size of fascia lata in experimental groups (Group 1, 2, 3). Rabbits in Group 1, 2 and 3 were euthanized at the end of the 4th, 8thand 12thweek after surgeries, respectively. No surgical procedure was carried out for the urinary bladder of the rabbits in the control group, but their urinary bladders were used for biomechanical tests and the values compared with those of Group 1, 2 and 3. Histopathological examination of the grafted area was performed. The grafted area was consistent with that of the tissue of urinary bladder. No significant difference was found between the urinary bladder and the grafted area. No differences in biomechanical tests were recorded between grafted and ungrafted urinary bladders. Histopathologically, fascia lata turned into a normal urinary bladder tissue. Therefore, a fascia lata autograft can be succesfully used in urinary bladder defects. Fascia lata grafts can be used successfully in pathological conditions of the urinary bladder that require a new tissue.

Fistula tract curettage and the use of biological dermal plugs improve high transsphincteric fistula healing in an animal model

PURPOSE

The treatment of high transsphincteric fistula is a complex procedure, which may be associated with the risk of recurrence and fecal incontinence. In this study, we used an animal model to compare different types of sphincter-preserving treatments for transsphincteric fistula.

METHODS

Sixteen female New Zealand rabbits, weighing 2.8-4.8 kg underwent a surgical creation of high transsphincteric fistula. After 6 weeks, magnetic resonance imaging (MRI) was performed in order to confirm fistula formation and measure the fistula diameter. The rabbits were divided into three groups. Group 1 received no plug treatment (control). Autologous dermal graft and acellular dermal matrix were used as a plug in groups 2 and 3, respectively. Five weeks after treatment, fistula tract healing was determined by measuring the largest fistula diameter with MRI. All rabbits were euthanized and the anorectum excised en bloc for histopathological examination.

RESULTS

According to the MRI findings, all groups showed significant healing after the treatment (p < 0.05). The healing rate of fistula diameters after treatment was 40, 66, and 29% in the control, dermal graft, and acellular dermal matrix groups, respectively. In terms of negative healing parameters such as neutrophil, eosinophil, lymphocyte, and plasmocyte accumulation, dermal graft and acellular dermal matrix groups showed significantly lower results than those in the control group (p < 0.05).

CONCLUSION

According to MRI and histopathological results, fistula tract curettage and fistula orifice closure improved transsphincteric anal fistula healing. Additionally, in this study, plug treatment favoring autologous dermal graft resulted in better healing.

Bladder reconstruction using bovine pericardium in a case of enterovesical fistula

The use of graft materials in bladder mucosa has been examined in animal models, but debate exists over which materials are effective. Intestine has been used as a substitute in augmentation cystoplasty for patients with neuropathic bladder, but serious adverse effects of the operation have occurred in some instances. We report a case of a successful repair of an enterovesical fistula by use of bovine pericardium. The patient has remained well for 2.5 years. We suggest that bovine pericardium may be a suitable option as a bladder substitute.

Combined Endorectal Advancement Flap with Alloderm® Graft Repair of Radiation and Cryoablation-Induced Rectourethral Fistula

Rectourethral fistula is a potentially devastating disease for the patient and difficult management problem for the physician. We report a case of radiation and salvage cryoablation-induced rectourethral fistula for treatment of prostate cancer successfully repaired with a combined endorectal advancement flap with Alloderm® graft. The surgical technique is described in detail. The patient is now one year post-repair with no evidence of recurrence.