In vivo recovery of the injured anal sphincter after repair and injection of myogenic stem cells: an experimental model.

OBJECTIVE: This study aims to evaluate in vivo function of the external anal sphincter after transection and repair augmented with myogenic stem cells, and to establish normative electromyography parameters of the rodent external anal sphincter. DESIGN AND SETTING: Thirty-three Sprague-Dawley rodents underwent baseline needle electromyography of the external anal sphincter. Motor unit action potentials were obtained and normative parameters established. Animals were randomly assigned to a myogenic stem cell group (n = 24) or control group (n = 9). All underwent proctoepisiotomy. The control group underwent layered repair with phosphate-buffered saline injection to the external anal sphincter. The treatment group underwent identical repair with injection of myogenic stem cells 5.0 × 10. Baseline anal pressure recordings were collected and repeated 2 weeks postintervention, and electromyography was repeated at 2 and 4 weeks. Groups were compared across 3 time points with the use of repeated measures ANOVA. MAIN OUTCOME MEASURES: The primary outcomes measured were the functional recovery of rat anal sphincters after stem cell transplantation as assessed by objective electromyography and anal pressure measures. RESULTS: A mean of 17 motor unit action potentials were sampled per animal. At 2 weeks postrepair, there was a significant difference between control and transplant groups with respect to amplitude, duration, turns, and phases (p < 0.01 for each). No significant electromyography differences were seen at 4 weeks. Resting and peak anal pressures declined significantly at 2 weeks postinjury in the control but not in the stem cell group. LIMITATIONS: Use of a murine animal population limited the subjective feedback and wider applicability. CONCLUSIONS: In vivo functional studies show recovery of anal sphincter pressures and electromyography to preinjury levels by day 14 in the myogenic stem cell group but not controls. At 4 weeks, all electromyography parameters returned to baseline irrespective of group. Restoration of function may be accelerated by the transplantation of myogenic stem cells and associated trophic factors.

Reconstructive pelvic surgery and plastic surgery: safety and efficacy of combined surgery.

OBJECTIVE: The purpose of this study was to address the safety of combining aesthetic and pelvic floor reconstructive procedures. STUDY DESIGN: Fifty-four subjects were included in a case-control study; 18 patients undergoing combined pelvic and plastic reconstructive surgery, age and procedure matched to 18 pelvic surgery and 18 plastic surgery only controls. Chi-square, t test, and Kruskal-Wallis analysis were used to compare the estimated blood loss (EBL), body mass index (BMI), hospital days, operative times, and complications between the groups. RESULTS: No differences were seen with regards to age, BMI, or EBL. There was, however, a significant increase in minor complications and hospital stay after combined procedures relative to the pelvic surgery control group but not the aesthetic control group. Operative times were only greater during combined procedures relative to isolated pelvic floor procedures. CONCLUSION: Combining pelvic and aesthetic procedures may increase complications, operative times, and length of hospital stay when compared to pelvic reconstructive surgery alone.

The effect of age and medical comorbidities on in vitro myoblast expansion in women with and without pelvic organ prolapse.

INTRODUCTION: This is an observational study is designed to assess the influence of age, prolapse and medical co-morbidities on myogenic stem cells growth in-vitro. METHODS: A biopsy of the rectus abdominus muscle was obtained during surgery in patients with and without pelvic organ prolapse (POP). Nuclei number and fiber count were correlated with patient's age, presence of POP, and medical comorbidities. Efficiency of expansion of myogenic stem cells in vitro was calculated. The percentage of Pax7-, MyoD-, and desmin-positive cells was correlated with age, POP status, and medical comorbidities. RESULTS: A total of 17 specimens were obtained; 13 specimens were available for histologic analysis. There was no correlation between patient's age, POP status or medical comorbidities and nuclei or fiber count, growth rate, or the percentage of Pax7- and MyoD-positive cells. Patients with 2 to 4 medical comorbidities were noted to have a significantly lower percentage of desmin-positive cells. Specimens with a higher nuclear count had significantly better cellular expansion. Data were analyzed using Kruskal-Wallis or Wilcoxon rank sum statistics. CONCLUSIONS: Multiple medical comorbidities but not patient's age or POP status influenced in vitro myogenic stem cell growth. These data suggest that patients with advancing age or POP may be acceptable autologous donors if treatment of urinary or anal incontinence requires myoblast transplantation.

Allogenic myoblast transplantation in the rat anal sphincter.

OBJECTIVES: : To determine the feasibility of injecting rat myoblasts into the intact anal sphincter as a potential treatment for anal incontinence, and to detect transferred myoblast survival and integration. STUDY DESIGN: : A pilot study using nonpregnant female Sprague Dawley rodents of 8 to 10 weeks of age. A biopsy of skeletal muscle was harvested from a study animal and recovered myoblasts were expanded in vitro over 10 days. Myoblasts were then tagged with a cytomegalovirus promoter to transduce green fluorescent protein (GFP) into the myoblasts. The cell aspirate was injected directly into the intact external anal sphincter using an electromyographic guidance. The animals received 1.5 or 4.5 × 10 cells of GFP-labeled myoblasts, dividing the dose between three injection sites. The remaining in vitro myoblasts were still viable 28 days post-harvest. Ten days after transplantation the anal sphincter complex was surgically extracted. RESULTS: : The presence of GFP-labeled myoblasts was confirmed within the external anal sphincter. CONCLUSIONS: : This demonstrates that myoblasts can be successfully extracted, cultivated in vitro, transplanted and will integrate into the host tissue.