Stress Urinary Incontinence and Pelvic Organ Prolapse: Biologic Graft Materials Revisited

Application and research progress in composite stem cell materials of pelvic floor reconstruction

As an important tool for the surgical treatment of pelvic floor dysfunction, the safety of mesh must be guaranteed. Although the short-term curative effect of most synthetic mesh is satisfactory, complications often occur due to its material. Planting stem cells on mesh through specific methods may resolve the problems of mesh with poor biocompatibility or an uncontrollable rate o degradation. Based on recent research, this paper summarizes the research progress of stem cells composited with common mesh materials, such as polypropylene, polylactic acid and acellular matrix.

Mid-term outcomes of moderate-severe cystocele repairing with autologous fascia lata harvested through a small incision

INTRODUCTION AND HYPOTHESIS

To investigate the mid-term outcomes of transvaginal repair for moderate-severe cystocele using autologous fascia lata harvested through a single small incision.

METHODS

Between February and October 2022, 35 patients with moderate to severe cystocele undergoing transvaginal repair with autologous fascia lata were included. Patient demographics and perioperative data were collected, with follow-ups through outpatient visits or phone calls. Patients were evaluated by subjective perception of vaginal bulging, physical examination, Pelvic Floor Distress Inventory (PFDI-20) Questionnaire, patient satisfaction, Patient Global Impression of Improvement (PGI-I) scores, regret rate, willingness to recommend, complications, and harvesting site issue.

RESULTS

The patient's mean age was 60.44 ± 6.01 years. Fascia lata harvesting took 32.92 ± 19.72 min, reconstruction surgery lasted 141.21 ± 37.89 min. Follow-up duration was 15.94 ± 2.46 months. 5.7% (2/35) of the patients reported a non-interfering vaginal bulge not requiring treatment. Objective recurrence rate was 4.26% (1/24, Aa or Ba>0) PFDI-20 was significantly improved (P < 0.0001). All 35 patients (100%) were highly satisfied, with PGI-I score very much improved or improved. No patient regretted. 97.14% (34/35) would recommend the procedure. One patient developed poor wound healing at the vaginal apex. One patient developed thromboembolic event. Harvest site: 2.86% (1/35) developed a non-bothersome thigh bulge, 17.14% (6/35) noted an impact on wound appearance, and 8.57% (3/35) reported mild paresthesia.

CONCLUSION

Autologous fascia lata for cystocele treatment shows promising mid-term outcomes, safely and effectively enhancing QoL with high satisfaction. Despite concerns about leg scarring, no patient regretted and would recommend the procedure. Long-term outcomes require larger follow-up studies.

Supramolecular Fibrous Hydrogel Augmentation of Uterosacral Ligament Suspension for Treatment of Pelvic Organ Prolapse

Uterosacral ligament suspension (USLS) is a common surgical treatment for pelvic organ prolapse (POP). However, the relatively high failure rate of up to 40% underscores a strong clinical need for complementary treatment strategies, such as biomaterial augmentation. Herein, the first hydrogel biomaterial augmentation of USLS in a recently established rat model is described using an injectable fibrous hydrogel composite. Supramolecularly-assembled hyaluronic acid (HA) hydrogel nanofibers encapsulated in a matrix metalloproteinase (MMP)-degradable HA hydrogel create an injectable scaffold showing excellent biocompatibility and hemocompatibility. The hydrogel can be successfully delivered and localized to the suture sites of the USLS procedure, where it gradually degrades over six weeks. In situ mechanical testing 24 weeks post-operative in the multiparous USLS rat model shows the ultimate load (load at failure) to be 1.70 ± 0.36 N for the intact uterosacral ligament (USL), 0.89 ± 0.28 N for the USLS repair, and 1.37 ± 0.31 N for the USLS + hydrogel (USLS+H) repair (n = 8). These results indicate that the hydrogel composite significantly improves load required for tissue failure compared to the standard USLS, even after the hydrogel degrades, and that this hydrogel-based approach can potentially reduce the high failure rate associated with USLS procedures.

Exploratory safety study of an umbilical cord derived urethral sling in bilateral pudendal nerves injury-induced urinary incontinence in female rats

PURPOSE

Mid-urethral slings are the standard treatment for women with refractory stress urinary incontinence (SUI) but are at risk of infection or erosion due to host-prothesis interaction. In this proof-of-concept study, we aimed at evaluating umbilical vessel sling (UVS) in incontinent female rats.

MATERIAL AND METHODS

UVS was extracted from human umbilical cord lining and was placed on female rats who underwent bilateral pelvic nerve injury (PNI) to reproduce SUI (Group 3, N = 10). Two control groups were also studied: rats with no PNI (Group 1, N = 4) and rats with PNI but no UVS (Group 2, N = 10). Micturition calendar was frequently recorded using a metabolic cage, and leak point pressure (LPP) test was performed on Day 28. After the LPP test, rats were euthanized, and bladder/urethra were collected for histopathological analysis.

RESULTS

Overall, 24 rats were included, of whom 10 had both PNI and UVS placement. Compared with Group 2, Group 3 had increased maximal LPP but the difference did not reach significance (respectively 21.8 ± 2.1 mmHg vs. 28.4 ± 4.1 mmHg, p = 0.2). Micturition frequencies were similar between the groups. Total voided volume was higher in Group 3 at the end of the study compared with Group 2 (12.5 ± 1.1 ml vs. 9.4 ± 0.6 ml, respectively, p < 0.05). Histopathological findings evidenced a good local tolerance and a moderate to high tissue integration of the UVS.

CONCLUSIONS

Biological sling derived from human umbilical vessel could be safely placed with a slight improvement of LPP in a population of rats who had bilateral PNI without major modification of micturition calendar. UVS could be a promising biomaterial in the management of SUI in women. Clinical studies are needed.

Effect of Mammalian Tissue Source on the Molecular and Macroscopic Characteristics of UV-Cured Type I Collagen Hydrogel Networks

The tissue source of type I collagen is critical to ensure scalability and regulation-friendly clinical translation of new medical device prototypes. However, the selection of a commercial source of collagen that fulfils both aforementioned requirements and is compliant with new manufacturing routes is challenging. This study investigates the effect that type I collagen extracted from three different mammalian tissues has on the molecular and macroscopic characteristics of a new UV-cured collagen hydrogel. Pepsin-solubilised bovine atelocollagen (BA) and pepsin-solubilised porcine atelocollagen (PA) were selected as commercially available raw materials associated with varying safety risks and compared with in-house acid-extracted type I collagen from rat tails (CRT). All raw materials displayed the typical dichroic and electrophoretic characteristics of type I collagen, while significantly decreased lysine content was measured on samples of PA. Following covalent functionalisation with 4-vinylbenzyl chloride (4VBC), BA and CRT products generated comparable UV-cured hydrogels with significantly increased averaged gel content (G ≥ 97 wt.%), while the porcine variants revealed the highest swelling ratio (SR = 2224 ± 242 wt.%) and an order of magnitude reduction in compression modulus (Ec = 6 ± 2 kPa). Collectively, these results support the use of bovine tissues as a chemically viable source of type I collagen for the realisation of UV-cured hydrogels with competitive mechanical properties and covalent network architectures.