The rectus myofascial wrap in the management of urethral sphincter incompetence

Pyramidalis muscle formation during human embryonic and early fetal periods

The pyramidalis muscle (PM) is a paired small triangular muscle of the anterior abdominal wall; however, its physiological significance is unclear. Recent studies have failed to detect this muscle during embryonic period. Hence, the present study aimed to determine the time when PM is emerging and reveal its features using high-resolution magnetic resonance imaging. Fourteen embryos between Carnegie stage (CS)18 and CS23 and 59 fetuses (crown-rump length: 39.5-185.0 mm) were selected for this study. The PM was first detected in one of the three samples at CS20. It was detected in five of the seven samples (71.4%) between CS21 and CS23. Forty-eight samples (81.4%) at early fetal period had PMs on both the right and left sides, and 3 (5.1%) had it only on the right side. Eight samples (13.6%) had no PMs. No side-differences or sexual dimorphisms were detected. The PM length was larger than the width in most samples, although the length/width ratio varied among the samples. The PM/rectus abdominis muscle length and PM/umbilicus-pubic symphysis length ratios were almost constant, irrespective of the crown-rump length. The PM was located ventrally inferior to the rectus abdominis and closer to the medial muscle groups of the lower limb than the rectus abdominis. The present study demonstrated that PM formation occurred in the late embryonic period, and that the frequency, side differences, sex dimorphism, and spatial position of the PM in the early fetal period were similar to those in adults.

Prevalence and pubo-umbilical index of pyramidalis muscle in a select Kenyan population

PURPOSE

Pyramidalis is a lower anterior abdominal wall muscle that is considered vestigial and shows variations in prevalence and size. It's been utilized as an anatomical landmark and harvested for use in various surgical procedures. Despite knowledge of its clinical importance, data on the prevalence of pyramidalis remain absent from the Kenyan population with few studies globally reporting on its pubo-umbilical index. We therefore aimed to determine the prevalence and relative lengths (pubo-umbilical index) of pyramidalis muscle in a sample Kenyan population.

MATERIALS AND METHODS

Fifty-two cadavers (41 males, 11 females) from the Department of Human Anatomy, University of Nairobi were used. Prevalence and length of the muscle (l) were established, and the distance between pubic symphysis and umbilicus (L) measured and used to calculate pubo-umbilical index (l/L ×100%). Independent and paired T tests were done, using SPSS® version 22. A p value of ≤ 0.05 was considered statistically significant at a 95% confidence interval.

RESULTS

Pyramidalis was present in 84% (44) of cadavers; 83% (43) bilaterally, 2% (1) unilaterally, and 85.4% (35) in males, 81.8% (9) in females. Mean length in males and females was 71.8 ± 35 mm and 63.5 ± 37.5 mm, respectively. Mean pubo-umbilical index was 38% ± 18 (39 % ± 18 males, 35% ± 19 females). No statistically significant difference was found.

CONCLUSION

Pyramidalis is a highly prevalent muscle in the Kenyan population and, hence, could be exploited for its clinical and surgical utilities. The muscle terminates largely within the 2nd quarter (25-50%) of the infra-umbilical linea alba measured from pubic symphysis. Its pubo-umbilical index would be useful to surgeons making midline infra-umbilical incisions and performing procedures involving the muscle.

Anatomical variations of the pyramidalis muscle: a systematic review and meta-analysis

PURPOSE

To provide a comprehensive evidence-based assessment of the anatomical characteristics of the pyramidalis muscle (PM).

MATERIALS AND METHODS

A thorough systematic search of the literature through August 31st 2020 was conducted on major electronic databases PubMed, Scopus and Web of Science (WOS) to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using MetaFor package in R and MetaXL. A random-effects model was applied. The primary outcome of interest was the prevalence of PM. The secondary outcomes were the dimensions (length and width) of the PM.

RESULTS

A total of 11 studies (n = 787 patients; 1548 sides) were included in the meta-analysis. The multinomial pooled prevalence estimate (PPE) for a bilateral absence of the PM was 11.3% (95% CI [7.2%, 16.2%], 82.3% (95% CI [76.2%, 87.6%]) for a bilateral presence, and 6.3% (95% CI [3.3%, 10.2%]) for a unilateral presence. Of four studies (n = 37 patients) that reported the side of a unilateral presence, the PPE of a unilateral right-side presence was 42.2% (95% CI [23.0%, 62.3%]) compared to 57.8% for a unilateral left-side presence (95% CI [37.7%, 77.0%]). The mean length of the PM displayed high levels of heterogeneity, ranging from 3.12 to 12.50 cm.

CONCLUSION

The pyramidalis muscle is a rather constant anatomical structure being present in approximately 90% of individuals.

Management options for sphincteric deficiency in adults with neurogenic bladder

Neurogenic bladder is a very broad disease definition that encompasses varied disease and injury states affecting the bladder. The majority of patients with neurogenic bladder dysfunction do not have concomitant intrinsic sphincteric deficiency (ISD), but when this occurs the challenges of management of urinary incontinence from neurogenic bladder are compounded. There are no guidelines for surgical correction of ISD in adults and most of the literature on treatment of the problem comes from treatment of children with congenital diseases, such as myelomeningocele. Our goal, in this review, is to present some of the common surgical options for ISD [including artificial urinary sphincters, bladder slings, bladder neck reconstruction (BNR) and urethral bulking agents] and the evidence underlying these treatments in adults with neurogenic bladder.

Neuromodulation of perineally transposed antropylorus with pudendal nerve anastomosis following total anorectal reconstruction in humans

BACKGROUND

We have reported perineal antropyloric segment transposition with its pudendal innervation as a replacement for anal sphincter. Our aim herein was to neuromodulate this segment by electrical stimulation.

METHODS

Eight patients with a permanent colostomy underwent perineal antropyloric segment transposition followed by neural anastomosis of its anterior vagus branch to pudendal nerve branch in the perineum. Perineal antropyloric graft was assessed for its functional integrity and electrophysiological effects. Nerve stimulation was done by surface stimulation technique, using a customized stimulation protocol for smooth muscle. Antral pressures were recorded on voluntary attempts and on nerve stimulation with simultaneous concentric needle electromyography of the perineal antropylorus.

KEY RESULTS

The antral segment showed slow spontaneous contractions (2-3/min) on digital examination, endoscopy, and electrophysiology. Stimulated antropyloric electromyography showed a latency of 2-5 s with a differential rise in amplitude (mean range 58.57-998.75 μV) according to the frequency of stimulation (range 10-150 Hz). An average latency of 10 s in relation to rise in the antral pressure was observed on pudendal nerve stimulation. Triggering of the intrinsic rhythm was observed in patients where it was initially absent. Voluntary attempts at contraction also showed a rise in perineally transposed antral pressure.

CONCLUSIONS & INFERENCES

Spontaneous rhythm, its generation after electrical stimulation, and response to voluntary contraction demonstrates the viability and functional reinnervation of the perineally transposed antropyloric segment. Rise in pressure on electrical stimulation shows evidence for its neuromodulation.

Efficacy of the bulbourethral autologous sling in treating male stress urinary incontinence: a three-year experience from a single center

AIM

To evaluate the efficacy of the bulbourethral rectus autologous sling in treating male stress urinary incontinence.

PATIENTS AND METHODS

We retrospectively reviewed operative logs from a single surgeon of 32 male patients treated over a 3-year period (March 2001 to March 2004) for stress incontinence by implantation of a bulbourethral free rectus sling. The mean age of the patients was 46.4 (range 14-76); mean follow-up time was 29.5 months (range 24-52). Neurogenic dysfunction was the most common cause of incontinence in this group (17/32 cases; 53.1%). Efficacy was evaluated objectively in terms of the number of pads used per day, subjective patient satisfaction, and morbidity. We also investigated a possible correlation between pre-operative parameters and outcome.

RESULTS

Ten patients (31.3%) were cured (totally dry, 15.6%; the remainder one pad per day), while five (15.6%) patients improved but still required two pads per day. Overall, 15 of 32 patients (46.9%) were satisfied with the outcome of the operation. In total, seven patients presented a mild complication (21.9%). De novo urgency was the most common complication presented in four of 32(11.6%). No case of urethral erosion was encountered. Univariate analysis failed to find any correlation between the final outcome and the following parameters: patient age, duration of incontinence, earlier anti-incontinence surgery, severity of pre-operative incontinence, pre-operative Valsalva leak point pressure, decreased compliance, decreased bladder capacity, and pre-operative evidence of detrusor overactivity.

CONCLUSIONS

In conclusion, the free rectus fascia bulbourethral sling is a modestly effective technique for the treatment of male stress incontinence with mild morbidity. The use of this method seems that it is suitable for selected cases.

Spiral Sling Salvage Anti-Incontinence Surgery in Female Patients With a Nonfunctional Urethra: Technique and Initial Results

PURPOSE

Female patients with severe urethral incompetence are a unique surgical challenge. Urethral closure and continent diversion are often the next step in the treatment of these patients. We present a technique that provides circumferential coaptation of the urethra as a salvage procedure in this severe subset of patients.

MATERIALS AND METHODS

We prospectively evaluated 47 patients who had a spiral sling. A 1 x 15 cm piece of soft polypropylene mesh was prepared with a zero polyglactin suture applied at each end. A clamp was used to pass the mesh between the urethra and pubis. The ends of the mesh were crossed at the ventral aspect of the urethra, creating a complete circle around the urethra. The sutures were transferred to the suprapubic area and tied without tension. The surgical outcome was determined by patient self-assessment, including symptom, bother and quality of life questionnaires.

RESULTS

Mean patient age was 59 years. At presentation patients had undergone a mean of 2.6 incontinence procedures and wore a mean of 6 pads daily. Mean daily pad use decreased to 0.9 (p <0.005). Preoperatively mean SUI symptom severity and bother scores were 2.8 and 2.9, respectively, on a scale of 0--none to 3--severe. Postoperatively these values decreased to 0.6 and 0.4, respectively (each p <0.005). There was a mean 87% overall improvement in symptoms.

CONCLUSIONS

The spiral sling is an effective salvage transvaginal procedure that may be considered in a small subset of female patients with a nonfunctional urethra as a last resort before urethral closure procedures.

Bladder Neck Cinch for Pediatric Neurogenic Outlet Deficiency

PURPOSE

The fascial bladder neck sling achieves continence in 50% to 90% of children with neurogenic outlet deficiency. Most slings apply only partial pressure around the bladder neck. We evaluated the effectiveness of a rectus fascia bladder neck cinch which applies circumferential pressure around the bladder neck and elevation as a means of increasing outlet resistance.

MATERIALS AND METHODS

Fifteen children with spina bifida underwent a fascial bladder neck cinch procedure at the time of augmentation cystoplasty. A 1 to 1.5 cm width of variable length rectus fascia was harvested and a vertical slit was made in 1 end. The fascia was "cinched" tightly around the bladder neck and secured to the symphysis or rectus fascia.

RESULTS

The 14 girls and 1 boy ranged in age range from 4 to 17 years. All children had neurogenic intrinsic sphincter deficiency and a poorly compliant and/or small capacity bladder. Followup ranged from 10 to 36 months (followup in 12 greater than 1 year). Postoperatively, all children perform clean intermittent catheterization. At the last followup 8 girls and the boy (60%) were dry (no leak and no pads at 4 hours from the last catheterization and dry throughout the night).

CONCLUSIONS

Rectus fascia used as a bladder neck cinch is effective but no better than other bladder neck slings for decreasing urinary incontinence. The bladder neck cinch appears to be an acceptable addition to the technique of fascial slings. However, we have subsequently changed our technique because these results did not meet our expectations.