Long-term cryopreservation of pyramidalis muscle specimens as a source of striated muscle stem cells for treatment of post-prostatectomy stress urinary incontinence

Reappraisal of the anatomical diversities of the pyramidalis muscle with their potential clinical applicability: cadaveric analysis

INTRODUCTION

The present study examined the morphology and morphometric parameters of the pyramidalis muscle (PM) in detail with their potential applicability in making midline infra-umbilical incisions and biomechanics of the linea alba.

METHODS

PM was examined in 51 formalin-fixed cadavers (36 males and 15 females), and based on the mode of insertion or the level of apex, the formation or shape of the muscle was classified into nine types (Mori's classification).

RESULTS

Bilateral PM was more prevalent (39.21%) than unilateral (1.96%) (p = 0.001). All the cases showed side symmetry except one. Mori's type 7 (right PM is higher apex and the left PM with elongated origin) was the most common form. The mean length of PM in males and females was 4.51 ± 0.14 and 3.33 ± 0.12 cm on the right and 4.51 ± 0.11 and 3.26 ± 0.16 cm on the left side. The mean width of right-sided PMs in males and females was 1.90 ± 0.17 and 1.58 ± 0.13 cm and left-sided 1.88 ± 0.14 and 1.55 ± 0.38 cm. The mean of pyramidalis-pubo-umbilical index (PPI) in males and females was 32.82 ± 1.65 and 27.50 ± 1.08, respectively. The mean insertion angle was 24.56 ± 3.07 on right side and 23 ± 2.03 on the left side (p = 0.03). Male predominance existed on right- and left-sided PM length (p < 0.001 and p < 0.001), width (p = 0.001) and PPI (p = 0.001). The strong positive correlation (r = 0.83) between length and width indicates a symmetrical muscle augmentation in the two dimensions.

CONCLUSION

PM is an inconsistent anatomical structure with persistent morphology. The level and angle of insertion into the linea are crucial in the biomechanics of linea alba. PPI, determining the termination level would be useful to surgeons making midline infra-umbilical incisions.

Morphometry of pyramidalis muscle and its role in reconstructive surgeries: A cadaveric study in South Indian population

Background

The pyramidalis muscle is a tiny triangular-shaped muscle that is located in the anterior abdominal wall, which originates from the body of the pubis and pubic symphysis and is inserted into linea alba. This study aimed to measure the different parameters of the pyramidalis muscle in adult cadavers.

Methods

This study was carried out on 31 adults (26 males and five females) 10% formalin embalmed cadavers of both sexes from the Department of Anatomy at Kasturba Medical College, Manipal.

Results

The mean length of the right pyramidalis muscle was 64.44 ± 12.52 mm and the left pyramidalis muscle was 64.73 ± 12.81 mm. The mean width of the muscle was 15 ± 4.18 mm and 15.03 ± 3.52 mm on the right and left sides, respectively. The mean thickness of the muscle was 1.32 ± 0.55 mm and 1.4 ± 0.80 mm on the right and left sides, respectively. The distance between the umbilicus to pubic symphysis ranged from 130-192 mm and their mean was calculated to be 159.77 ± 15.36. The distance between the umbilicus and the apex of the muscle ranged from 72-123 mm.

Conclusions

The measured parameters like length, width and thickness may help the surgeons to locate the muscle during infra umbilical surgeries.

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.

Morphometry and Frequency of the Pyramidalis Muscle in Adult Humans: A Pyramidalis Muscle's Anatomical Analysis

OBJECTIVES

To verify the pyramidalis muscle's frequency (bilaterality, unilaterality, or absence) and morphometry (length of the medial border and width of its origin/base) in a sample of the Brazilian population and the anthropometric influence.

METHODS

Dissection of 30 cadavers, up to 24h post-mortem.

RESULTS

The pyramidalis muscle was present bilaterally and unilaterally in 83.33% and 3.33% of the cadavers, respectively, and absent in 13.33%. The muscles on the right and left sides were symmetrical in length but not in width; the pyramidalis muscles of men were longer, while those of the women were wider. We also found that there was greater variation in the dimensions (length and width) of the men's muscles. Finally, in this sample of the Brazilian population, the pyramidalis muscle's unilaterality was more prevalent than in other populations, and its complete absence was less prevalent.

CONCLUSIONS

There were no cases of muscle duplication in one or both sides, as described in some studies. Despite all of its morphometric variation, the pyramidalis muscle maintained its triangular shape with longitudinal fibers in every case. Furthermore, no statistically significant correlation was noted between the muscles' dimensions and person's age, height, weight, or gender.

Isolation and characterization of myogenic precursor cells from human cremaster muscle

Human myogenic precursor cells have been isolated and expanded from a number of skeletal muscles, but alternative donor biopsy sites must be sought after in diseases where muscle damage is widespread. Biopsy sites must be relatively accessible, and the biopsied muscle dispensable. Here, we aimed to histologically characterize the cremaster muscle with regard number of satellite cells and regenerative fibres, and to isolate and characterize human cremaster muscle-derived stem/precursor cells in adult male donors with the objective of characterizing this muscle as a novel source of myogenic precursor cells. Cremaster muscle biopsies (or adjacent non-muscle tissue for negative controls; N = 19) were taken from male patients undergoing routine surgery for urogenital pathology. Myosphere cultures were derived and tested for their in vitro and in vivo myogenic differentiation and muscle regeneration capacities. Cremaster-derived myogenic precursor cells were maintained by myosphere culture and efficiently differentiated to myotubes in adhesion culture. Upon transplantation to an immunocompromised mouse model of cardiotoxin-induced acute muscle damage, human cremaster-derived myogenic precursor cells survived to the transplants and contributed to muscle regeneration. These precursors are a good candidate for cell therapy approaches of skeletal muscle. Due to their location and developmental origin, we propose that they might be best suited for regeneration of the rhabdosphincter in patients undergoing stress urinary incontinence after radical prostatectomy.

Sonic hedgehog regulation of human rhabdosphincter muscle:Potential implications for treatment of stress urinary incontinence

AIMS

Rhabdosphincter (RS) muscle injury occurs during prostatectomy, and is a leading cause of stress urinary incontinence (SUI). Current SUI treatments engender significant side effects, which negatively impact patient quality of life. Thus an unmet need exists to develop novel RS regeneration methods. We have shown that Sonic hedgehog (SHH) is a critical regulator of penile smooth muscle, and we have developed novel peptide amphiphile nanofiber hydrogel delivery of SHH protein to the penis to regenerate smooth muscle after prostatectomy induced injury. If similar SHH signaling mechanisms regulate RS muscle homeostasis, this innovative technology may be adapted for RS regeneration post-prostatectomy. We examine the SHH pathway in human RS muscle.

METHODS

Human RS obtained during radical cystoprostatectomy (n = 13), underwent SHH pathway analysis. Primary cultures were established (n = 5), and RS cells were treated with SHH protein, SHH inhibitor, or PBS (control). Immunohistochemical analysis for SHH pathway, skeletal muscle actin, and trichrome stain were performed. RS growth was quantified at 3 and 6 days.

RESULTS

SHH, it is receptors patched and smoothened, and transcriptional activators, GLI proteins, were identified in human RS muscle. At 3 and 6 days, RS cells increased 62% and 78% (P = 0.0001) with SHH treatment and decreased 40% (P = 0.0001) and 18% (P = 0.039) with SHH inhibition.

CONCLUSIONS

The SHH pathway was identified in human RS. RS growth increased with SHH treatment, indicating intervention may be possible to enhance RS regeneration, and impact SUI. Peptide amphiphile delivery of SHH may be applicable for RS regeneration and SUI prevention.

Biometrics of Pyramidalis Muscle and its Clinical Importance

INTRODUCTION

Pyramidalis is classified as a vestigial muscle which is frequently present. It is muscle of the anterior abdominal wall. It is thought to tense the linea alba. It has been used as a surgical landmark, source of muscle stem cells and in various surgical procedures.

AIM

The aim of this study was to describe the morphometry and morphology of pyramidalis muscle in an adult Indian population and its correlation with the clinical significance.

MATERIALS AND METHODS

A cadaveric study on 25 formalin fixed cadavers (males-17, females-8) was conducted in context with prevalence, morphology and morphometry of pyramidalis muscle. Statistical analysis was done using the Chi-Square test and student's t-test using SPSS version 23.

RESULTS

The pyramidalis muscle was present in 92% cases, usually bilaterally (72%) than unilaterally (20%) and more frequently in males (94.11%) than in females (87.5%). This study was conducted in Department of Anatomy, Maulana Azad Medical College, New Delhi, India from August 2014 to August 2016. Bilateral asymmetry was reported. The mean length of the muscle in males and females was 52.21±14.32 and 50.13±13.62mm on the right and 53.97±15.11 and 51.22±13.78mm on the left side. No significant gender predominance existed on the right and left-sided pyramidalis lengths. The mean width of the right-sided pyramidalis in males and females was 18.35±5.15 and 17.05±4.99mm and the left-sided was 17.8±4.80 and 16.21±4.23mm without gender dimorphism. The mean thickness of the right-sided pyramidalis in males and females was 4.91±1.33 and 4.53±1.29mm and the left-sided 4.33±1.28 and 4.38±1.27mm without gender differences. The mean pyramidalis-puboumbilical index was 35.15±4.38%, 36.01±4.97% in males and females respectively. No anatomical variations with regard to origin and insertion were seen.

CONCLUSION

This study provides valuable information on pyramidalis muscle which may help in appropriate understanding of anatomy, functions and clinical significance of the muscle.

The proliferative potential of human cardiac stem cells was unaffected after a long-term cryopreservation of tissue blocks

BACKGROUND

Human c-kit-positive cardiac stem cells (CSCs) have been used to treat patients suffering from ischemic cardiomyopathy. This study aimed to investigate whether a long-term storage of cardiac tissues would influence the growth potential of the subsequently isolated CSCs.

METHODS

A total of 34 fresh samples were obtained from various cardiac regions [right atrium (RA), left atrium (LA), and/or left ventricle (LV)] of 21 patients. From 12 of these patients, 18 samples kept frozen for ~2 years were employed to prepare and characterize the CSCs. After confirming the specificity of the cell sorting by c-kit immunolabeling, the growth rate (number of doublings per day), BrdU positivity, and colony forming unit (CFU) were measured in each CSC population; the values were compared among distinct cardiac regions as well as between fresh and frozen tissues from which CSCs were derived.

RESULTS

Among independent measurements indicating growth potential, the growth rate and BrdU positivity remarkably correlated in freshly prepared CSCs. The cells obtained from every examined region displayed a high proliferative capacity with the growth rate of 0.48±0.19 and the BrdU positivity of 15.0%±7.6%. The right atrial CSCs tended to show a greater growth than those in the other two areas. Similarly, the CSCs were isolated from tissue blocks, cryopreserved for ~2 years, and compared with CSCs derived from the fresh specimens of the same patients. Importantly, we were able to obtain and culture CSCs from every frozen material, and their proliferative potential, represented by the growth rate of 0.47±0.22 and the BrdU positivity of 13.7%±7.9%, was not inferior to that of the freshly prepared cells.

CONCLUSIONS

The long-term cryopreservation of cardiac tissues did not affect the growth potential of the derivative CSCs. Our findings should expand the therapeutic applications of these cells over a longer time span.

Morphometric variability of pyramidalis muscle and its clinical significance

PURPOSE

The goal of the study is to analyze the morphometric diversity of the pyramidalis muscle (PM) and to evaluate how it is affected by gender and side of occurrence.

MATERIALS AND METHODS

Ninety-six (50 male and 46 female) formalin-embalmed Greek cadavers were dissected.

RESULTS

The PM was present in 93.8 %, usually bilaterally (79.2 %) than unilaterally (14.6 %) (p = 0.003) and more frequently in females (91.3 %) than in males (68 %) (p = 0.0001). Side symmetry was detected. The mean length of PM in males and females was 8.37 ± 2.80 and 6.18 ± 1.64 cm on the right and 7.50 ± 2.66 and 6.56 ± 1.68 cm on the left side. Male predominance existed on the right and left-sided PM lengths (p = 0.0001 and p = 0.054). The mean width of the right-sided PMs in males and females was 1.61 ± 0.55 and 1.50 ± 0.44 cm and the left-sided 1.56 ± 0.53 and 1.55 ± 0.38 cm without gender dimorphism. The positive correlation between the PM length and width indicates a symmetrical muscle augmentation on the two dimensions.

CONCLUSIONS

The study demonstrates that the PM is almost constant in Greeks. Among populations the muscle morphometric variability, its clinical significance and its variable uses will help surgeons when intervening in the lower abdominal wall.

Development of stem cell therapy for stress urinary incontinence

PURPOSE OF REVIEW

In recent years, stem cell therapy has been investigated as a promising approach for the treatment of stress urinary incontinence (SUI). This article reviews the biology of stem cells and their applications as a cell-based treatment for SUI. The current status and future direction of this forefront research in urinary incontinence are also examined.

RECENT FINDINGS

During the past decade, adult stem cells have been studied as a potential cell-based approach for the treatment of SUI. The results of current preclinical and clinical studies are presented. These studies demonstrated the improvement in histologic and functional outcomes with stem cell therapies for SUI. Adult stem cells may augment sphincter regeneration and also release trophic factors, promoting vessel and nerve integration into the generated tissues. So far, the findings of the clinical trials are less impressive than the results obtained with animal studies.

SUMMARY

Although stem cell therapy holds much promise for SUI, the clinical applications in patients have been slow to materialize. This challenge, together with the currently limited data on basic science studies and clinical trials, will undoubtedly stimulate new investigations in the near future.

Promotion of bone repair by implantation of cryopreserved bone marrow-derived mononuclear cells in a rabbit model of steroid-associated osteonecrosis

OBJECTIVE

Cytotherapy is an insufficient method for promoting bone repair in steroid-associated osteonecrosis (SAON), and this has been attributed to impairment of the bioactivity of bone marrow-derived stem cells (BMSCs) after pulsed administration of steroids. Cryopreserved autologous bone marrow-derived mononuclear cells (BMMNCs), which contain BMSCs, might maintain their bioactivity in vitro. This study sought to investigate the effects of cryopreserved BMMNCs, before steroid administration, on the enhancement of bone repair in an established rabbit model of SAON.

METHODS

For in vitro study, bone marrow was harvested 4 weeks before SAON induction from the iliac crests of rabbits (n = 10) to isolate fresh BMMNCs, and the BMMNCs were then cryopreserved for 8 weeks. Both the fresh and the cryopreserved BMMNCs were evaluated for their bioactivity and osteogenic differentiation capacity. In addition, BMMNCs were isolated 2 weeks after SAON induction and subjected to the same evaluations. For in vivo study, cryopreserved BMMNCs were implanted into the bone tunnel during core decompression of the femur (n = 12 rabbits) after the induction of SAON, and tissue regeneration was evaluated by micro-computed tomography and histologic analyses at 12 weeks postoperation.

RESULTS

In vitro, there were no significant differences in the bioactivity or ability to undergo osteogenic differentiation between fresh BMMNCs and cryopreserved BMMNCs, but after SAON induction, both features were decreased significantly. In vivo, the bone mineral density, ratio of bone volume to total volume of bone, and volume and diameter of neovascularization within the bone tunnel were significantly higher in the BMMNC-treated group compared to the nontreated control group at 12 weeks postoperation.

CONCLUSION

Cryopreserved BMMNCs maintained their bioactivity and promoted bone regeneration and neovascularization within the bone tunnel after core decompression in this rabbit model of SAON.

Male stress urinary incontinence: a review of surgical treatment options and outcomes

Introduction and Objective. Iatrogenic male stress urinary incontinence (SUI) affects a percentage of men undergoing urologic procedures with a significant impact on quality of life. The treatment of male SUI has evolved significantly with multiple current options for treatment available. The current paper discusses preoperative evaluation of male SUI, available surgical options with reported outcomes, and postoperative complication management. Methods. A pubMed review of available literature was performed and summarized on articles reporting outcomes of placement of the artificial urinary sphincter (AUS) or male slings including the bone anchored sling (BAS), retrourethral transobturator sling (RTS), adjustable retropubic sling (ARS), and quadratic sling. Results. Reported rates of success (variably defined) for BAS, RTS, ARS, and AUS are 36-67%, 9-79%, 13-100%, and 59-91% respectively. Complications reported include infection, erosion, retention, explantation, and transient pain. Male slings are more commonly performed in cases of low-to-moderate SUI with decreasing success with higher degrees of preoperative incontinence. Conclusions. An increasing number of options continue to be developed for the management of male SUI. While the AUS remains the gold-standard therapy for SUI, male sling placement is a proven viable alternative therapy for low-to-moderate SUI.