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.

Core Synergies Measured with Ultrasound in Subjects with Chronic Non-Specific Low Back Pain and Healthy Subjects: A Systematic Review.

Low back pain represents the leading cause of disability since 1990. In 90% of cases, it is classified as non-specific low back pain, being chronic in 10% of subjects. Ultrasound has proven to be an effective measurement tool to observe changes in the activity and morphology of the abdominal muscles. This article reviews which core synergies are studied with ultrasound in healthy subjects and with chronic non-specific low back pain. A systematic review was conducted on studies analyzing synergies between two or more core muscles. Publications from 2005 until July 2021 were identified by performing structured searched in Pubmed/MEDLINE, PEDro and WOS. Fifteen studies were eligible for the final systematic review. A total of 56% of the studies established synergies between the core muscles and 44% between the homo and contralateral sides of the core muscles. The most studied core synergies were transversus abdominis, internal oblique and external oblique followed by the rectus abdominis and the lumbar multifidus. No studies establishing synergies with diaphragm and pelvic floor were found. Eight studies were conducted in healthy subjects, five studies in subjects with chronic non-specific low back pain compared to healthy subjects and two studies in subjects with chronic non-specific low back pain.

Enhancing the Appearance of the "Six-Pack" Muscles Using Cryolipolysis: A Safe and Effective Method.

SUMMARY: Many individuals desire a defined and athletic body with "six-pack" abdominal muscles, but even with a strict regimen of diet and exercise, this result is unattainable for many. Cryolipolysis is a noninvasive method of reducing the subcutaneous adipose tissues lying above the rectus abdominis muscles, enhancing the six-pack appearance. Eleven nonobese adults with an average body mass index of 22.5 kg/m2 were enrolled in this study. All subjects were treated with the CoolSculpting cryolipolysis system, with most of them undergoing two rounds of treatment. Improvement in appearance of the abdominal muscles was rated using the Global Aesthetic Improvement Scale, and adverse events and subjects' satisfaction scores were recorded. Treatments were well tolerated, with no reported instances of blanching, bruising, or blistering, and with only mild cases of edema, erythema, and numbness reported by some. Mean Global Aesthetic Improvement Scale rating was 1.7, corresponding to a rating of improved to much improved. Subjects were comfortable with the procedure and satisfied with the results. In conclusion, cryolipolysis is an effective and well-tolerated method for noninvasive enhancement of abdominal muscle definition.

Topografia dos órgãos abdominais em Didelphis albiventris / Topography of abdominal organs in Didelphis albiventris

O conhecimento da localização dos órgãos nas diferentes regiões do corpo do animal é essencial para a prática clínica, cirúrgica e para o diagnóstico por imagem. O objetivo do estudo foi descrever a anatomia topográfica abdominal do Didelphisalbiventris. Foram utilizados quatro cadáveres (animais jovens), dois destes destinados para o estudo macroscópico em peças a fresco e os outros fixados em solução aquosa de formaldeído a 10%. Os cadáveres foram dissecados e as estruturas anatômicas identificadas, analisadas e fotografadas. A maioria dos órgãos localizados na região abdominal dos cadáveres da espécie D. albiventris apresentou posição similar aos dos caninos, porém, alguns órgãos e a localização de determinadas estruturas apresentaram particularidades importantes, como a presença dos ossos epipúbicos, a ausência do lobo hepático quadrado, a presença de um ceco desenvolvido e o cólon dividido em três segmentos.

The knowledge about localization of organs in different regions of the animal's body is essential for clinical, surgical and diagnostic imaging practice. The purpose of this study was to describe the abdominal topographic anatomy of Didelphis albiventris. Was used four dead bodys (young animals), two of these was intended for the macroscopic study of fresh pieces and the others fixed in 10% aqueous formaldehyde solution. The corpses was dissected and the anatomic structures was identified, analyzed and photographed. Most of the organs located in the abdominal region of cadavers from species D. albiventris presented structure and position similar to canines, however some of these organs and localization of structures presented important particularities, like the presence of epipubic bones, absence of square hepatic lobe, presence of an developed cecum and colon divided into three segments.

Topografia dos órgãos abdominais em Didelphis albiventris / Topography of abdominal organs in Didelphis albiventris

O conhecimento da localização dos órgãos nas diferentes regiões do corpo do animal é essencial para a prática clínica, cirúrgica e para o diagnóstico por imagem. O objetivo do estudo foi descrever a anatomia topográfica abdominal do Didelphisalbiventris. Foram utilizados quatro cadáveres (animais jovens), dois destes destinados para o estudo macroscópico em peças a fresco e os outros fixados em solução aquosa de formaldeído a 10%. Os cadáveres foram dissecados e as estruturas anatômicas identificadas, analisadas e fotografadas. A maioria dos órgãos localizados na região abdominal dos cadáveres da espécie D. albiventris apresentou posição similar aos dos caninos, porém, alguns órgãos e a localização de determinadas estruturas apresentaram particularidades importantes, como a presença dos ossos epipúbicos, a ausência do lobo hepático quadrado, a presença de um ceco desenvolvido e o cólon dividido em três segmentos.

The knowledge about localization of organs in different regions of the animal’s body is essential for clinical, surgical and diagnostic imaging practice. The purpose of this study was to describe the abdominal topographic anatomy of Didelphis albiventris. Was used four dead bodys (young animals), two of these was intended for the macroscopic study of fresh pieces and the others fixed in 10% aqueous formaldehyde solution. The corpses was dissected and the anatomic structures was identified, analyzed and photographed. Most of the organs located in the abdominal region of cadavers from species D. albiventris presented structure and position similar to canines, however some of these organs and localization of structures presented important particularities, like the presence of epipubic bones, absence of square hepatic lobe, presence of an developed cecum and colon divided into three segments.

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.

Changes in Respiratory Muscle Thickness during Mechanical Ventilation: Focus on Expiratory Muscles.

BACKGROUND: The lateral abdominal wall muscles are recruited with active expiration, as may occur with high breathing effort, inspiratory muscle weakness, or pulmonary hyperinflation. The effects of critical illness and mechanical ventilation on these muscles are unknown. This study aimed to assess the reproducibility of expiratory muscle (i.e., lateral abdominal wall muscles and rectus abdominis muscle) ultrasound and the impact of tidal volume on expiratory muscle thickness, to evaluate changes in expiratory muscle thickness during mechanical ventilation, and to compare this to changes in diaphragm thickness. METHODS: Two raters assessed the interrater and intrarater reproducibility of expiratory muscle ultrasound (n = 30) and the effect of delivered tidal volume on expiratory muscle thickness (n = 10). Changes in the thickness of the expiratory muscles and the diaphragm were assessed in 77 patients with at least two serial ultrasound measurements in the first week of mechanical ventilation. RESULTS: The reproducibility of the measurements was excellent (interrater intraclass correlation coefficient: 0.994 [95% CI, 0.987 to 0.997]; intrarater intraclass correlation coefficient: 0.992 [95% CI, 0.957 to 0.998]). Expiratory muscle thickness decreased by 3.0 ± 1.7% (mean ± SD) with tidal volumes of 481 ± 64 ml (P < 0.001). The thickness of the expiratory muscles remained stable in 51 of 77 (66%), decreased in 17 of 77 (22%), and increased in 9 of 77 (12%) patients. Reduced thickness resulted from loss of muscular tissue, whereas increased thickness mainly resulted from increased interparietal fasciae thickness. Changes in thickness of the expiratory muscles were not associated with changes in the thickness of the diaphragm (R2 = 0.013; P = 0.332). CONCLUSIONS: Thickness measurement of the expiratory muscles by ultrasound has excellent reproducibility. Changes in the thickness of the expiratory muscles occurred in 34% of patients and were unrelated to changes in diaphragm thickness. Increased expiratory muscle thickness resulted from increased thickness of the fasciae.

The fibers of the circular junction of the linea alba in normal adult anatomy.

The linea alba (LA) is known to be useful to surgeons for making surgical incisions. Laparoscopic entry into the peritoneal cavity using the open technique may involve identification of a point just above or below the umbilicus where the peritoneum is fused to the LA. This anatomical site is found through superficial dissection to expose the junction between the umbilical stalk (US) and the LA, where distinct fibers seem to form a unique ligament-like structure in normal adult anatomy. This point, in fact, is part of a circular fibrous structure that exists almost like a ring around the remnant US. It is formed by the fusion of oblique and transverse fibers of the LA with circular fibers from proliferation of an encircling band of compact mesoderm to close a patent umbilical ring. We describe and name this anatomical landmark as junctio circularis alba or the "circular junction of the LA" as encountered in normal adult human anatomy. We believe this is crucial for describing key surgical procedures at this site to aid effective surgical training and reduce iatrogenic complications from laparoscopic port site entries.

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.

Morphological changes of the lateral abdominal muscles in adolescent soccer players with low back pain: A prospective cohort study.

BACKGROUND: Most papers examining the lateral abdominal muscles (LAMs) and low back pain (LBP) are cross-sectional, with groups of participants being divided into a control and an LBP group. We hypothesized that morphological measurements of the LAMs in adolescent soccer players may predict future LBP incidence. The aim of this study was to examine the associations between the morphology of LAMs and LBP incidence rate among adolescent soccer players. METHODS: Ninety-seven adolescent male soccer players with no LBP at baseline were recruited into the prospective cohort study. The thickness of the LAMs was measured at baseline by ultrasound imaging in a supine rest position. Nine cases of LBP occurred during the follow-up 6-month observation. RESULTS: An obliquus internus (OI) asymmetry was related to increasing LBP risk (odds ratio = 19.99; 95%CI: 2.4-167.9). Spearman correlation also showed a linear relationship between OI asymmetry value and duration of LBP (R = 0.75, p = 0.02). An OI side-to-side difference greater than 1.25 mm suggests possible LBP incidence in the 6-month observation among adolescent soccer players. CONCLUSION: The morphological changes of the OI may be related to LBP's incidence in adolescent soccer players. The presence of OI asymmetry increases the odds of LBP by at least 2.4 times. Hypertrophy of the OI on one side of the body may contribute to trunk muscle imbalance.

Myology of juvenile freshwater prawn Macrobrachium amazonicum (Decapoda, Caridea): Morphology and swimming implication.

Little is known about the functional morphology of locomotion in prawns, and even fewer studies have succeeded in relating a specific muscular group to the movement of the body. The present study aimed to describe the morphology of the thoracoabdominal muscle system and its implications for swimming in juveniles of Macrobrachium amazonicum. Ten muscles were observed in the abdominal muscular system in juveniles of M. amazonicum. The complex arrangement of the anterior oblique muscle in association with the central muscles occupies most of the abdominal space. This muscular compound could promote a flexion movement of the abdomen for body propulsion as well as the tail movement during swimming. Morphofunctional continuity between thoracic and abdominal muscles could aid in locomotion and support the abdominal movement. Moreover, collagen plays a valuable role in connecting deep muscles not inserted in the carapace. Collagenous fascia could transmit the tension during the contraction of deep muscles for coordinated movement.

Clinically Differentiated Abnormalities of the Architecture and Expression of Myosin Isoforms of the Human Cremaster Muscle in Cryptorchidism and Retractile Testis.

AIM: To describe architecture and expression of myosin isoforms of the human cremaster muscle (CM) and to individuate changes in clinically differentiated abnormalities of testicular descent: cryptorchidism or undescended testis (UDT) and retractile testis (RT). BACKGROUND: The CM is a nonsomitic striated muscle differentiating from mesenchyme of the gubernaculum testis. Morphofunctional and molecular peculiarities linked to its unique embryological origin are not yet completely defined. Its role in abnormalities of testicular descent is being investigated. SUBJECTS AND METHODS: Biopsy samples were obtained from corrective surgery in cases of cryptorchidism, retractile testis, inguinal hernia, or hydrocele. Muscle specimens were processed for morphology, histochemistry, and immunohistology. RESULTS AND CONCLUSIONS: The CM differs from the skeletal muscles both for morphological and molecular characteristics. The presence of fascicles with different characterization and its myosinic pattern suggested that the CM could be included in the specialized muscle groups, such as the extrinsic ocular muscles (EOMs) and laryngeal and masticatory muscles. The embryological origin from the nonsomitic mesoderm is, also for the CM, the basis of distinct molecular pathways. In UDT, the histological alterations of CM are suggestive of denervation; the genitofemoral nerve and its molecular messengers directed to this muscle are likely defective. Compared with the other samples, RT has a distinct myosinic pattern; therefore, it has been considered a well-defined entity with respect to the other testicular descent abnormalities.

Core muscles thickness is not associated with knee frontal plane projection angle during single-leg squat in healthy people.

BACKGROUND: Core muscles play an important role in lower limb stability and alignment, with their weakness being associated with poor alignment and, consequently, with injuries. Despite muscle structure being critical to muscle strength production, we did not find studies associating the morphology of the core muscles and lower limb alignment during functional tasks. RESEARCH QUESTION: Is there association between thickness of core muscles (external oblique - EO, internal oblique - IO, transversus abdominis - TrA and gluteus medius - GMed) and lower limb alignment during the single-leg squat in healthy subjects? METHODS: Forty-six healthy participants (27 male and 19 female) performed the following evaluations: (i) measurements of muscle thickness of the EO, IO, TrA and GMed using ultrasound and (ii) measurements of lower limb alignment using the knee frontal plane projection angle (FPPA) during the single-leg squat. A Spearman rank correlation coefficient (rs) was performed between the thickness of selected core muscles (OE, OI, TrA and GMed) and the knee FPPA. In addition, a partial correlation (r) was performed, using sex, physical activity level and body mass index as control variables. RESULTS: We did not observe significant correlations between the knee FPPA and the thickness of the EO (rs = 0.194; p = 0.197), IO (rs = 0.182; p = 0.225), TrA (rs = 0.073; p = 0.627) and GMed (rs = -0.092; p = 0.542). When controlling for sex, physical activity level and body mass index, similar results were observed [EO (r = 0.157; p = 0.316), IO (r = 0.261; p = 0.092), TrA (r = 0.030; p = 0.850) and GMed (r = -0.144; p = 0.356)] SIGNIFICANCE: Our results demonstrated that core muscles' thickness is not associated with lower limb alignment during the single-leg squat in healthy people.

Hypertrophy of Lumbopelvic Muscles in Inactive Women: A 36-Week Pilates Study.

BACKGROUND: The use of Pilates in various fields of sport sciences and rehabilitation is increasing; however, little is known about the muscle adaptations induced by this training method. HYPOTHESIS: A standardized Pilates training program for beginners (9 months; 2 sessions of 55 minutes per week) will increase the muscle volume and reduce potential side-to-side asymmetries of the quadratus lumborum, iliopsoas, piriformis, and gluteus muscles (gluteus maximus, medius, and minimus). STUDY DESIGN: Controlled laboratory study. LEVEL OF EVIDENCE: Level 3. METHOD: A total of 12 inactive, healthy women (35.7 ± 5.4 years) without previous experience in Pilates were randomly selected to participate in a supervised Pilates program (36 weeks, twice weekly). Muscle volume (cm3) was determined using magnetic resonance imaging at the beginning and end of the intervention program. Side-to-side asymmetry was calculated as [(left - right volume) × 100/right volume]. RESULTS: Small, nonsignificant (P > 0.05) differences in the volume of the quadratus lumborum, iliopsoas, piriformis, and gluteus muscles were observed between pre- and post-Pilates program timepoints. Before and after Pilates, side-to-side asymmetry was less than 6% and nonsignificant in all muscles analyzed. CONCLUSION: Modern Pilates performed twice weekly for 9 months did not elicit substantial changes in the volume and degree of asymmetry of the selected lumbopelvic muscles in inactive women. CLINICAL RELEVANCE: The benefits of Pilates in rehabilitation or training are likely elicited by neuromuscular rather than morphological adaptations. Pilates has no significant impact on muscle volume and does not alter side-to-side ratios in muscle volume (degree of asymmetry) of the lumbopelvic muscles.

The Effect of Additional External Resistance on Inter-Set Changes in Abdominal Muscle Thickness during Bridging Exercise.

Bridging exercises with abdominal hollowing are often used as a regimen for improving spinal stability. Lately, this type of training has become very popular among elite athletes, creating a need for more demanding exercises. The purpose of this study was to investigate whether the use of additional external resistance is beneficial for abdominal muscle recruitment during bridge exercise. Tissue movement of the transversus abdominis (TrA) and the rectus abdominis (RA) was recorded with the use of two synchronized ultrasonic devices, in 20 healthy college students. From the hook-lying position participants were examined in eight different exercise conditions: a) rest, b) abdominal drawing-in maneuver (ADIM), c) bridge, d) bridge- ADIM, e) bridge with 10KG, f) bridge- ADIM with 10KG, g) bridge with 20KG and h) bridge-ADIM with 20KG. Analysis of variance (ANOVA) showed a statistically significant increase in TrA thickness when performing the bridge exercise combined with ADIM compared to rest mode (p < .05). RA thickness decreased when the ADIM was performed, compared to rest (p < 0.05). No significant difference in TrA and RA thickness when exercising with and without external resistance was observed (p > 0.05). The main outcome of this study was that external loading provided some extra level of difficulty, yet it was not beneficial for abdominal muscle recruitment, when performing a supine bridge exercise.

Effect of neuromuscular electrical stimulation training for abdominal muscles on change of muscle size, strength, endurance and lumbopelvic stability.

BACKGROUND: Neuromuscular electrical stimulation (NMES) devices for abdominal muscles are being marketed to the general public to improve physical appearance. Abdominal muscles play an important role in lumbopelvic stability for optimizing performance. We investigated the effects of NMES training of abdominal muscles on muscle size, muscle strength, endurance, and lumbopelvic stability. METHODS: Twenty-three subjects (12 females, 11 males) performed abdominal muscle NMES training for 8 weeks. Before and after NMES training, we measured muscle size (cross-sectional area [CSA] of the rectus abdominals [RA] and lateral abdominal wall [LAW]) by magnetic resonance imaging, muscle strength (trunk flexor and side bridge strength), endurance (trunk flexor and side bridge endurance time), and lumbopelvic stability (one-leg loading test). RESULTS: There were significant increases between pre- and post-NMES training differences in the size (CSA of RA 21.7-25.4%, P<0.001; CSA of LAW 9.00-9.71%, P<0.001), strength (trunk flexor 14.9%, P<0.05; side bridge 33.7-53.6%, P<0.05), and endurance (trunk flexor 29.1%, P<0.05; side bridge 24.6-28.9%, P<0.05) of abdominal muscles and lumbopelvic stability (37.2-37.4%, P<0.05). CONCLUSIONS: NMES training could be applied to increase muscle size and muscle performances of abdominal muscles in sports and fitness fields.

Intraoperative Observation during Total Extraperitoneal Repair (TEP).

We aim to observe and dissect the essential anatomical landmarks in totally extraperitoneal (TEP) procedures. Forty-six TEP procedures in 30 patients were prospectively performed in our department. During the dissection of the preperitoneal space, the following distances between landmarks were measured. D1: the distance from pubic symphysis to the arcuate line in the midline; D2: the distance from the inferior epigastric artery to the lateral border of the arcuate line (before sharp incision was performed); D3: as in D2 (but after sharp incision was performed); D4: the distance from the inferior epigastric artery to the crossing site of vas deferens and obliterated umbilical artery. Furthermore, the morphology of the posterior rectus sheath was documented. The corresponding distance between the anatomical landmarks varied greatly in each individual. D1: 8 ± 1.6 cm (range 4-10 cm). D2: 4.9 ± 0.8 cm (3.5-7 cm). D3: 6.8 ± 0.9 cm (5-9 cm). D4: 6.1 ± 1 cm (4.8-8.5 cm). Complete rectus sheath was found in 30.4 per cent (14/46) of the hernias. Anatomical variations were common in preperitoneal space. The crossing site of vas deferens and obliterated umbilical artery can serve as a landmark for dissection. Complete rectus was present in one-third of hernias, which necessitates a sharp incision for entering the correct lateral preperitoneal space.

Abdominal wall morphometric variability based on computed tomography: Influence of age, gender, and body mass index.

INTRODUCTION: Ventral hernia surgery does not usually account for the individuality of the abdominal wall anatomy. This could be both because medical imaging is rarely performed before surgery and because data on abdominal wall variability are limited. The objective of the present study was to perform an exhaustive morphometric analysis of abdominal wall components based on computed tomography (CT) scans. MATERIALS AND METHODS: A retrospective study was performed on 120 abdominopelvic CT scans of clinically normal adults aged 18-86 years equally divided between women and men and into four age groups. Each abdominal wall muscle was evaluated in terms of area, thickness, shape ratio, fat infiltration, and aponeuroses width. The influence of age, gender, and body mass index (BMI) was investigated, as well as muscular asymmetry. RESULTS: The abdominal wall muscle area represented 8.5 ± 2.5% of the abdominal area. The internal oblique muscle had the largest area, the rectus abdominis was the thickest, the transversus abdominis was the narrowest and had the smallest area. The width of the linea alba was 20.3 ± 12.0 mm. The evolution of the abdominal wall with age was quantified, as well as the large differences between the sexes and BMI groups, resulting in strong correlations and highlighting the specific pattern of the transversus abdominis. The asymmetry of the left and right muscle areas oscillated around 17%. CONCLUSIONS: The various components of the abdominal wall have been precisely described. Knowledge of their variability could be used to enhance the planning of ventral hernia surgery or to develop numerical modeling of the abdominal wall.

Original concepts in anatomy, abdominal-wall surgery, and component separation technique and strategy.

BACKGROUND: The abdominal wall can be considered comprised of two compartments: an anterior and a posterior compartment. The anterior compartment includes the anterior rectus sheath and the rectus muscle. The posterior compartment comprises the posterior rectus sheath, the transversalis fascia, and the peritoneum. When a large defect in the anterior compartment has to be corrected, for example, a rectus diastasis or large incisional hernia, an action on the anterior compartment is necessary; therefore, an anterior component separation has to be considered. If a loss of substance is present in the posterior compartment, a trasversus abdominis release should be accomplished. METHODS: We propose an original anterior compartment mobilisation, by a posterior approach. Dissection of the posterior rectus sheet proceeds until the linea semilunaris is reached. Incision of the anterior rectus sheath permits a mobilisation of the anterior compartment by a posterior approach. A mesh is placed in a sublay position. If the abdominal wall presents a loss of substance of the posterior compartment, a transversus abdominis release (TAR) can be performed in the same time. RESULTS: No hernia recurrences, no wound infection, and no mesh infection have been reported. CONCLUSIONS: The anterior compartment mobilization permits mobilization towards the midline of rectus muscle and restoration of anterior compartment, with low morbidity rate; it can be easily associated to a large sublay mesh placement, it allows the preservation of the neurovascular bundles and rectus muscle trophism, and it can be associated with a concomitant TAR procedure for the restoration of the PC, if necessary.