Embryonic developmental process and clinical anatomy of the preperitoneal fascia and its clinical significance.

PURPOSE: Many researchers have different views on the origin and anatomy of the preperitoneal fascia. The purpose of this study is to review studies on the anatomy related to the preperitoneal fascia and to investigate the origin, structure, and clinical significance of the preperitoneal fascia in conjunction with previous anatomical findings of the genitourinary fascia, using the embryogenesis of the genitourinary system as a guide. METHODS: Publications on the preperitoneal and genitourinary fascia are reviewed, with emphasis on the anatomy of the preperitoneal fascia and its relationship to the embryonic development of the genitourinary organs. We also describe previous anatomical studies of the genitourinary fascia in the inguinal region through the fixation of formalin-fixed cadavers. RESULTS: Published literature on the origin, structure, and distribution of the preperitoneal fascia is sometimes inconsistent. However, studies on the urogenital fascia provide more than sufficient evidence that the formation of the preperitoneal fascia is closely related to the embryonic development of the urogenital fascia and its tegument. Combined with previous anatomical studies of the genitourinary fascia in the inguinal region of formalin-fixed cadavers showed that there is a complete fascial system. This fascial system moves from the retroperitoneum to the anterior peritoneum as the preperitoneal fascia. CONCLUSIONS: We can assume that the preperitoneal fascia (PPF) is continuous with the retroperitoneal renal fascia, ureter and its accessory vessels, lymphatic vessels, peritoneum of the bladder, internal spermatic fascia, and other peritoneal and pelvic urogenital organ surfaces, which means that the urogenital fascia (UGF) is a complete fascial system, which migrates into PPF in the preperitoneal space and the internal spermatic fascia in the inguinal canal.

Estudo experimental comparativo da resistência tensional da safena magna no tornozelo e na região inguinal / Experimental comparative assay of tensile resistance of greater saphenous vein from ankle and groin

Resumo Contexto A veia safena magna é usada como material de remendo em vários tipos de reconstrução arterial, incluindo no trauma e endarterectomias de carótida e femoral. Houve relatos de ruptura do remendo de safena, particularmente de veias colhidas na região do tornozelo. Há uma necessidade de medição objetiva da resistência tecidual da safena magna. Objetivos Mensurar a força tensional suportada pela veia safena magna e analisar a correlação entre resistência e diâmetro da veia. Métodos As veias foram coletadas durante operações de safenectomia por varizes dos membros inferiores. Foram analisados apenas segmentos sem refluxo. Foram analisados 10 membros de oito pacientes, com um total de 20 espécimes. Os espécimes foram submetidos a ensaio de tração em equipamento eletrônico, obtendo-se os valores de tensão máxima do material em quilogramas-força por centímetro quadrado (kgf/cm2; força máxima dividida pela área de secção transversa do segmento submetido à tração). Resultados A tensão máxima suportada pela veia safena do tornozelo variou de 74,02 a 190,10 kgf/cm2, e a tensão máxima da veia safena da crossa variou de 13,53 a 69,45 kgf/cm2 (p < 0,0001). O coeficiente de correlação de Pearson entre o diâmetro da veia distendida e a tensão máxima suportada foram iguais a -0,852 (correlação inversa moderada a forte). Conclusões A resistência tecidual da veia safena magna do tornozelo é maior do que a da crossa em mulheres submetidas a operação de varizes; há correlação negativa entre o diâmetro da veia e sua resistência tecidual nessa mesma população.

Abstract Background The great saphenous vein is used as patch material in several types of arterial reconstruction, including trauma and carotid and femoral endarterectomy. There have been reports of saphenous patch blowout, particularly of patches constructed with veins harvested from the ankle. There is a need for objective measurement of the resistance of saphenous vein tissues. Objectives To measure the tensile strength of the great saphenous vein harvested at the ankle and groin and analyze the correlation between diameter and tissue strength. Methods Venous samples were harvested during elective saphenous stripping in patients with symptomatic varicose veins. Only segments without reflux were included. Ten limbs from eight patients were studied, providing 20 samples in total. Venous segments were opened along their longitudinal axis and fitted to electronic traction assay equipment to obtain values for material maximum tension in kilograms-force per square centimeter (kgf/cm2; the maximum force resisted by the segment, divided by its cross-sectional area). Results The average maximum tension in the ankle saphenous vein group ranged from 74.02 to 190.10 kgf/cm2 and from 13.53 to 69.45 kgf/cm2 in the groin saphenous vein group (p < 0.0001). The Pearson coefficient for the correlation between vein diameter and maximum tension was -0.852 (moderate to strong inverse correlation). Conclusions Ankle saphenous vein tissue from female patients operated for varicose veins has significantly higher resistance than saphenous vein tissue from the groin and there is an inverse relation between vein diameter and resistance of tissue from the same population.

Evaluating a low-fidelity inguinal canal model.

PURPOSE: The inguinal canal anatomy is of paramount clinical significance due to the common occurrence of direct and indirect inguinal hernias. However, the inguinal canal is often an area of great difficulty for medical students to understand. The aim of this study was to evaluate the use of a low-cost, low-fidelity inguinal canal model as a teaching and learning aid. METHODS: A low-fidelity inguinal canal model was introduced as a learning aid in an anatomy tutorial on the inguinal region. Students were randomised into intervention (n = 66) and control (n = 40) groups. Following the tutorial, all students completed a multiple-choice question quiz on the inguinal canal. The intervention group also completed a questionnaire evaluating the positive and negative aspects of the model. RESULTS: Students taught with the inguinal canal model achieved higher scores (mean: 88.31% vs 81.7%, p = 0.087). Positive aspects of the model as described by the students included its simplicity and ability to improve their three-dimensional understanding of the inguinal canal. Students requested more hands-on time with the model during the tutorial. CONCLUSION: The present study supports current literature in that low-fidelity anatomy models are a useful adjunct to aid students' learning of complex anatomical concepts. Students may benefit from creating their own inguinal canal model to retain as a personal study tool.

Schwann cell-specific Pten inactivation reveals essential role of the sympathetic nervous system activity in adipose tissue development.

There is increasing evidence that the sympathetic nervous system (SNS) plays an important role in adipose tissue development. However, the underlying molecular mechanism(s) associated with this remains unclear. SNS innervation of white adipose tissue (WAT) is believed to be necessary and sufficient to elicit WAT lipolysis. In this current study, mice with Schwann cell (SC)-specific inactivation of phosphatase and tensin homolog (Pten) displayed enlarged inguinal white adipose tissue (iWAT). This serendipitous observation implicates the role of SCs in mediating SNS activity associated with mouse adipose tissue development. Mice with SC-specific Pten inactivation displayed enlarged iWAT. Interestingly, the SNS activity in iWAT of SC-specific Pten-deficient mice was reduced as demonstrated by decreased tyrosine hydroxylase (TH) expression level and neurotransmitters, such as norepinephrine (NE) and histamine (H). The lipolysis related protein, phosphorylated hormone sensitive lipase (pHSL), was also decreased. As expected, AKT-associated signaling pathway was hyperactivated and hypothesized to induce enlarged iWAT in SC-specific Pten-deficient mice. Moreover, preliminary experiments using AKT inhibitor AZD5363 treatment ameliorated the enlarged iWAT condition in SC-specific Pten-deficient mice. Taken together, SCs play an essential role in the regulation of SNS activity in iWAT development via the AKT signaling pathway. This novel role of SCs in SNS function allows for better understanding into the genetic mechanisms of peripheral neuropathy associated obesity.

Lesiones inguinales pediátricas: hallazgos radiológicos / Pediatric groin lesions: imaging findings

OBJETIVOS: La región inguinal es un área anatómica compleja que ha sido tradicionalmente olvidada por los radiólogos dado que la mayoría de las lesiones pueden diagnosticarse mediante datos clínicos y con la exploración física. No obstante, cada vez es más frecuente la solicitud de ecografías, bien para confirmar la existencia de patología o para resolver casos dudosos. Por otra parte, la patología inguinal incluye entidades únicas de la edad infantil. El objetivo de este trabajo es describir los hallazgos radiológicos clave de las lesiones inguinales pediátricas, poniendo especial énfasis en los datos ecográficos CONCLUSIONES: El conocimiento de la patología inguinal pediátrica y sus claves en imagen ayudan a mejorar el rendimiento diagnóstico de la ecografía

OBJECTIVES: The groin is a complex anatomic region that has traditionally been ignored by radiologists because most lesions can be diagnosed from clinical data and physical examination. Nevertheless, ultrasound examinations of the groin are increasingly being requested to confirm injury or to resolve diagnostic uncertainty. On the other hand, some conditions involving the groin are found only in pediatric patients. This article describes the key imaging findings in pediatric groin injuries, placing special emphasis on the ultrasound appearance. CONCLUSIONS: Knowledge about conditions that can affect the groin in pediatric patients and the key imaging findings associated with them helps improve the diagnostic performance of ultrasound

Inguinal Subcutaneous White Adipose Tissue (ISWAT) Transplantation Model of Murine Islets.

Pancreatic islet transplantation is a well-established therapeutic treatment for type 1 diabetes. The kidney capsule is the most commonly used site for islet transplantation in rodent models. However, the tight kidney capsule limits the transplantation of sufficient islets in large animals and humans. The inguinal subcutaneous white adipose tissue (ISWAT), a new subcutaneous space, was found to be a potentially valuable site for islet transplantation. This site has better blood supply than other subcutaneous spaces. Moreover, the ISWAT accommodates a larger islet mass than the kidney capsule, and transplantation into it is simple. This manuscript describes the procedure of mouse islet isolation and transplantation in the ISWAT site of syngeneic diabetic mouse recipients. Using this protocol, murine pancreatic islets were isolated by standard collagenase digestion and a basement membrane matrix hydrogel was used for fixing the purified islets in the ISWAT site. The blood glucose levels of the recipient mice were monitored for more than 100 days. Islet grafts were retrieved at day 100 after transplantation for histological analysis. The protocol for islet transplantation in the ISWAT site described in this manuscript is simple and effective.

Pediatric groin lesions: imaging findings. / Lesiones inguinales pediátricas: hallazgos radiológicos.

OBJECTIVES: The groin is a complex anatomic region that has traditionally been ignored by radiologists because most lesions can be diagnosed from clinical data and physical examination. Nevertheless, ultrasound examinations of the groin are increasingly being requested to confirm injury or to resolve diagnostic uncertainty. On the other hand, some conditions involving the groin are found only in pediatric patients. This article describes the key imaging findings in pediatric groin injuries, placing special emphasis on the ultrasound appearance. CONCLUSIONS: Knowledge about conditions that can affect the groin in pediatric patients and the key imaging findings associated with them helps improve the diagnostic performance of ultrasound.

The fascial connections of the pectineal ligament.

In clinical settings, the pectineal ligament forms a basic landmark for surgical approaches. However, to date, the detailed fascial topography of this ligament is not well understood. The aim of this study was to describe the morphology of the pectineal ligament including its fascial connections to surrounding structures. The spatial-topographical relations of 10 fresh and embalmed specimens were dissected, stained, slice plastinated, and analyzed macroscopically, and in three cases histological approaches were also used. The pectineal ligament is attached ventrally and superiorly to the pectineus muscle, connected to the inguinal ligament by the lacunar ligament and to the tendinous origin of rectus abdominis muscle and the iliopubic tract. It forms a site of origin for the internal obturator muscle, and throughout its curved course, the ligament attaches to both the fasciae of iliopsoas and the internal obturator muscle. However, dorsally, these fasciae pass free from the bone, while the pectineal ligament itself is adhered to it. The organ fasciae are seen apart from the pectineal ligament and its connections. The pectineal ligament seems to form a connective tissue junction between the anterior and medial compartment of the thigh. This ligament, however, is free to other compartments arisen from the embryonal gut and to the urogenital ridge. These features of the pectineal ligament are important to consider during orthopedic and trauma surgical approaches, in gynecology, hernia and incontinence surgery, and in operations for pelvic floor and neovaginal reconstructions. Clin. Anat. 32:961-969, 2019. © 2019 Wiley Periodicals, Inc.

Age-related changes in inguinal region anatomy from 0 to 19 years of age.

Knowledge of the age-related changes in inguinal region anatomy is essential in pediatric urological and abdominal surgery, yet little is published. This study aimed to determine the position of inguinal region structures and growth of the surrounding pelvis and inguinal ligament in subjects from 0 to 19 years of age. Anonymized contrast-enhanced CT DICOM datasets of 103 patients (63 male: 40 female) aged from 0 to 19 years had left and right sides analyzed by three independent observers. Exclusion criteria were applied. Growth of the pelvis and inguinal ligament were determined using fixed bony reference points. The position of the deep inguinal ring and femoral vasculature were determined as ratio of inguinal ligament length, measured from the anterior superior iliac spine. Growth of the pelvis in vertical and horizontal dimensions and of the inguinal ligament followed a positive polynomial relationship with increasing age, with no observed increase in growth rate during puberty. From 0 to 19 years, the deep inguinal ring moved superolaterally with respect to the inguinal ligament (from 0.74 to 0.60 of the distance along the inguinal ligament) and the femoral artery and vein moved medially (from 0.50 to 0.58, and 0.61 to 0.65 of the distance along the inguinal ligament, respectively). The position of the femoral artery, vein, and deep inguinal ring followed a logarithmic relationship with age. No significant left:right side or male:female differences were observed. From 0 to 19 years of age the femoral vasculature and deep inguinal ring change position as the pelvis grows around them. Clin. Anat. 32:794-802, 2019. © 2019 Wiley Periodicals, Inc.

Close relationship between the short round ligament and the ovarian prolapsed inguinal hernia in female infants.

PURPOSE: The aim of this study was to clarify the relationship between the length of the round ligament and the presence of a patent processus vaginalis (PV) based on the hypothesis that a short round ligament is the cause of ovarian inguinal hernia in female infants. METHODS: Between April 2011 and March 2017, 132 girls underwent laparoscopic surgery for inguinal hernia. Before surgery, the presence of ovarian prolapse was diagnosed. We observed the internal inguinal ring laparoscopically and examined the diameter of the PV orifice as well as the round ligament length. Medical records and video records were reviewed to evaluate PV patency and round ligament length. RESULTS: Seventeen of the 132 cases had an ovarian inguinal hernia; all of them were infants. In all infants, with or without a prolapsed ovary, the round ligament was short, causing the ovary and fallopian tube to be close to the hernia orifice over the pelvic brim. In girls aged over 12 months, the round ligament lengths on the hernia side, contralateral open PV side, and contralateral closed PV side were 33.0 ± 9.3, 36.8 ± 7.5, and 41.4 ± 8.5 mm, respectively. The round ligament length in open PV was significantly shorter than in the closed PV, but the difference was smaller in older patients. CONCLUSION: The round ligament, which is the female gubernaculum in the fetus, was shorter in the open PV than in the closed PV in younger girls. The short round ligament results in the ovarian prolapsed hernia.

The round ligament of the uterus: Questioning its distal insertion.

PURPOSE: Classically, the round ligament of the uterus (RLU) attaches distally in the ipsilateral labia majora. This attachment has rarely been described in adults. That is why we have performed an anatomical study focused on this distal ending. PATIENTS: We performed in 2015 the cadaveric dissection of 19 RLU. METHODS: In all cases, the RLU was individualized on its entire length from its uterine origin to the inguinal canal. Then this canal was open from its internal orifice to its external orifice. We described the distal attachment of the RLU according four areas: before the internal inguinal ring, after the external inguinal ring, under the pubic bone and in labia majora. RESULTS: We found 3 types of distal attachments with first an attachment after the external inguinal ring in more than half of cases (52.6%). Then, before the internal inguinal ring (26.3%) and under the pubic bone (22.1%). No RLU was found inlabia majora. However, the proximal attachment seems constant at the antero-superior face of uterus, near the tubo-uterine junction like its pelvic path under the broad ligament. CONCLUSION: In adult, the RLU is a structure, which begins at the cranio-ventral part of the uterine bottom near the tubo-uterine junction. Then it passes under the broad ligament and reaches the inguinal canal, that it crosses in more half of cases. However, 3 distal attachment areas have been identified but never in the labia majora. Indeed, some anatomical information available in anatomical treaties seems not correct and should be amended.

Evaluation of hernia of the male inguinal canal: sonographic method.

Sonography of the male inguinal canal for hernia is a common request. There is debate about the accuracy and even need for sonographic assessment of inguinal hernia. A clear, concise method is presented, with correlated diagrams and sonographic images, which aims to improve the ability of sonographers to easily identify inguinal herniae.

Anatomy and pathology of the canal of Nuck.

The canal of Nuck is the female equivalent of the processus vaginalis in the male but is less well known than its male counterpart. It is a rare entity not commonly encountered by radiologists, particularly in the adult population. Knowledge of the embryology and anatomy of the canal of Nuck is essential for identification of the various pathologic conditions that may occur in this location. Moreover, radiologists should be familiar with this entity to compose an appropriate and thorough differential diagnosis of a labial mass/swelling. In this review, we discuss both the anatomy and the more common pathology that can be encountered within it.

Absent external oblique musculo-aponeurotic complex during inguinal hernioplasty: a case report and review of literature.

The external oblique musculo-aponeurotic complex is an important contributor to the strength of the inguinal canal. The present case report describes the bilateral absence of the external oblique muscle in a patient. A 40-year-old male patient presented with a history of intermittent lower abdominal pain for 15 years which had increased over the past 2 years. Abdominal examination revealed bilateral reducible, incomplete, direct inguinal hernia. Elective bilateral Lichtenstein's mesh hernioplasty was planned for the patient. Intraoperatively, there was no evidence of the external oblique aponeurosis and the spermatic cord was noted deep to the membranous fascial layer. The inguinal ligament was thin and atrophic and was attached to the pubic tubercle medially and anterior superior iliac spine laterally. There was no evidence of any superior aponeurotic connection to the inguinal ligament. A postoperative ultrasound examination of the abdomen confirmed the bilateral absence of the external oblique musculo-aponeurotic complex. The isolated absence of the external oblique musculo-aponeurotic complex in adults is an exceedingly rare anomaly. The possibility of such an anomaly should be considered in patients without other risk factors for hernia.

BMP4 mediates the interplay between adipogenesis and angiogenesis during expansion of subcutaneous white adipose tissue.

The expansion of subcutaneous (SC) white adipose tissue (WAT) has beneficial effects on metabolic health. Our previous work showed an increased number of bone morphogenetic protein 4 (BMP4)-activated beige adipocytes in SC WAT, indicating a potential role of BMP4 in adipocyte recruitment. It was also demonstrated that BMP4 committed multipotent mesodermal C3H10T1/2 stem cells to the adipocyte lineage ex vivo However, the mechanism by which BMP4 regulates adipogenesis in vivo has not been clarified. In this study, we found that BMP4 stimulated de novo adipogenesis in SC WAT concomitant with enhanced blood vessel formation, thus promoting adipose tissue angiogenesis. Platelet-derived growth factor receptor-ß-positive (PDGFRß(+)) multipotent stem cells within the neoangiogenic vessels were found to be adipocyte progenitors. Moreover, BMP4 downregulated PDGFRß by stimulating the lysosome-dependent degradation, which efficiently initiated adipogenic differentiation. These results suggest how BMP4 regulates adipocyte recruitment in SC WAT, and thus promote its beneficial metabolic effects.

Consideraciones Anatomo-Quirúrgicas del Ligamento Reflejo / Reflected Ligament: Anatomical and Surgical Considerations

La anatomía de la región inguinal está bien descrita y detallada en la literatura, pero existen algunas controversias vinculadas al ligamento reflejo y a su inserción medial. El objetivo fue analizar la inserción del ligamento inguinal reflejo del músculo oblicuo externo en la línea alba, mediante lo observado en disecciones cadavéricas. Se utilizaron 30 cadáveres formolizados, en los que el ligamento reflejo fue disecado hasta su inserción en la línea alba. Se encontró la presencia del ligamento inguinal reflejo en 25 (83,33%) casos, 16 (64%) hombres y 9 (36%) mujeres, de los cuales sólo en 2 (8%) casos se observó la inserción interdigitada del ligamento inguinal reflejo con el contralateral; y en 5 (16,67%) casos (3 mujeres y 2 hombres), se constató ausencia del mencionado ligamento. El ligamento reflejo fue identificado en la mayoría de nuestros ejemplares. Este ligamento contribuye a la formación de la pared posteromedial del anillo inguinal superficial, siendo importante la necesidad de su conocimiento anatómico para su aplicación en la reparación quirúrgica de hernias inguinales con colocación protésica por vía anterior.

Anatomy of the inguinal region is well described in literature, but there is lack of information related to the reflected ligament and a dichotomy regarding its medial insertion. The aim was to carry out an observational analysis, through dissections, of the insertion of the reflected ligament of the external oblique muscle at the linea alba. We used 30 formolized corpses were, on which the reflected ligament was dissected to its insertion into the linea alba. Of the 30 bodies, we found the reflected ligament in 25 (83.33%), being 16 male (64%) and 9 females (36%), but only in 2 of them (8%) its insertion interdigitated with the contralateral. In 5 (16.67%) cases, 3 female (60%) and 2 male (40%), the absence of that ligament was found. The reflected ligament was identified in most of our specimens. Being part of the posterior limit of the superficial inguinal ring, its anatomical knowledge is important for the surgical repair of inguinal hernias with prosthetic placement, using anterior access.