Anatomy of the pudendal nerve in clinically important areas: a pictorial essay and narrative review.

PURPOSE: The pudendal nerve is an anatomical structure arising from the ventral branches of the spinal roots S2-S4. Its complex course may be affected by surrounding structures. This may result in irritation or entrapment of the nerve with subsequent clinical symptoms. Aim of this study is to review the anatomy of the pudendal nerve and to provide detailed photographic documentation of the areas with most frequent clinical impact which are essential for surgical approach. METHODS: Major medical databases were searched to identify all anatomical studies investigating pudendal nerve and its variability, and possible clinical outcome of these variants. Extracted data consisted of morphometric parameters, arrangement of the pudendal nerve at the level of roots, formation of pudendal nerve, position according to sacrospinal and sacrotuberal ligaments and its terminal branches. One female cadaver hemipelvis was dissected with common variability of separate course of inferior rectal nerve. During dissection photodocumentation was made to record course of pudendal nerve with focus on areas with recorded pathologies and areas exposed to iatrogenic damage during surgical procedures. RESULTS: Narrative review was done to provide background for photodocumentation. Unique photos of course of the pudendal nerve was made in areas with great clinical significance. CONCLUSION: Knowledge of anatomical variations and course of the pudendal nerve is important for examinations and surgical interventions. Surgically exposed areas may become a site for iatrogenic damage of pudendal nerve; therefore, unique picture was made to clarify topographic relations.

Anatomical Relationships of the Sciatic Nerve and Pudendal Nerve to the Ischial Spine as They Exit the Greater Sciatic Foramen.

OBJECTIVE: Deep gluteal syndrome is a clinical condition in which discomfort may arise due to the pathoanatomy of the subgluteal space. We conducted an anatomical exploration to categorize the relationship of the piriformis muscle, sciatic nerve (SN), and pudendal nerve (PN) to the ischial spine (IS) and sacrospinous ligament. METHODS: We analyzed 22 cadavers. The piriformis muscle, SN, and PN were exposed through either a transgluteal approach or a gluteal flap. The relationship of the neural structures to the IS, sacrospinous ligament, and ischial bone as they exit the greater sciatic foramen was observed, and the exit zones were classified as zone A, medial to the IS (entirely on sacrospinous ligament); zone B, on the IS; and zone C, lateral to the IS (entirely on ischial bone). RESULTS: The SN was observed either in zone B or zone C in all specimens. The PN was found to be in either zone A or zone B in 97.6% of specimens. The most common combinations were SN in zone B and PN in zone A (type I), and SN in zone C and PN in zone B (type II). CONCLUSIONS: The results from this study show clear anatomical differences in the SN-PN relationship, which may play a role in pain seen in deep gluteal syndrome. Moreover, classification of the SN-IS and PN-IS relationships described in this article will help describe different pathologies affecting the deep gluteal area.

Bloqueos Nerviosos. Bases Anatómicas del Dolor Somático Abdomino-Pélvico / Nerve Blocks. Anatomy of the Somatic Innervation of the Abdomino-Pelvic Cavity

El dolor abdominal es una de las sintomatologías que afectan con frecuencia la cavidad abdomino-pélvica. Dicha cavidad posee una inervación somática en la que intervienen del séptimo a doceavo nervios intercostales, ramos colaterales y terminales del plexo lumbar y el nervio pudendo; siendo objetivo de este trabajo la descripción anatómica del dolor abdominopélvico a través del plexo lumbar, nervios intercostales y nervio pudendo, sus diferentes patrones y variaciones de conformación, y las implicancias de éstas últimas en las distintas maniobras clínico-quirúrgicas. Se realizó un estudio descriptivo, observacional y morfométrico de la inervación somática de la cavidad abdomino-pélvica, en 50 preparaciones cadavéricas, fijadas en solución de formaldehído, de la Tercera Cátedra de Anatomía, Facultad de Medicina, Universidad de Buenos Aires, entre Agosto/2017-Diciembre/2019. La descripción clásica del plexo lumbar se encontró en 35 casos; la presencia del nervio femoral accesorio en ningún caso; así como también la ausencia del nervio iliohipogástrico en ningún caso; el nervio obturador accesorio se halló en 2 casos; el nervio genitofemoral dividiéndose dentro de la masa muscular del psoas mayor en 6 casos; el nervio cutáneo femoral lateral emergiendo únicamente de la segunda raíz lumbar en 6 casos y por último se encontró la presencia de un ramo del nervio obturador uniéndose al tronco lumbosacro en un caso. Los nervios intercostales y el nervio pudendo presentaron una disposición clásica en todos los casos analizados. Es esencial un adecuado conocimiento y descripción del plexo lumbar, nervios intercostales y nervio pudendo para un adecuado abordaje de la cavidad abdomino-pélvica en los bloqueos nerviosos.

SUMMARY: Abdominal pain is one of the symptoms that affect the abdominal-pelvic cavity. The abdominal-pelvic cavity has a somatic innervation involving the seventh to twelfth intercostal nerves, collateral and terminal branches of the lumbar plexus and the pudendal nerve. The objective of this work is the description of the lumbar plexus, intercostal nerves and pudendal nerve, its different patterns and structure variations, as well as its implications during pain management in patients. A descriptive, observational, and morphometric study of patterns and structure variations of the lumbar plexus, intercostal nerves and pudendal nerve was conducted in 50 formalin-fixed cadaveric dissections of the Third Chair of Anatomy at the School of Medicine in the Universidad de Buenos Aires from August 2017 to December/2019. The standard description of the lumbar plexus was found in 35 cases; accessory femoral nerve was not present in any of the cases; absence of the iliohipogastric nerve was also not found in any case, while the accessory obturating nerve was found in 2 cases; genitofemoral nerve dividing within the muscle mass of psoas in 6 cases; lateral femoral cutaneous nerve emerging only from the second lumbar root in 6 cases and finally, presence of a branch of the obturating nerve was found joining the lumbosacral trunk in one case. The pudendal and intercostal nerve patterns presented a typical pathway in all cases. Adequate knowledge and description of the lumbar plexus, intercostal nerves and pudendal nerve is essential for an adequate approach of the abdominal-pelvic cavity in nerve blocks.

Anatomical description of the perforating cutaneous nerve.

BACKGROUND: The perforating cutaneous nerve/perforating nerve of the sacrotuberous ligament is rarely observed. It usually arises from the posterior division of the sacral plexus or the pudendal nerve and perforates the sacrotuberous ligament. The anatomy of this nerve and its variants is poorly described in the literature, but there are data indicating its role in pudendal neuralgia. MATERIALS AND METHODS: Herein, we present an anatomical study of six formalin-fixed cadavers with descriptions of the topography of spinal nerves S2-S4, the pudendal bundle, the perforating cutaneous nerve and the sacrotuberous ligament. RESULTS: We found three perforating cutaneous nerves and described each of them in detail, with measurements of length and width, and point of perforation of the sacrotuberous ligament. CONCLUSIONS: We distinguished three types of perforating cutaneous nerve on the basis of our findings and previous publications; two of the three types were observed in our study.

Mapping a Danger Zone of the Dorsal Nerve of the Clitoris: Implications in Female Cosmetic Genital Surgery.

BACKGROUND: The literature regarding the route of the dorsal nerve of the clitoris is sparse and lacks surgical focus. With an increasing number of procedures being performed on the labia, it is important to elucidate the route and note any variation from normal of the nerve. METHODS: Fifty-one cadavers were dissected to yield 97 dorsal nerve of the clitoris samples. Measurements were taken from (1) the dorsal nerve of the clitoris penetration point of the perineal membrane to the urethra, (2) the nerve's penetration point of the perineal membrane to the pubic bone, (3) the angle of the clitoris to the branch point of the dorsal nerve of the clitoris, and (4) the branch point of the nerve to the distalmost point of the glans clitoris. Any anomalous branching patterns of the dorsal nerve of the clitoris were recorded and classified. RESULTS: The means and standard deviations of each measurement were used to create a surgical danger zone. The mean of each measurement was (1) 34.63 mm, (2) 5.74 mm, (3) -3.07 mm, and (4) 30.40 mm, respectively. In addition, six distinct branching patterns were observed, organized, and classified based on the location and number of branches observed. CONCLUSIONS: The dorsal nerve of the clitoris has multiple branching patterns and typically travels along the same course in most women. Further investigation of the course and three-dimensional position of the dorsal nerve of the clitoris is warranted to preserve sexual sensation as the frequency of procedures involving the female pudendum increases.

The Anatomical Distribution of the Pudendal Nerve Block Injection: A Cadaveric Study.

OBJECTIVE: The objective of this study was to assess the accuracy of commonly used injection locations of the pudendal nerve block by examining the proximity of the injected dye to the pudendal nerve in a cadaveric model. METHODS: Pudendal block injections at 4 sites were placed transvaginally on 5 cadaveric pelvises. These sites were 1 cm proximal to the ischial spine (black dye), at the ischial spine (red dye), 1 cm distal to the ischial spine (blue dye), and 2 cm lateral and 2 cm distal to the ischial spine (green dye). The cadavers were dissected via a posterior approach. RESULTS: We measured the shortest distance from the center of the dye-stained tissue to the pudendal nerve. As expected, the injections at the ischial spine (red) resulted in a distribution of dye closest to the pudendal nerve, averaging 3.0 ± 0.95 mm. Dyes at other sites were close to the nerve: 3.1 ± 1.00 mm (black), 3.6 ± 1.14 mm (blue), and 4.05 ± 1.28 mm (green). CONCLUSIONS: Regardless of the injection site, all dyes were close the pudendal nerve, indicating accuracy. We observed wide variation in the dye distribution even though all injections were performed by the same provider, implicating lack of precision. Based on our findings, we propose that the most effective injection location is at the ischial spine because it is the closest to the pudendal nerve; however, all injections were within 4 mm of the pudendal nerve, suggesting that only 1 to 2 injections may be sufficient.

Method of determining the location of the sexual neurovascular bundle (internal pudendal artery, internal pudendal vein and pudendal nerve) / Método para determinar la ubicación del haz neurovascular sexual (vena y arteria pudenda interna y nervio pudendo)

Disorders in the course of the neurovascular bed of the sexual neurovascular bundle (NVB) entail problems of gynecological, andrological and urological nature, for example, the state of impotence in men. The aim of the study was to establish a method to determine a projection. The Arteria pudenda interna, Vena pudenda interna and Nervus pudendus (sexual neurovascular bundle or NVB) from the infrapiriform foramen to the Alcock's canal (pudendal canal) in which the pudendal neurovascular bundle runs. Topographic and anatomical study was performed on 15 corpses without organ complex (remote shore): 9-from men and 6-women, aged 36 to 74 years. Each object of study (corpse) included 2 pairs of sexual NVB, a total of 30 investigated. The information obtained on the projection branches of the pudendal nerve, and pudendal internal artery and pudendal internal vein from infrapiriform foramen to the entrance of the pudendal canal. A method for determining the projection of sexual NVB in the gluteal region was developed. The projection of Arteria pudenda interna, Vena pudenda interna and Nervus pudendus from the infrapiriform foramen in the gluteal region and to the entrance of the pudendal canal is determined. The morphometric data necessary for the mathematical equation developed by us for the calculation of the boundaries of the projection of the desired plane in the course of the sexual NVB are obtained . Using these data in the method of mathematical calculation developed by us using the formula C'c' = 0,2679 x (A'G-AD+3), we determined the projection of the figure, in the form of a trapezoid, in the center of which the projection of the sexual NVB is determined.A method for determining the projection of the sexual neurovascular bundle in the gluteal region for diagnosis and therapeutic effects on sexual NPS was developed.

Los trastornos en el curso de las estructuras del haz neurovascular sexual conllevan problemas de naturaleza ginecológica, andrológica y urológica, por ejemplo, el estado de impotencia en los hombres. El objetivo de este estudio fue establecer un método para determinar una proyección de los vasos pudendos internos y el nervio pudendo (haz neurovascular sexual o HNV) desde el foramen infrapiriforme hasta el canal de Alcock (canal pudendo). Se realizó un estudio topográfico y anatómico en 15 cadáveres: 9 hombres y 6 mujeres, entre 36 y 74 años. Se analizaron 30 muestras, cada cadáver incluyó 2 pares de HNV sexuales. Se obtuvo información sobre las ramas de proyección de la arteria, y vena pudenda interna y del nervio pudendo, desde el foramen infrapiriforme hasta la entrada al canal pudendo. Se desarrolló un método para determinar la proyección de NVB sexual en la región glútea. La proyección de la vena pudenda interna y del nervio pudendo se determinó desde el foramen infrapiriformis en la región glútea, hasta la entrada del canal pudendo. Se obtuvieron datos morfométricos necesarios para la ecuación matemática y obtener el cálculo de los límites de la proyección del plano deseado en el curso de la HNV sexual. Usando estos datos se utilizó la fórmula C'c '= 0,2679 x (A'G-AD + 3), y se realizó la proyección de la figura, en forma de trapecio, en el centro del cual se determinó la proyección de la HNV sexual. Se desarrolló un método para la proyección del haz neurovascular sexual en la región glútea, en el diagnóstico y los efectos terapéuticos sobre el NPS sexual.

Pudendal Nerve Identified on Sectioned Images of Female Cadaveric Pelvis.

OBJECTIVE: To provide an anatomical atlas made of serially sectioned images of a female cadaver that clearly demonstrated the pudendal nerve. MATERIALS AND METHODS: The courses of the pudendal nerve, internal pudendal artery, and internal pudendal vein were observed on the sectioned images of a female cadaver. The spatial relationship between the nerve and blood vessels was interpreted. RESULTS: Traces of the structures on the sectioned images showed that the sources of the sciatic and pudendal nerves were the fourth lumbar nerve to the second sacral nerve and the second to the fourth sacral nerves, respectively. As the borderline, the second sacral nerve showed a remarkable variation. The pudendal nerve gave off the internal rectal nerve proximal to the pudendal canal and it gave off the muscular branch to the urogenital triangle in the pudendal canal. It was divided into the posterior labial nerve and the dorsal nerve of clitoris distal to the pudendal canal. Inside the pudendal canal, the internal pudendal vein, internal pudendal artery, and pudendal nerve were arranged from superomedial to inferolateral order. In other words, the pudendal nerve was the farthest from the uterus. CONCLUSION: The sorted sectioned images with labels, accompanied by the schematic drawings, could serve as references for interpreting clinical images and conducting procedures related to pudendal nerve conditions.

A Novel Perineal Nerve Block Approach for Transperineal Prostate Biopsy: An Anatomical Analysis-based Randomized Single-blind Controlled Trial.

OBJECTIVE: To develop and validate a novel perineal nerve block approach for transperineal prostate biopsy. PATIENTS AND METHODS: Five adult male cadavers were dissected to delineate the superficial and deep branches of the perineal nerve. Afterwards, 90 out of 115 patients were selected and randomly assigned to receive periprostatic, periapical triangle, or branches of perineal nerve (BPN) block. The primary outcome was the maximal pain intensity associated with transperineal prostate biopsy, which was assessed by the 10-point visual analog scale. The secondary outcomes included the number of biopsy with visual analog scale of ≥4 in each biopsy procedure, and the incidences of complications. RESULTS: On the horizontal line of the upper anal border, the locations of the superficial branch of perineal nerve on the left and right sides were 1.87 ± 0.05 cm and 1.86 ± 0.06 cm, respectively; and the deep branch were 2.15 ± 0.07 cm and 2.16 ± 0.06 cm, respectively, from the midline, and lied between the deep layer of superficial fascia and prostate capsule. The number of cases finally enrolled in data analysis in periprostatic block, periapical triangle block, and BPN block groups were 26, 27, and 30, respectively. The maximal pain intensities were 3.4 (3.1-3.7), 3.3 (3.0-3.6), and 1.8 (1.5-2.2) in the 3 groups, respectively, and the numbers of biopsy with the pain intensity of ≥4 were 4.0 (3.2-4.9), 4.2 (3.3-5.2), and 0.7 (0.1-1.2), respectively. There were 4, 3 and 4 cases developing hematuria, and 1, 1 and 2 burdened with urine retention after biopsy in the 3 groups, respectively. CONCLUSION: Collectively, BPN block is a safe, effective and repeatable local anesthesia approach for transperineal prostate biopsy.

Bilateral branching variants ofinternal and external iliac arteries

During a routine female cadaveric dissection, we found an unusual bilateral pelvic branching pattern of the internal and external iliac arteries. The vaginal and middle rectal arteries had a common origin from the right internal pudendal artery. An aberrant obturator artery arises from both external iliac arteries. A right aberrant obturator artery gives a small branch to the back of the pubic bone. The left inferior epigastric artery arises from the common trunk of the external iliac artery with the aberrant obturator artery. Knowledge of arterial variations helps to reduce the internal hemorrhage during abdominal and pelvic surgeries

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Persistent Genital Arousal Disorder: Review of Pertinent Peripheral Nerves.

INTRODUCTION: Persistent genital arousal disorder (PGAD) is a condition that is still poorly understood. Etiologies reported for PGAD are vascular, neurological, pharmacological, and psychological. Determining the neurophysiological etiology of PGAD began with developing an understanding of the underlying biomechanics of the pudendal nerve and the female sexual response. AIM: To summarize the anatomy, physiology, etiologies, diagnostics, and treatments of the pertinent peripheral nerves involved in the pathology of PGAD. METHODS: We performed a PubMed, Cochrane, Embase, Web of Science, and Google Scholar search for English-language articles in peer-reviewed journals with no predefined time period for inclusion. Terms included "humans"[All Fields] AND "persistent"[All Fields] AND/OR ("genitalia"[All Fields] OR "genital"[All Fields]) AND/OR "arousal"[All Fields] AND/OR ("disease"[All Fields] OR "disorder"[All Fields]) AND/OR "nerve"[All Fields]. The main outcomes of the papers were reviewed. MAIN OUTCOME MEASURE: The main outcome measures were the anatomy and physiology, etiologies, history and physical examination, diagnostic imaging, and current evidence for the treatment of PGAD related to the peripheral nervous system. RESULTS: Most of the literature for PGAD originates from case studies. The diagnosis of PGAD itself is still a debated topic of discussion. More recent data published indicate that this disease affects males, as well. CONCLUSION: Nerve entrapment may be a source of continuous arousal. Associated PGAD symptoms would depend on the segment of the nerve involved. Unwelcomed or unwanted arousal has been observed as the most common detrimental symptom. Pelvic 3-tesla magnetic resonance imaging is recommended in all patients with suspected nerve entrapment. Lumbosacral 3-tesla magnetic resonance imaging is recommended if a Tarlov cyst or a herniated intervertebral disc is suspected. If the peripheral nerve is the source of the pathology, surgical intervention may be curative. A multidisciplinary team approach consisting of a medical provider, pelvic floor physical therapist, and sex therapist has demonstrated benefits. There are currently no Food and Drug Administration-approved evidenced-based treatments for PGAD. Klifto KM, Dellon AL. Persistent Genital Arousal Disorder: Review of Pertinent Peripheral Nerves. Sex Med Rev 2020;8:265-273.

Ipsilateral S2 nerve root transfer to pudendal nerve for restoration of external anal and urethral sphincter function: an anatomical study.

Patients suffer bilateral sacral plexus injuries experience severe problems with incontinence. We performed a cadaveric study to explore the anatomical feasibility of transferring ipsilateral S2 nerve root combined with a sural nerve graft to pudendal nerve for restoration of external anal and urethral sphincter function. The sacral nerve roots and pudendal nerve roots on the right side were exposed in 10 cadavers. The length from S2 nerve root origin to pudendal nerve at inferior border of piriformis was measured. The sural nerve was used as nerve graft. The diameters and nerve cross-sectional areas of S2 nerve root, pudendal nerve and sural nerve were measured and calculated, so as the number of myelinated axons of three nerves on each cadaver specimen. The length from S2 nerve root to pudendal nerve was 10.69 ± 1.67 cm. The cross-sectional areas of the three nerves were 8.57 ± 3.03 mm2 for S2, 7.02 ± 2.04 mm2 for pudendal nerve and 6.33 ± 1.61 mm2 for sural nerve. The pudendal nerve contained approximately the same number of axons (5708 ± 1143) as the sural nerve (5607 ± 1305), which was a bit less than that of the S2 nerve root (6005 ± 1479). The S2 nerve root in combination with a sural nerve graft is surgically feasible to transfer to the pudendal nerve for return of external urethral and anal sphincter function, and may be suitable for clinical application in patients suffering from incontinence following sacral plexus injuries.

The ENTRAMI technique: Endoscopic transgluteal minimal invasive technique for implantation of a pudendal electrode under full visual control: A cadaver study.

AIM: The aim of this article is to describe a minimal invasive trans gluteal endoscopic approach to implant a pudendal electrode for neuromodulation under full visual control. METHODS: Eight trans gluteal approaches were performed on four cadavers. The sacral transforaminal percutaneous technique was performed to implant the electrode. The electrode was then picked up and placed under visual control next to the pudendal nerve. RESULTS: The first trocar was placed in the upper lateral quadrant of the gluteal region. The 0° optical system was used to help with the pneumodissection to identify the sciatic nerve. At that point a second 3 mm trocar was placed to insert a dissecting grasping forceps. In some cases, a second 3 mm trocar was placed. A step by step dissection, based on anatomical findings, was necessary to be able to locate the pudendal nerve. The electrode, which was placed percutaneously and transforaminal through S3 or S4, was picked up and placed under full visual control next to the pudendal nerve, slightly entering the Alcock's canal. The electrode was placed in an ideal manner, meaning that all 4-contact points of the electrode are in parallel and in contact with the targeted nerve. The electrode was fixed in that ideal position at the level of the sacrospinous ligament. After placement of that electrode, an X-ray of the pelvic area was done. CONCLUSIONS: The ENTRAMI technique allows optimal pudendal electrode placement under full visual control and should now be tested in a clinical setting.

Correlation between Anatomical Segments of the Pudendal Nerve and Clinical Findings of the Patient with Pudendal Neuralgia.

BACKGROUND: The objective was to describe clinical findings and outcomes of patients with pudendal neuralgia in relation with the anatomical segment affected. METHODS: Fifty-one consecutive patients with chronic perineal pain (CPP) located in the areas supplied by the pudendal nerve (PN), from January 2011 to June 2012, were analyzed. RESULTS: The distribution of pain at perineal, dorsal clitoris and inferior anal nerves was 92.2, 31.4 and 25.5% respectively. The duration of pain was longer when the dorsal clitoris nerve (DCN) was affected (p < 0,003). The pain in the pudendal canal was frequently associated with the radiation of pain to the inferior members (p < 0.043). CONCLUSION: CPP and radiation of pain to lower limbs suggest a disorder at the second segment of PN. A positive Tinel sign in the third segment indicates a nerve entrapment. In terminal branches, pain was more frequent at the perineal nerve and more persistent at the DCN.

Anatomy of the Pudendal Nerve and Other Neural Structures Around the Proximal Hamstring Origin in Males.

PURPOSE: To define the anatomy of the pudendal nerve in relationship to the proximal hamstring and other nearby neurological structures during proximal hamstring repair. METHODS: Six fresh-frozen human cadaveric hemi-pelvises from male patients ages 64.0 ± 4.1 years were dissected in prone position with hips in 10° flexion to identify the relationship of proximal hamstring origin to surrounding neurologic structures including the pudendal nerve, sciatic nerve, and posterior femoral cutaneous nerve. Two independent observers used digital calipers to measure distances. RESULTS: The pudendal nerve emerged at the inferior border of the piriformis muscle 6.3 ± 1.4 cm from the superior aspect of the proximal hamstring origin. It passed the superior border of the sacrotuberous ligament 3.0 ± 0.6 cm from the superior aspect and 3.9 ± 0.7 cm from the medial aspect of the hamstring origin. It crossed the inferior border of the sacrotuberous ligament 3.0 ± 0.4 cm from the superior aspect and 2.7 ± 0.7 cm from the medial aspect of the proximal hamstring origin. The shortest distance from the hamstring origin to the pudendal nerve was 2.6 ± 0.5 cm from the superior aspect and 2.3 ± 0.8 cm from the medial aspect. The shortest distance from the hamstring origin to the pudendal nerve was located deep to the sacrotuberous ligament in all cadavers. The sciatic nerve was an average of 1.1 ± 0.1 cm lateral to the lateral aspect of the proximal hamstring origin. The posterior femoral cutaneous nerve was located between the hamstring origin and the sciatic nerve, 0.7 ± 0.2 cm lateral to the lateral aspect of the proximal hamstring origin. CONCLUSIONS: The proximal hamstring origin lies in close proximity to surrounding nerves, including the pudendal, sciatic, and posterior femoral cutaneous nerves. CLINICAL RELEVANCE: Knowledge that the pudendal nerve lies 2 to 3 cm superior and medial to the proximal hamstring origin may help to prevent iatrogenic damage during surgical dissection and retraction when performing proximal hamstring repair or deep gluteal space endoscopy.

The anatomy of forearm free flap phalloplasty for transgender surgery.

Transgender surgeries are becoming more frequent and visual interpretation of anatomy is essential for both surgeons and patients. Since the forearm free flap phalloplasty was introduced in 1984, it has been known to provide reliable cosmetic and functional results for transitioning men compared with phalloplasty by different flaps. Surgical text descriptions were enhanced by the creation of new anatomic illustrations. The forearm free flap consists of the anterior forearm skin, subcutaneous tissue, fascia containing the radial artery as the perforator and its venae comitantes, cephalic and basilic veins, and lateral and medial antebrachial cutaneous nerves are demonstrated in relation to the surgically derived flap. Song's forearm free flap phalloplasty requires two surgical stages with a three-month interval between the stages: prelamination of a neourethra and construction of a neophallus. The neophallus created by forearm flap phalloplasty is reported to achieve acceptable aesthetical and psychological satisfaction, appropriate size and shape, and satisfying sexual intercourse. Despite increasing experiences in gender confirming surgery with modifications made by many authors, urethral complications including fistula and/or stricture formation are the leading causes of reoperation. The poor esthetic outcome of the forearm donor site and a decrease in rigidity of the neophallus are the main limitations. Illustrations of anatomy help inform surgical choice and understanding of risks and benefits by patients. The anatomy of the free forearm flap phalloplasty supports creation of a neophallus for transsexual anatomy revision. Clin. Anat. 31:145-151, 2018. © 2017 Wiley Periodicals, Inc.

The anatomy of abdominal flap phalloplasty for transgender surgery.

Abdominal flap phalloplasty is surgical construction of a neophallus using a pedicled abdominal flap for patients transitioning female to male, for males whose penis is congenitally absent, or lost from trauma. It is an option for trans men whose goals do not require urethroplasty or vaginectomy but would like a phallus suitable for male gender appearance. A prosthesis can be placed for penetrative sexual capability. Surgical text descriptions were enhanced by creation of new anatomic illustrations. Anatomy of donor site and surgical technique leading to creation of the neophallus are demonstrated in detail with new relevant illustrations. Significant structures of the donor site of the abdominal flap include the superficial external pudendal artery and ilioinguinal nerve that provide the blood supply and sensory innervation to the base of the flap, respectively. As a pedicled phalloplasty procedure, microsurgical anastomosis is not needed. Patients can expect to have tactile sensation but not innate rigidity. The dorsal nerve of clitoris (and sometimes the clitoris itself) is preserved to provide erogenous sensation. Abdominal flap phalloplasty makes it possible to maintain the natural blood supply and innervation to the neophallus. The neophallus created by abdominal flap phalloplasty has the advantage of homogeneous skin color and texture from contiguous skin. Grafting leaves a less stigmatizing horizontal scar running from one side of the pelvis to the other along the lower abdomen. The anatomy of the abdominal flap phalloplasty supports creation of a neophallus for transsexual anatomy revision. Clin. Anat. 31:181-186, 2018. © 2017 Wiley Periodicals, Inc.

A new endoscopic minimal invasive approach for pudendal nerve and inferior cluneal nerve neurolysis: An anatomical study.

AIM: To describe a new minimal invasive approach of the gluteal region which will permit to perform neurolysis of the pudendal and cluneal nerves in case of perineal neuralgia due to an entrapment of these nerve trunks. METHOD: Ten transgluteal approaches were performed on five cadavers. Relevant anatomic structures were dissected and further described. Neurolysis of the pudendal nerve or cluneal nerves were performed. Landmarks for secure intraoperative navigation were indicated. RESULTS: The first operative trocar for the camera was inserted with regards to the iliac crest in the deep gluteal space. With the aid of pneumodissection, the infragluteal plane was dissected. The piriformis muscle was identified as well as the sciatic and the posterior femoral cutaneous nerve. Consequently, the sciatic tuberosity was visualized together with the cluneal nerves. Hereafter, the second trocar was introduced caudal to the first one and placed on an horizontal line passing at the level of the coccyx, allowing access to the ischial spine and the visualization of the pudendal nerve and vessels. A third 5 mm trocar was then inserted medial from the first one, permitting to dissect and transsect the sacrospinous ligament. The pudendal nerve was subsequently transposed and followed on its course in the pudendal channel. CONCLUSIONS: A reliable exploration of the gluteal region including identification of the sciatic, pudendal, and posterior femoral cutaneous nerves is feasible using a minimal invasive transgluteal procedure. Consequently, the transposition of the pudendal nerve and the liberation of the cluneal nerves can be performed.

[Magnetic resonance neurography for the identification of pudendal neuralgia]. / Neurografía por resonancia magnética para la identificación de la neuralgia del nervio pudendo.

The pudendal nerve entrapment is an entity understudied by diagnosis imaging. Various causes are recognized in relation to difficult labors, rectal, perineal, urological and gynecological surgery, pelvic trauma fracture, bones tumors and compression by tumors or pelvic pseudotumors. Pudendal neuropathy should be clinically suspected, and confirmed by different methods such as electrofisiological testing: evoked potentials, terminal motor latency test and electromyogram, neuronal block and magnetic resonance imaging. The radiologist should be acquainted with the complex anatomy of the pelvic floor, particularly on the path of pudendal nerve studied by magnetic resonance imaging. High resolution magnetic resonance neurography should be used as a complementary diagnostic study along with clinical and electrophysiological examinations in patients with suspected pudendal nerve neuralgia.