Innervation of the scrotum by the anterior division of the obturator nerve - a rare variation.

The scrotum is supplied by ilioinguinal, genital branch of genitofemoral, perineal branch of the posterior cutaneous nerve of the thigh and the posterior scrotal branches of the pudendal nerve. We report an extremely rare innervation of the anterior part of the scrotum by the anterior division of the right obturator nerve. The genital branch of genitofemoral nerve did not reach the scrotum. The ilioinguinal nerve did not supply the scrotum. The anterior division of the obturator nerve gave a branch which ascended superomedially in the thigh, crossed superficial to the spermatic cord and communicated with the right ilioinguinal nerve. As it crossed the spermatic cord, it gave a scrotal branch which descended over the spermatic cord and ramified to supply the anterior part of the scrotum. Knowledge of this variation could be important to anaesthesiologists, urologists and surgeons in general.

Effect of low-threshold versus high-threshold genitalia stimuli on the cystometry parameters in male rats.

The cross talk between external genitalia and urinary bladder could be used as part of management to certain pathological conditions affecting urinary bladder. Since urinary bladder function is also affected by pathologies of other organs (e.g., colon and esophagus), the effect of genitalia stimuli on parameters of bladder function in normal or under different pathological conditions needs to be characterized. Cystometry recordings in male rats were used to examine the effect of low-threshold (LT) and high-threshold (HT) stimulation of the scrotum and penis on urinary bladder function. These effects were studied in intact, colon irritation (CI), and esophagus irritation (EI) groups. Although HT penile stimulation had a significant inhibitory effect on micturition reflex in all groups, CI hypersensitized the penile-bladder inhibitory reflex. In addition, LT penile stimulation had a significant inhibitory effect on micturition, which was significant in CI group only. On the other hand, HT penile stimulation in CI group significantly increased the timing parameters of cystometry. Whereas LT and HT penile stimuli in EI group had a significantly increasing effect on all pressure parameters of cystometry. The scrotal stimuli had minimal effect on bladder function in all groups except for HT scrotal stimulation in the CI group, where it had a significant inhibitory effect on micturition reflex and significantly increased the maximum pressure and pressure amplitude of micturition cycles. These results show that CI and EI exacerbate the effects of genitalia stimuli, especially penile stimuli, on urinary bladder function.

Spermatic Cord Block Series as a Minimally Invasive Therapy for Chronic Scrotal Content Pain.

PURPOSE: The primary aim of our study was to evaluate relief of chronic scrotal content pain after a series of spermatic cord blocks with a combination of local anesthetic and a steroid. Secondary aims were to assess factors associated with a positive response and complications. MATERIALS AND METHODS: We performed a retrospective chart review of patients who underwent spermatic cord block series for chronic scrotal content pain at our practice between 2012 and 2019. Pain scores were compared before and after treatment using an 11-point numerical pain rating scale. We performed univariate analysis to assess differences between responders and nonresponders, and the relationship between symptom duration and response was analyzed by rank-order correlation. RESULTS: We included 44 men with chronic scrotal content pain present for a median duration of 24 months who underwent a spermatic cord block series. At a median followup of 16 months, 31 patients (70.5%) experienced sustained relief, including 9 patients (20.5%) with complete resolution of pain. There were no differences between responders and nonresponders in terms of symptom duration, perceived etiology, or previous treatments, and there was no association between response and duration of pain. Minor complications occurred in 5 cases (11.4%). CONCLUSIONS: Spermatic cord block series is a safe, minimally invasive treatment for men with refractory chronic scrotal content pain. Response to cord block series appears to be independent of symptom duration, perceived etiology or prior medical and surgical treatments. Future studies should be conducted to evaluate long-term durability and predictors of success.

Activity of the external urethral sphincter evoked by genital stimulation in male rats.

AIMS: To determine whether the external urethral sphincter (EUS) fasciculi of male rats respond to the mechanical stimulation of genital structures and to characterize the pattern of the electromyographic (EMG) activity of the three regions of the EUS: the cranial (CrEUS), the medial (MeEUS) and the caudal (CaEUS). METHODS: Electromyographic signals were recorded from the CrEUS, MeEUS and CaEUS regions of the male rat's EUS, before, during and after the mechanical stimulation of the urogenital structures. RESULTS: The CrEUS, MeEUS and CaEUS regions responded when brushing and squeezing the foreskin and glans as well as to penile and prostatic urethral distension. The CaEUS EMG amplitude (P < 0.01) and frequency (P < 0.05) were lower in comparison to the CrEUS and MeEUS responses to the mechanical stimulation. In addition, the CaEUS was characterized by a short or no afterdischarge. In contrast, the CrEUS and MeEUS responded by presenting a long discharge after the penile or prostatic urethral distension. CONCLUSIONS: The activity of the EUS is modulated by both, cutaneous and visceral genitourinary stimuli, with motor units being activated by mechanoreceptors located in the foreskin, glans, bladder, and urethra. The CrEUS, MeEUS and CaEUS have differential EMG patterns, indicating that the EUS consists of three anatomically and functionally different regions. Precise coordination in the muscular activity of these regions may be crucial for the control of male expulsive urethral functions, i.e., during voiding and ejaculation. Neurourol. Urodynam. 35:914-919, 2016. © 2015 Wiley Periodicals, Inc.

Novel presentation of a cricket ball-related intra-abdominal injury: genitofemoral nerve referred pain.

Serious intra-abdominal injuries are very uncommon in cricket; traumatic cricket injuries are traditionally musculoskeletal, soft tissue or maxillofacial in origin. The cause of such cricket injuries can be broadly divided into collision type injuries (a result of direct contact with the ball or bat, another player, the ground or boundary) or overuse injuries (due to running, throwing, batting, bowling, repetitive movements and overexertion). This case report describes a rare cause of small bowel perforation and suspected genitofemoral nerve injury secondary to the direct impact of a cricket ball, and includes a brief review of blunt abdominal injuries resulting in isolated small bowel perforations.

Microsurgical Spermatic Cord Denervation as a Treatment for Chronic Scrotal Content Pain: A Multicenter Open Label Trial.

PURPOSE: We prospectively evaluated the results of microsurgical spermatic cord denervation in a series of patients with chronic scrotal content pain in a multicenter study, including 1 center in Germany and 3 centers in Chile. MATERIALS AND METHODS: A total of 50 patients with chronic scrotal content pain more than 3 months in duration were prospectively selected for standardized operative microsurgical spermatic cord denervation as pain treatment. In all patients preoperative management included a positive response to a spermatic cord block test with local anesthesia. Pain severity was assessed using an analog visual pain scale (range 0 to 10) for 30 consecutive days. A total of 52 testicular units were operated on using a subinguinal approach. In all cases a surgical microscope was used to identify the arteria testicularis. RESULTS: No intraoperative complications were observed and no testicular units were lost. Two reoperations were performed, including 1 for hematocele and 1 for hydrocele. Six months after surgery 40 patients (80%) were completely pain-free. In 6 patients (12%) intermittent testicular discomfort persisted, which could be managed by acetaminophen on demand. Four patients (8%) had no change in pain severity after surgery. CONCLUSIONS: After proper selection of patients microsurgical spermatic cord denervation seems to be a safe and efficient procedure to treat chronic scrotal content pain. Considering the limitations of the study, a randomized, controlled trial with longer followup is highly warranted.

Scrotal and perineal sensory neuropathy after urethroplasty for bulbar urethral stricture disease: an evaluation of the incidence, timing, and resolution.

OBJECTIVE: To examine the timing, incidence, and resolution of scrotal and perineal sensory neuropathy after urethroplasty for bulbar urethral stricture disease. MATERIALS AND METHODS: We performed an institutional review board--approved retrospective review of our urethroplasty database with specific attention paid to patient demographics, stricture location, repair type, and postoperative sensory neuropathy defined as the complaint of hypesthesia, anesthesia, paresthesia, hyperesthesia, and pain in the scrotal and perineal region after surgery. Incidence and reported times to onset and resolution of sensory neuropathy were compared among our cohort. RESULTS: A total of 155 men underwent urethroplasty for bulbar urethral stricture disease from January 2007 to December 2012. One hundred forty-three of 155 men (92%) had postoperative data available for analysis. The average age at surgery was 47 ± 15 years and average stricture length was 2.1 ± 1.4 cm. Repair types were excision and primary anastomosis (101 of 143; 71%), augmented anastomotic repair (31 of 143; 22%), onlay repair (4 of 143; 3%), and perineal urethrostomy (7/143, 5%). Twenty of 143 men (14%) experienced postoperative scrotal and perineal neuralgia at a median time of 108 days (range, 18-160 days) from surgery. Fourteen of 20 men (70%) had subsequent follow-up visits, and all of these men had resolution of the pain, without treatment, at a median reported time of 271 days from surgery. There were no significant differences in incidence, resolution, or timing of sensory neuropathy among repair types. CONCLUSION: Our findings indicate that approximately 14% of men who undergo urethroplasty for bulbar urethral stricture disease experience postoperative scrotal and perineal sensory neuropathy. This appears to be transient with 100% resolution in our patients with available follow-up.

The surgical anatomy of the perineum.

The anatomy of the perineum and pelvis is complex. Those outside the specialist fields of colorectal surgery, urology and gynaecological surgery often have a less-than-complete understanding of the anatomical details of this region. The recent increase in complicated pelvic and perineal injuries caused by the detonation of Improvised Explosive Devices has brought into sharp focus, the importance of this area of surgical anatomy. The following article describes, in a systematic and detailed manner, the anatomy of the urogenital and anal regions of the perineum. The terminology in relation to the fascial layers and structures encountered in the perineum is elucidated. In addition, the surgical anatomy of the scrotum and its contents and the ligamentous support of the penis are described, with clear illustrations throughout. It is intended that this article will go some way towards clarifying the anatomy underlying the surgical management of complex perineal/pelvic injuries, and benefit both the specialist and non-specialist military surgeon.

Cystic schwannoma of the pelvis.

Schwannomas are benign tumours that arise from the Schwann cells of nerve fibres. They commonly occur in the head and neck, mediastinum and extremities. They are extremely rare in the pelvis. These are usually slow-growing tumours and are often detected incidentally. Preoperative diagnosis is extremely difficult as there are no definitive signs on imaging. Aspiration biopsy is often inconclusive or misleading. Surgical excision is both diagnostic and therapeutic. As these tumours are often large in size, open excision is most commonly performed. We describe a case of a large, cystic schwannoma of the pelvis causing bladder outlet obstruction and bilateral hydroureteronephrosis. Complete surgical excision was performed laparoscopically.

A gentle mechanical skin stimulation technique for inhibition of micturition contractions of the urinary bladder.

Effects of gentle skin stimulation of various segmental areas on the micturition contractions of the urinary bladder were examined in anesthetized male rats. The bladder was expanded by infusing saline via urethral cannula until the bladder produced rhythmic micturition contractions as a consequence of rhythmic burst discharges of vesical pelvic efferent nerves. Gentle stimulation was applied for 1 min by slowly rolling on top of skin with an elastomer "roller". Rolling on the perineal area inhibited both micturition contractions and pelvic efferent discharges during and after stimulation. Stimulation of the hindlimb, abdomen and forelimb inhibited micturition contractions after stimulation ended, in this order of effectiveness. During stimulation of the perineal skin, the reflex increase in pelvic efferent discharges in response to bladder distension to a constant pressure was also inhibited up to 45% of its control response. The inhibition of the micturition contractions induced by perineal stimulation was abolished, to a large extent by the opioid receptor antagonist naloxone and completely by severing cutaneous nerves innervating the perineal skin. We recorded unitary afferent activity from cutaneous branches of the pudendal nerve and found that the fibers excited by stimulation were low-threshold mechanoreceptive Aß, Aδ and C fibers. Discharge rates of afferent C fibers (7.9 Hz) were significantly higher than those of Aß (2.2 Hz) and Aδ (2.9 Hz) afferents. The results suggest that low frequency excitation of low threshold cutaneous mechanoreceptive myelinated and unmyelinated fibers inhibits a vesico-pelvic parasympathetic reflex, mainly via release of opioids, leading to inhibition of micturition contraction.

Identification of perineal sensory neurons activated by innocuous heat.

C-fiber sensory neurons comprise nociceptors and smaller populations of cells detecting innocuous thermal and light tactile stimuli. Markers identify subpopulations of these cells, aiding our understanding of their physiological roles. The transient receptor potential vanilloid 1 (TRPV1) cation channel is characteristic of polymodal C-fiber nociceptors and is sensitive to noxious heat, irritant vanilloids, and protons. By using immunohistochemistry, in situ hybridization, and retrograde tracing, we anatomically characterize a small subpopulation of C-fiber cells that express high levels of TRPV1 (HE TRPV1 cells). These cells do not express molecular markers normally associated with C-fiber nociceptors. Furthermore, they express a unique complement of neurotrophic factor receptors, namely, the trkC receptor for neurotrophin 3, as well as receptors for neurturin and glial cell line-derived neurotrophic factor. HE TRPV1 cells are distributed in sensory ganglia throughout the neuraxis, with higher numbers noted in the sixth lumbar ganglion. In this ganglion and others of the lumbar and sacral regions, 75% or more of such HE TRPV1 cells express estrogen receptor alpha, suggestive of their regulation by estrogen and a role in afferent sensation related to reproduction. Afferents from these cells provide innervation to the hairy skin of the perineal region and can be activated by thermal stimuli from 38 degrees C, with a maximal response at 42 degrees C, as indicated by induction of extracellular signal-regulated kinase phosphorylation. We hypothesize that apart from participating in normal thermal sensation relevant to thermoregulation and reproductive functions, HE TRPV1 cells may mediate burning pain in chronic pain syndromes with perineal localization.

Evaluation of genitofemoral nerve motor conduction in inguinoscrotal pathologies.

AIM: Inguinoscrotal pathologies are commonly seen in childhood. The genitofemoral nerve (GFN) is responsible for sensitive innervations of scrotal region and the motor innervations of cremasteric muscle. GFN also innervates the afferent and efferent pathways of cremasteric reflex. A prospective study was performed to evaluate the possible relation between inguinoscrotal pathologies and GFN motor functions. METHODS: Patients with inguinal hernia, hydrocele, undescended or retractile testicles, aged between 2-12 years were enrolled in the study. Bilateral latency and duration of GFN motor conductions (GFNMC) were obtained electrophysiologically by surface electrodes. GFNMC recordings of non-pathological sides were assessed as control group. Latency and duration of each group were compared with control group (Mann-Whitney U test). P values lower than .05 were considered significant. RESULTS: Seventy-three electrophysiologic evaluations were investigated in inguinal hernia (n:18), hydrocele (n:9), undescended testicle (n:14), retractile testicle (n:12) and control (n:20) groups. There was no age difference between groups and controls. Latency was significantly prolonged in inguinal hernia group when compared with control group (P = .028). Although the latencies were shortened in undescended testicle group, no significant difference detected (P > .05). CONCLUSION: Prolonged latencies in inguinal hernia may be a result of nerve trap caused by hernia sac. GFN motor functions showed no causative role in other inguinoscrotal pathologies. It can be also suggested that clinical features of other inguinoscrotal pathologies were not affected by GFN motor functions. Electrophysiological studies in younger age groups with large number of patients are needed to support our suggestions.

[Perineoscrotal pain after InVance suburethral sling: Cadavre anatomical study]. / Les douleurs périnéo-scrotales après soutènement urétral prothétique type InVance : étude anatomique sur cadavres.

OBJECTIVE: The authors investigated the anatomical basis for prolonged perineoscrotal pain after InVance bone-anchored male sling for the treatment of urinary incontinence after prostatic surgery in order to propose technical advice to reduce the frequency of this complication. MATERIAL AND METHOD: The authors dissected three formalin-preserved male cadavres and reviewed the literature on perineal anatomy and complications of the surgical technique. RESULTS: Cadavre dissections demonstrated the origin, course and termination of the perineal nerve, a branch of the pudendal nerve derived from the S2-S3-S4 sacral nerve roots. Its superficial branch, accompanied by its blood supply, ensures sensory innervation of the anterior part of the perineum and posterior surface of the scrotum. This branch is situated in the zone of lateral dissection towards ischiopubic rami. Potential lesions of this nerve could be due to coagulation of the vascular pedicle, stretching during lateral dissection towards ischiopubic rami, or damage to its anastomoses with the scrotal branch of the lateral cutaneous nerve of the thigh during exposure of the sites of implantation of ischiopubic screws. CONCLUSION: Trauma to the superficial perineal nerve is probably responsible for perineoscrotal pain after InVance perineal surgery. This operative trauma must therefore be reduced by identifying the bulbourethral muscle before dissecting laterally and by limiting the use of coagulation.

[Applied microanatomic study of pudendal-thigh skin flap].

OBJECTIVE: To investigate the microanatomic basis of the pudendal-thigh flap and provide the anatomic basis for clinical application. METHODS: Skin microdissection of the pudendal regions was performed on 11 adult cadavers (22 sides). Then, the clinical way was simulated to obtain the flaps, and the vessels and nerves contained in them were surveyed. After that, the tissues in the deep part were dissected, and the vessels and nerves were traced back to their origins. The notes were taken. RESULTS: The blood supply to the pudenal regions was plentiful and constant. The initiation point of the superficial external pudendal artery was 2.14+ 0.23 mm in diameter; one branch of it was the inguinal branch and the other branch was the perineal branch. Their diameters were 1.38+0.34 mm and 1.21+0.24 mm. The initiation point of the posterior labial or scrotum arteries was 1.13+ 0.24 mm in diameter, and the lateral branch was 0. 67+0. 33 mm in diameter. The anterior cutaneous branch of the obturator artery was 1.68+ 0.11 mm in diameter. The position of all the blood vessels was relatively constant, especially the external pudendal artery and the lateral branch of the posterior scrotal artery. Many of the blood vessels passed through the areas of the pudendum and the thigh, anastomosed with each other. Three groups of the vascular net passed through the upper, middle and lower parts of the flap. Three main groups of the innervation were as the following: the ramus femoralis nervi genitofemoralis, the cutaneous branches of the ilioinguinal nerve, and the post-nerve of the scrotum or the labia vulvae. CONCLUSION: The pudendal-thigh flap has an abundant blood supply, and its dissection is convenient with an easy incision; the donor site is covert. The pudendal-thigh skin flap has the following advantages for the sexual organ reconstruction: the skin flap can have a good sensation and a good shape, and the operative procedure is easy to perform.

Acute scrotal pain from idiopathic ilioinguinal neuropathy: diagnosis and treatment with EMG-guided nerve block.

Ilioinguinal nerve entrapment presents with a clinical triad of pain in the iliac fossa and inguinal region, sensory abnormalities in the cutaneous distribution of the nerve and tenderness on palpation 2-3 cm medial and below the anterior superior iliac spine. The syndrome poses diagnostic difficulties, as genitofemoral nerve entrapment and non-neurological conditions of the lower abdomen may cause similar pain. We report on a patient with acute groin pain radiating towards the scrotum, caused by ilioinguinal nerve entrapment. The clinical diagnosis was strongly suggested by electromyographic examination, using the monopolar needle as a deep stimulating electrode. Subsequent nerve blockade caused complete relief of symptoms. The technique is described. Future applications for treatment of post-surgical pain are discussed.

Characteristics of ejaculated rat semen after lesion of scrotal nerves.

The scrotum, representing the pouch surrounding the testes and their associated structures, plays a significant role in maintaining the gonad at a temperature lower than that of the body. Although thermoregulation of the testes has been ascribed as a main function of the scrotum, here we found that mechanical stimulation of the scrotum is important during mating to facilitate the appropriate expulsion of semen during ejaculation. Previously we showed that the scrotal skin area is innervated by two nerve branches, the proximal (Psb) and distal (Dsb) scrotal branches which supply the proximal or distal half of the scrotum, respectively. The sensory field of each nerve is testosterone-dependent. The decreased androgen levels following castration reduce the sensitive area to mechanical stimuli that can be restored following exogenous administration of the hormone. Here, we tested the effect of scrotal nerve transection on sexual parameters of experienced male rats. Data show that lesion of PSb or DSb alone or combined did not affect the execution of sexual behavior. However, these lesions significantly reduced the proportion of males that expelled semen during ejaculation, with that semen showing a reduced quantity of sperm. Thus, scrotal nerves are important in reproduction not for the appropriate display of sexual behavior, but for the expulsion of a normal quantity of semen and number of sperm during ejaculation. Our suggestion is that scrotal afferents trigger spinal reflexes to activate autonomic efferents supplying the male reproductive tract for the control of seminal emission.

Anatomical bases of prolonged ilio-inguinal-hypogastric regional anesthesia.

Although anesthesia and post-operative analgesia are associated with specific morbidity, regional anesthesia is not systematically given during groin hernia surgery. The goals of this work were to determine the anatomical bases of safe ilio-inguinal (II)-hypogastric anesthesia that can be prolonged into the post-operative period and to validate this technique on anatomical preparations and in clinical situations. We studied the courses of the ilio-hypogastric (IH) and II nerves in 33 halves of 20 embalmed adult cadavers. The intermediate portion of the IH and II nerves, located between the transverse and the internal oblique muscles, were found to be suitable for a simultaneous block with a single injection. We assessed the feasibility of injecting a percutaneous infiltration into this space by injecting a dye before dissection. In 75% of cases, we observed percutaneous coloring of the nerves, confirming that this site was suitable. To guide the infiltration, the points where the nerves passed through the transverse and the internal oblique muscles were located from the iliac crest and anterior and superior iliac spine, respectively. The nerve trunks were grouped for over 5 cm in a cell-fat layer running between these two deep muscles. It was possible to position a micro-catheter in this anatomical space to allow repeated injections. The results of this anatomical study were used to modify the technique so that it could be used to provide regional anesthesia in five patients operated on for hernia. Post-operative pain was very effectively controlled in four cases with no complications.