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Surgical lumbar sympathectomy was commonly performed on patients with painful obliterative arterial disease. Percutaneous chemical sympathectomy is an alternative to surgery and was described by Mandl in 1926. His approach depended upon the needle contacting the transverse process to gauge depth before being inserted more deeply. Variations of this technique were subsequently described, but it was the introduction of radiographic techniques that allowed identification of landmarks and precise positioning of the needle.

The purpose of this study was to evaluate microcirculatory dynamics following muscle flap denervation. A modification of standard cremaster muscle flap was used. Fifty male Sprague-Dawley rats were studied in two experimental groups of 25 rats each, as follows: Group I (control), after flap isolation, the neurovascular pedicle was left intact; group II (denervation), following muscle isolation at 1 cm segment of genitofemoral nerve was excised and denervated muscle was preserved in the medial border of rat hind limb. For chronic evaluation the cremaster was withdrawn from the leg and prepared for in vivo observations after days 1, 3, 7, and 14. The following measurements were taken: vessel diameters, red blood cell velocities, and number of perfused capillaries. In group II a 15% increase in arteriolar diameter was observed. Throughout the entire 14 day period denervated flaps presented 27% more perfused capillaries. Flap denervation proved to increase capillary perfusion significantly (P < 0.05). The cremaster muscle tube-flap model introduced in this study allows for chronic observation of the microcirculation.

The adipose tissue is unique in its ability to expand and regress throughout life. In developed and developing countries, the overall adipose tissue expansion phase outpaces regression, resulting in an ever-expanding obese society. To shed the “extra pound”, a significant number of patients undergo surgeries to remove the unwanted fat. The resulting “medical wastes” are however potential therapeutic treasures for two reasons. One is that the adipose tissue is a rich source of multipotent mesenchymal cells called adipose-derived stem cells (ADSCs) 1,2; and the other is that the adipose extracellular matrix (ECM) can be fabricated into acellular scaffolds for tissue engineering 3–5. In regard to ADSCs, these cells have been shown to differentiate into Schwann cells that formed myelin sheath on axons 6 and have been used to seed nerve conduits for peripheral nerve repair 7–9. In addition, we have shown that ADSCs secrete neurotrophic factors that promote cavernous nerve (CN) regeneration 10,11. In regard to adipose ECM, the fabricated scaffolds have been shown to support adipogenic differentiation of ADSCs 5. In the present study we combined ADSC’s neuroregenerative potential and adipose ECM’s scaffold potential to construct nerve grafts for the repair of peripheral nerves, in this case, CN. The CN innervate penile erectile tissue and are essential for erection. Due to their proximity to the prostate, bladder, and rectum, these nerves are often damaged during surgeries on these organs, resulting in erectile dysfunction (ED) 12–14. In particular, prostate cancer is the most prevalent malignancy in men and is often treated by radical prostatectomy, causing damage to the CN and subsequent ED 15. To repair the damaged CN, autologous nerve grafting with sural nerves has initially been shown to result in an erectile function recovery rate of 43% 16. However, the harvest of the sural nerves causes donor site morbidity and requires the collaborative support of plastic surgeons. On the other hand, the harvest of the genitofemoral nerves causes minimal morbidity and can be done by the urological surgeon. CN repair with genitofemoral nerve grafting has an erectile function recovery rate of approximately 50% 17,18. On an experimental basis, grafting with decellularized CN from donor rats has also been attempted 19. However, the clinical applicability of such a treatment procedure is rather low because of the need to harvest the CN from human volunteers or cadavers. In the present study we processed lipectomized human and rat adipose tissues into acellular matrices, seeded the rat matrix with allogenic rat ADSCs, and grafted the seeded matrix into rats with transected CN. We observed variable but substantial recovery of erectile function following such grafting.

Administration of 10 micrograms of capsaicin into the anterior portion of a lumbar intervertebral disc of rats pretreated with Evans blue (i.v.) caused dye extravasation in the groin skin. This phenomenon occurred even when the spinal nerve of the same segment, bilateral sympathetic trunks, and/or the anterior L2 spinal root had been cut; it did not occur in rats with a cut genitofemoral nerve. Infiltration of capsaicin solution directly into the genitofemoral nerve did not cause dye extravasation. These results suggested the presence of dichotomizing sensory C-fibers which innervate both the intervertebral discs and the groin skin in the L2 spinal nerve. If such dichotomizing fibers exist in man, they may contribute to the groin pain sometimes associated with intervertebral disc lesions.

Erectile dysfunction is a significant complication of radical pelvic surgery in men. Using the rat as an experimental model, we investigated the feasibility of repairing surgically ablated cavernosal nerves. Known fertile male Sprague-Dawley rats were randomly divided into three surgical groups of 30 animals (60 study nerves) per group consisting of nerve ablation, immediate nerve reconstruction, and control groups. The nerve ablation group had 5-mm sections of the cavernosal nerve excised bilaterally. The nerve graft group had 5-mm sections of the cavernosal nerve excised bilaterally, followed by immediate microsurgical reconstruction with an autologous interposition nerve graft utilizing the ipsilateral genitofemoral nerve bilaterally. The anastomoses were performed with 10-O nylon sutures at 16 to 25x magnification. The control group underwent sham operations with the cavernosal nerves being exposed only. Erectile function was evaluated at 1, 2, 4, and 6 months postoperatively. Return of erectile function was defined as tumescence of the corporal bodies with application of direct electrical stimulation (3 V of 5 msec pulses at 20 Hertz) to the proximal cavernosal nerves. The 4- and 6-month electrical stimulation studies resulted in tumescence from 65 and 75% of the grafted nerves, which represented a significant difference compared to the ablated group 11 and 5%, respectively (P less than 0.001 at 4 and 6 months). Behavioral copulatory studies, performed prior to electrical stimulation testing, corresponded closely with the results of electrically induced tumescence. We conclude that in this experimental model immediate nerve graft repair appears to be a successful method of salvaging erectile function when the cavernosal nerves have been divided.

The genitofemoral nerve is a key factor in the inguinoscrotal descent of the testis. The effect of androgens may be mediated via the central nervous system, which in turn secretes the neurotransmitter calcitonin gene-related peptide (CGRP) at the genitofemoral nerve endings, to cause testicular descent. The effect of endogenous CGRP was examined by weekly injections of a vehicle with or without synthetic antagonist (CGRP 8–37) into the developing scrotum of neonatal mice. The descent of the testis was delayed in the experimental group compared with the control group. At 2 weeks of age 43% of controls had descended testes compared with 0% of experimental animals. At 3 weeks of age 17% of experimentals still had undescended testes, whereas all testes were descended in controls. At 4 weeks 3 testes remained undescended in the experimental group. It is concluded that the CGRP antagonist can retard testicular descent. This result is consistent with the hypothesis that CGRP is an important intermediary in testicular descent.

A retrospective study was conducted to determine the incidence of cryptorchidism in male patients with arthrogryposis. During a 49-year period 107 patients were identified, 60 of which were boys, and 23 had undescended testes. We were able to seperate 52 of the male patients into four broad etiologic categories. The largest group contained patients with arthrogryposis due to neurologic disorders, including 27 boys with amyoplasia, a primary disorder of anterior horn cells, and 12 boys with other neurologic conditions. Fourteen of the patients with neurologic disorders had cryptorchidism, and in 9, it was associated with amyoplasia. Twelve boys had a variety of conditions due to joint and contiguous tissue abnormalities, and undescended testes were found in 6 patients in this category. Joint contractures secondary to muscle disease or fetal constraint were recognized in only 1 patient who did not have cryptorchidism. In 8 patients the origin of the arthrogryposis could not be determined from review of the records, and 3 boys in this group had cryptorchidism. In the fetus with arthrogryposis involving the hips and lower extremities, external indirect compression of the inguinoscrotal region in the third trimester by associated limb deformities has been considered the most likely basis for cryptorchidism. Alternatively, the genitofemoral nerve, which originates from the upper lumbar spinal cord, is important in inguinoscrotal testicular descent. Therefore, a neurogenic disorder such as amyoplasia might lead to cryptorchidism directly by degeneration of the nucleus of the genitofemoral nerve, and therefore play a major role in the development of undescended testes in this patient population.

Neuropathy involving the genitofemoral nerve occurs infrequently, but must be distinguished from entrapment of the ilioinguinal nerve. The nerve eventually divides into the external spermatic (genital) and the lumbo-inguinal (femoral) nerves. The genital branch passes through the internal inguinal ring where it is subject to entrapment. The syndrome is characterized by chronic pain and paresthesia in the distribution of the nerve.

Introduction: Postradical prostatectomy erectile dysfunction is thought to be neurogenic in origin, and some attempts to improve potency have focussed on regenerating the cavernous nerves. Testosterone has profound positive effects on nerve regeneration. The present study aims to evaluate whether testosterone has any effect on the regeneration of cavernous nerves. Materials and Methods: Forty-five male Sprague–Dawley rats underwent bilateral cavernous nerve neurotomy followed by unilateral nerve graft using genitofemoral nerve. Animals were then randomised to castrate, intact and testosterone treated arms. At 3 months electrostimulation was performed measuring intracavernosal pressure responses. Grafted nerve segments were then harvested for histological analysis. Results: Significant difference in maximal intracavernosal pressure (MICP) response between groups – mean MICPs were 24, 47 and 59 for castrate, intact and testosterone treated groups respectively (P = 0.003, anova). Total axon counts within grafted segments did not differ significantly between treatment groups, but concentration of nNOS-containing axons was significantly decreased in castrate animals. Conclusions: Castration resulted in a significant reduction in erectile response to electrostimulation following interpositional nerve grafting. These effects appear to be due to changes in axonal regeneration in differing androgen environments, especially in the regeneration of nNOS containing axons. Clinically, this implies that nerve grafts will be of little functional use in the face of androgen ablation.

Dear Editor: In the article ‘‘Long-term follow-up after Lichtenstein hernioplasty in a general surgical unit’’ Verstraete and Swannet noted a fairly high level of chronic and occasional discomfort in patients following Lichtenstein hernia repairs. They suggested that further studies to prevent or cure chronic pain and occasional discomfort following a Lichtenstein hernioplasty are necessary, since the frequency of these complications is higher than the prevalence of recurrence. They went on to propose a theory that the origin of the chronic pain in their patients could be attributed to central neuroplasticity. They also stated that the dysjaculation that they observed in their patients could not be due to obstruction of the sperm core due to foreign-body reaction, since their patients were not sterile after the operation. Before attributing chronic and intermittent postoperative pain to central nervous system dysfunction, we should consider some simple facts and the craftsmanship that a surgeon should display. Dr. Robert Bendavid has shown us that dysejaculation pain is caused by kinking of the vas deferens. We also know that having one patient vas deferens is certainly sufficient to father a child. The physicians at the Shouldice Hospital have always stressed division of the genital branch of the genitofemoral nerve to prevent the development of chronic postoperative pain. The Lichtenstein hernia repair, as it is usually done, places mesh directly on top of this nerve. The vas deferens is frequently lying on top of the mesh. Whether mesh is used in an opened hernia repair or not, division of the genital branch of the genitofemoral nerve is an important aspect of opened inguinal hernia repairs which is often overlooked. In my own practice, I have frequently operated (using local anesthesia) on patients referred to me for chronic inguinal pain after hernia repair only to find the genital branch of the genitofemoral nerve involved in scarring wither from direct suturing or from mesh being placed on top of the nerve. It should be emphasized (especially at a teaching institution) that hernia repairs should be performed using local anesthesia. It is widely felt that hernia repairs done under local anesthesia have a much lower rate of chronic pain. This is understandable, since patients complain when a nerve whose presence is not appreciated by the surgeon is inadvertently incorporated into a repair. The surgeon can then adjust the placement of his suture, thus, saving the patient postoperative discomfort. Those who teach hernia repair should stress the pertinent anatomy of the groin and a meticulous technique using local anesthesia and including division of the genital branch of the genitofemoral nerve. In addition, transposition of the spermatic cord above the aponeurosis of the external oblique muscle (as Dr. E. Trabucco has suggested) would prevent adherence of the vas deferens and the spermatic vessels to any mesh placed on the floor of Hesselbach’s triangle.

The lumbar plexus (Figure 1) is formed by the anterior primary rami of L1-4 nerves. It lies within psoas major on the posterior abdominal wall. All nerves receive grey rami communicantes from the sympathetic trunk. From the plexus emerge: •the obturator nerve (L2-4), supplying the thigh adductors •the femoral nerve (L2-4), supplying iliacus and knee extensors •the lumbosacral trunk (L4-5), which descends over the sacrum to contribute to the sacral plexus •the ilioinguinal (L1) and the iliohypogastric nerves (L1), which obliquely traverse the abdominal wall muscles, supplying them and the inguinal and suprapubic skin •the lateral femoral cutaneous nerve (L2-3), entering the thigh just medial to the anterior superior iliac spine to supply the skin of the anterolateral surface of the thigh •the genitofemoral nerve (L1-2), supplying the skin of the genitalia and the femoral triangle.

Spermatic cord entrapment is an unusual complication of inguinal herniorrhaphy. The case of a 52-year-old man who presented with severe pain along the left spermatic cord and testicle, varicocele, and dyspareunia after a laparoscopic bilateral inguinal hernia repair performed elsewhere is reported. Medical treatment failed, and laparoscopic exploration showed the vas deferens and spermatic vessels entrapped by a mesh slit that was pulling the genital branch of the genitofemoral nerve. The vas deferens and spermatic vessels were released, neurotomy of the affected nerve branch was performed, and a new mesh was positioned in the residual space. The patient's pain disappeared completely after the surgery and the varicocele decreased progressively. The patient remains asymptomatic at 1-year follow-up. Laparoscopy might be the approach of choice to treat some of the complications of laparoscopic hernia repair, not only because it allows better observation of the anatomic structures, but also because the surgical therapy can be done with minimal tissue damage compared to the traditional approach.

Percutaneous Greenfield filter placement through a femoral vein approach resulted in errant retroperitoneal placement in a patient with pulmonary emboli. A properly positioned filter was then placed surgically through the right internal jugular vein. The patient subsequently required removal of the errant retroperitoneal filter because of genitofemoral nerve irritation. Problems associated with percutaneous Greenfield filter placement and pertinent literature are discussed. (J VASC SURG 1990;12:60-1.)

The spinal motonucleus of the genitofemoral nerve regulating scrotal temperature can also be related to prenatal and neonatal testicular descent by gubernacular change in rats, and a sexually dimorphic-like bulbocavernosus/dorsolateral motonucleus. There is a hypothesis that neonatal androgen affects these motonuclei, and induces development of sexual organs through neural stimulation. Until now, the accumulation of isotope-labelled androgen and the immuno-reactivity of androgen receptor protein in each sexually-dimorphic spinal motonucleus have been revealed in adult rats but they have not been established in rats during neonatal periods. To investigate the presence of the androgen receptor in spinal sexually-dimorphic motonuclei in the neonatal period, we evaluated the androgen receptor immunoreactivity of these motonuclei. In Sprague-Dawley male rats, the lumbar spinal cords were resected at postnatal days 3, 10 and 30, and stained immunohistochemically using polyclonal antibody of androgen receptor protein. The immunoreactivity of androgen receptor protein was observed in the cells of the genitofemoral motonucleus from the 13th thoracic to the 2nd lumbar spinal cord and the bulbocavernosus/dorsolateral motonucleus was observed from the 4th to 5th lumbar spinal cord in all age groups. The proportional areas of both motonuclei at days 3 and 10 on cross-section were larger than at day 30. The motonuclei at days 3 and 10 were similar in all age groups. With the above results, the presence of androgen receptor protein was confirmed in the genitofemoral and bulbocavernosus/dorsolateral motonucleus from neonate to day 30. The larger proportional area of these motonuclei in neonates may indicate an active role for these motonuclei during the neonatal period. Although the immunoreactivity does not directly imply the presence of a functional receptor, neonatal androgen could be responsible for the development of sexual organs through the spinal motonucleus.

Sexual dimorphism in the topographical organization of immunoreactive serotonergic fibers has been shown for the first time in the anterior column of the rat lumbar cord. A characteristic preferential arrangement of serotonergic fibers on the small cell column composed of anterior horn motoneurons, which have been proved to send their axons to the cremaster muscle, was demonstrated at the lumbar segments (L1-L2) of male rats, using the immunoperoxidase technique with antiserum against serotonin. A similar finding was also observed in female rats, but was less prominent than in males. Comparative analysis of the cell numbers and the size of neuronal somata of the aforementioned nucleus, done using retrograde transport of fluorescent dye (DAPI) via axonal fibers coursing down the genitofemoral nerve to the cremaster muscle, gave significantly larger values in males. The sexual difference in the serotonergic innervation pattern was, in consequence, surmised to be caused by the cytoarchitectonic contrast ascertained in the lumbar anterior column. Furthermore, there may be a striated muscle endowed with some active functions homologous to those of the male cremaster muscle in the female rat.

The effect of acute intravenous infusion of cyclosporine (10 mg/kg) on efferent renal and genitofemoral nerve activity and afferent renal nerve activity was studied in anesthetized rats. All animals were studied after unilateral renal denervation and extracellular fluid volume expansion. Activity of both efferent sympathetic nerves was increased significantly by cyclosporine infusion (renal, 69%; genitofemoral, 60%). Afferent renal nerve activity was increased 82% after cyclosporine (P less than 0.05). Urine flow rate and both absolute and fractional sodium excretion from the innervated kidney were reduced 50% after cyclosporine infusion (P less than 0.01). Absolute and fractional sodium excretion from the denervated kidney were significantly increased after cyclosporine. Infusion of vehicle had no significant effect on any measured variable in innervated or denervated kidneys. These studies demonstrate the capacity of cyclosporine to increase efferent sympathetic nerve activity and afferent nerve activity. It is also shown that sodium retention resulting from acute infusion of cyclosporine can be attributed to the increase in efferent renal nerve activity.

The ilioinguinal nerve was dissected in 196 adult human cadavers. A normal pattern of distribution, consistent with modern textual descriptions, was defined in 60% of inguinal regions. In 35% of the inguinal regions a previously undescribed aberrant course for the cutaneous component of the ilioinguinal nerve was observed in which it is incorporated within the genitofemoral nerve, entered the inguinal canal at the deep inguinal ring, coursed within the cremasteric layer and emerged into the subcutaneous tissue at the superficial inguinal ring on the dorsal side of the spermatic cord or the round ligament of the uterus. The cutaneous component of the ilioinguinal nerve is most frequently found on the ventral surface of the spermatic cord or round ligament during inguinal hernia operations thus an unrecognized aberrant course of this nerve within the spermatic cord is particularly susceptible to accidental trauma.

During the past 8 years, a total of 36 patients were diagnosed as having either ilioinguinal or genitofemoral neuralgia. A multidisciplinary approach (surgeon, neurologist, anesthesiologist) as well as local blocks of the ilioinguinal nerve or paravertebral blocks of L1,2 were essential to determine which nerve was likely to be entrapped. Seventeen of the 19 patients having a diagnosis of ilioinguinal neuralgia after previous inguinal herniorraphy were completely free of pain after resection of the entrapped portion of the nerve. Seventeen patients were diagnosed as having genitofemoral neuralgia after previous inguinal herniorraphy, blunt abdominal trauma, or another operation. Neurectomy of the genitofemoral nerve proximal to the entrapment controlled the persistent pain in 12 of 17 of these patients. Ilioinguinal or genitofemoral nerve entrapment neuralgias are rare complications of operations in the inguinal region. When the diagnosis is made by a multidisciplinary approach, neurectomy is frequently successful in relieving severe pain and paresthesias without serious morbidity.

The anatomical and biochemical features of primary sensory afferents and the peptidergic innervation of cremaster motoneuron efferents in the genitofemoral (Gf) nerve were analyzed in the rat using immunohistochemical, histochemical, retrograde tracing and lesion methods. Afferent fibers in the Gf nerve were shown to originate from neurons in L1 and L2 dorsal root ganglia (DRG) and to project to L1 to T12.5 in the spinal cord. Some of the DRG neurons giving rise to these fibers contained substance P (SP) or the enzyme fluoride-resistant acid phosphatase but none appeared to contain somatostatin. The dermatome area of the Gf nerve, as determined by plasma extravasation methods, was located in the rostral scrotal and adjacent abdominal region. Identification of cremaster motoneurons by retrograde labelling from the Gf nerve revealed these neurons to be located in the L1 to L2 spinal cord segment, to have prominent rostrocaudally oriented dendritic aborizations and to receive a rich innervation by fibers containing SP, thyrotropin-releasing hormone (TRH) or met-enkephalin (met-Enk). Lesion studies indicated the SP- and met-Enk-containing fibers to be supplied by local intraspinal systems and the TRH-containing fibers by supraspinal systems. In female rats, motoneurons corresponding to the male version of the cremaster motoneuronal pool were less developed and received far fewer peptidergic connections than that observed in males. The multiple neural systems innervating cremaster motoneurons together with sensory afferents in the Gf and other scrotal nerves are suggested to be involved in the contribution of cremaster muscles to thermoregulation of the scrotum.

Summary By means of the direct-colouring thiocholine-ferricyanide method—combined with polarization microscopy—cholinesterase activity has been identified and localized in mixed, motor and sensory nerves. Motor axons (rat genitofemoral nerve) contain exclusively acetylcholinesterase, while sensory axons (rabbit great auricular nerve) exhibit only occasional acetyl- and no non-specific cholinesterase activity. Unmyelinated fibres in the sensory nerve contain only non-specific cholinesterase. Unmyelinated fibres in motor and mixed (sciatic) nerves appear to exhibit both acetyl- and non-specific enzyme activity.

Background: Peroperative identification and subsequent division or preservation of the inguinal nerves during open hernia repair may influence the incidence of chronic postoperative pain. Methods: A systematic literature review was performed to identify studies investigating the influence of different types of nerve management. Results: Based on three randomized studies the pooled mean percentage of patients with chronic pain after identification and division of the ilioinguinal nerve was similar to that after identification and preservation of the ilioinguinal nerve. Two cohort studies suggested that the incidence of chronic pain was significantly lower after identification of all inguinal nerves compared with no identification of any nerve. Another cohort study reported a significant difference in the incidence of chronic pain in favour of identification and facultative pragmatic division of the genital branch of the genitofemoral nerve compared with no identification at all. Conclusion: The nerves should be identified during open hernia repair. Division of and preservation of the ilioinguinal nerve show similar results. Incidence of postoperative chronic pain may be decreased by preservation of inguinal nerves in open hernia repair. DOI: 10.3329/bja.v8i1.6108 Bangladesh Journal of Anatomy January 2010, Vol. 8 No. 1 pp. 39-42

The gubernaculum, which has an important role to play in testicular descent, is richly supplied by the genital branch of the genitofemoral nerve through its scrotal attachment. In neonatal rats the genitofemoral nerve overlying the psoas muscle was divided before inguinal descent would normally occur, and the effect of this procedure on subsequent testicular descent was observed. Denervation of the gubernaculum caused the testes to remain in the abdomen. The significance of this finding in the rat is that an intact genitofemoral nerve is an essential prerequisite for normal descent, perhaps by allowing the gubernaculum to evert.

In spina bifida there is a high incidence of cryptorchidism, particularly where the lesion is at or above L2. This article describes the location of the testis in 32 spina bifida patients and the effect of spinal cord transection in neonatal rats: both studies suggest that the spinal cord influences testicular descent. It is already established that androgens, an intact genitofemoral nerve, and the gubernaculum are essential for the transinguinal phase of testicular descent to occur. Yet the mechanism by which testosterone exerts its effect on the gubernaculum remains obscure. To account for all the observed phenomena we postulate that a spinal cord nucleus may exist that is sensitive to androgens and mediates impulses through the genitofemoral nerve to the gubernaculum. Neuronal modulation of the gubernaculum may induce testicular descent.

KOJIMA, M. and OHE, H. Experimental Study on the Regulation of Testicular Function by the Cremaster Reflex in Rats. Tohoku J. exp. Med., 1986, 150 (2), 175-180-The present study was performed to clarify the role of the cremaster reflex in regulating the testicular function in rats. The impairment of cremaster reflex by bilateral dissection of the genitofemoral nerves resulted in a decrease of testicular weight and degenerative changes of the semeniferous tubules in the rats kept in a cold room (4°C), but not in the rats kept at room temperature (22°C). The results indicate that the cremaster reflex contributes much to the temperature regulation of the testicle located within the scrotum.

The proximal and distal attachments of the gubernaculum were severed in neonatal rats to examine their role in testicular descent and their relationship to transection of the genitofemoral nerve, which prevents descent of the testis. In 34 of 82 animals proximal transection of the gubernaculum resulted in descent of the testis. In 18 animals the testis remained in the abdomen but in both groups the processus vaginalis developed, suggesting that failure of descent was accidental and not caused by scrotal maldevelopment. Distal transection resulted in failure of descent and prevented growth of the processus vaginalis in all 27 rats. These results suggest that distal transection of the gubernaculum is equivalent to division of the genitofemoral nerve, which supplies the gubernaculum through its distal attachment. Because denervation of the gubernaculum prevents the effect of androgens on gubernacular differentiation, the results suggest that testosterone acts via the nerve. The putative effect of androgens on the gubernaculum may be mediated indirectly by the central nervous system, rather than directly on the gubernaculum itself.

Electrical stimulation of the penis or the dorsal penis nerve causes bilateral contractions of the cremaster muscles in the acute spinal rat. An asynchronous discharge could also be recorded from the genitofemoral nerve innervating the cremaster muscles after a latency of about 10 msec. Stimulation to the central cut end of one of the genitofemoral nerves elicited no discharge at the contralateral genitofemoral nerve but inhibited the cremasteric reflex from a subsequent penis stimulation. Stimulation of a number of cutaneous and muscle nerves also resulted in inhibition with similar time courses. An inhibition from cutaneous stimulation was shown to be resistant to strychnine but was antagonized by picrotoxin. The cremasteric reflex in the rat was blocked by various central nervous system depressants.

It is known that hormones influence significantly the prostate tissue. However, we reported that mating induces an increase in androgen receptors, revealing a neural influence on the gland. These data suggested that somatic afferents (scrotal and genitofemoral nerves) and autonomic efferents (pelvic and hypogastric nerves) could regulate the structure of the prostate. Here we assessed the role of these nerves in maintaining the histology of the gland. Hence, afferent or efferent nerves of male rats were transected. Then, the ventral and dorsolateral regions of the prostate were processed for histology. Results showed that afferent transection affects prostate histology. The alveoli area decreased and increased in the ventral and dorsolateral prostate, respectively. The epithelial cell height increased in both regions. Efferent denervation produced dramatic changes in the prostate gland. The tissue lost its configuration, and the epithelium became scattered and almost vanished. Thus, afferent nerves are responsible for spinal processes pertaining to the trophic control of the prostate, activating its autonomic innervation. Hence, our data imply that innervation seems to be synergic with hormones for the healthy maintenance of the prostate. Thus, it is suggested that some prostate pathologies could be due to the failure of the autonomic neural pathways regulating the gland.Sabe-se que os hormônios influenciam significativamente o tecido prostático. Entretanto, nós demonstramos que o acasalamento induz um aumento nos receptores androgênicos, revelando uma influência neural sobre a glândula. Esses dados sugerem que os aferentes somáticos (nervos escrotal e genito-femural) e os eferentes autonômicos (nervos pélvicos e hipo-gástricos) poderiam regular a estrutura da próstata. Neste trabalho, avaliou-se a função destes nervos na manutenção da histologia da glândula. Dessa forma, os nervos aferentes e eferentes de ratos machos foram seccionados As regiões ventral e dorsolateral da próstata foram processadas para histologia. Os resultados mostraram que a transecção aferente afeta a histologia da próstata. A área alveolar diminuiu e aumentou na próstata dorsal e dorsolateral, respectivamente. A altura da célula epitelial aumentou em ambas as regiões. A desenervação eferente produziu alterações dramáticas na glândula prostática. O tecido perdeu a sua configuração e o epitélio tornou-se difuso e quase desapareceu. Assim, os nervos aferentes são responsáveis por processos espinhais que pertencem ao controle trófico da próstata, ativando sua inervação autonômica. Dessa forma, nossos dados sugerem que a inervação parece ser sinérgica com os hormônios para a manutenção saudável da próstata. Assim, sugere-se que algumas patologias prostáticas poderiam ser ocasionadas devido a falhas nas vias neurais autonômicas que regulam esta glândula.

During the past 7 years 30 patients were diagnosed as having either ilioinguinal or genitofemoral entrapment neuralgia. A multidisciplinary approach (surgeon, neurologist, and anesthesiologist), as well as local blocks of the ilioinguinal nerve and/or paravertebral blocks of L-1 and L-2 (genitofemoral nerve), were essential to determine accurately which nerve was specifically involved. Fifteen of the 17 patients (88%) diagnosed as having ilioinguinal neuralgia after previous inguinal herniorrhaphy are pain free after resection of the entrapped portion of the nerve. Thirteen patients were diagnosed as having genitofemoral neuralgia after previous inguinal herniorrhaphy, blunt abdominal trauma, or other surgery. Neurectomy of the genitofemoral nerve proximal to the entrapment controlled the persistent pain in 10 of 13 (77%) of these patients. Ilioinguinal or genitofemoral nerve entrapment neuralgias are rare complications of surgery in the inguinal region. When accurately diagnosed, neurectomy of the specific nerve is highly successful in relieving severe pain and paresthesia without significant morbidity.

• Genitofemoral neuralgia is a syndrome characterized by chronic pain and paresthesia in the region of genitofemoral nerve distribution. Genitofemoral nerve entrapment has been described after inguinal herniorrhaphy, appendectomy, and cesarean section. Failure to distinguish it from ilioinguinal nerve entrapment can result in unnecessary inguinal reexploration, or patients severely debilitated from chronic pain. We recommend that patients with persistent pain and paresthesia in the inguinal region following surgery should have a local ilioinguinal nerve block. If this is unsuccessful in affecting relief of symptoms, a paravertebral block of L-1 and L-2 should be considered. Using these two blocks, a rational decision can then be made to operate on either the ilioinguinal nerve or the genitofemoral nerve. We describe three cases of genitofemoral neuralgia treated by extraperitoneal excision of the genitofemoral nerve. (Arch Surg1984;119:339-341)