Cremasteric reflexes of boys with descended, retractile, or undescended testes: an electrophysiological evaluation

Dartos reflex as autonomic assessment in persons with spinal cord injury

Study design

Prospective clinical series.

Objectives

The dartos reflex (DR) produces unilateral elevation of the testis with vermicular contraction of the scrotal skin and penile retraction. It is a somato-autonomic reflex that depends on the T11-L2 sympathetic segment. Its presence was analysed in men with various levels and severities of spinal cord injury (SCI).

Setting

France.

Methods

Male patients with SCI undergoing urodynamic or sexual assessment were included. DR of the scrotum and penis were systematically assessed in addition to the usual neurological examination that included assessment of the autonomic system, cremaster, and sacral reflexes. The DR was evoked by applying a small ice pack on the scrotum, separately to each side.

Results

Forty-six patients were assessed. DRs were always present when the T11-L2 segment was intact above the lesion (low paraplegia below L2) or below the lesion in an upper motor neuron (UMN) syndrome (spastic paraplegia above T10). They were more pronounced in the case of UMN syndrome. In the case of lower motor neuron (LMN) syndrome that included the T11-L2 segment, DRs disappeared in all but one patient. Patients with a LMN lesion were more prone to retrograde or absent ejaculation, loss of psychogenic erection, and open bladder neck.

Conclusions

The DR is a valuable test for the assessment of the integrity and excitability of the T11-L2 spinal segment. It is easy to perform and is predictive of some aspects of sexual and bladder neck function in men. DR should be considered as an addition to the autonomic standards.

Electrophysiologic evaluation of cremasteric reflex in experimental orchitis

AIM

Absent cremasteric reflex (CR) is a well known but not reliable sign of testicular torsion. We hypothesized that CR can also be altered in other causes of acute scrotum in children. An experimental study was performed to evaluate the clinical and electrophysiological features of CR in orchitis.

METHOD

Eighteen Wistar albino rats were allocated into three groups: control (CG), sham (SG) and orchitis (OG). In CG, after anesthetization with ketamine hydrochloride, the medial site of the anterior superior iliac spine was stimulated to obtain CR electrophysiologically, and latency and duration were recorded with a needle electrode placed in the cremasteric muscle. Electrophysiologic evaluations were performed 24 h after injection of 0.1 ml of 10(6) cfu/ml Escherichia coli (0:6 strain) in 1 ml of physiologic saline into the right testicle in OG, and 1 ml of saline only in SG. All testicles were sampled to check for orchitis after the electrophysiologic evaluations.

RESULTS

CR was obtained in all rats in CG and in 83.3% and 66.6% in SG and OG respectively (p < 0.05). The latency of CR was significantly higher in OG (15.1 ± 0.9 ms) and SG (15.5 ± 1.2 ms) than CG (10.5 ± 0.7 ms) (p < 0.017). The duration of CR was 15.1 ± 3.2 ms in CG, 16.2 ± 4.9 ms in SG and 18.5 ± 3 ms in OG (p > 0.05). Histopathologic confirmation of orchitis was obtained in all testicle samples in OG, and number of neutrophils and total orchitis score was significantly higher in OG than the other groups (p < 0.05).

CONCLUSION

Electrophysiologic parameters of CR may be altered in orchitis. Prolonged latency of CR in orchitis may be due to inflammation of the genitofemoral nerve or cremasteric muscle.

An electrophysiologic evaluation of whether open and laparoscopic techniques used in pediatric inguinal hernia repairs affect the genitofemoral nerve

BACKGROUND

A prospective study was performed to evaluate the effect of inguinal hernia repairs on the genitofemoral nerve (GFN), and to compare postoperative electrophysiologic changes in the GFN of patients who had undergone either open or laparoscopic surgery.

METHODS

Seventy patients with a mean age of 6.48 ± 3.49 were enrolled in the study. Either open or laparoscopic techniques were used to operate on the patients' inguinal hernias. In all cases, bilateral GFN motor responses were investigated electrophysiologically using surface electrodes on three occasions: preoperatively, in the first month, and third month postoperatively. t-Tests were used to compare changes in the GFN.

RESULTS

Preoperative mean latency of the GFN in all groups was found to be significantly prolonged on the hernia side, compared with the non-hernia side (P = 0.01). Although no difference was observed in the latency levels of the GFN on the operated side at the preoperative and early postoperative stages, GFN latency levels decreased significantly in the late postoperative period in the laparoscopic group (P < 0.05). In the late postoperative period, amplitudes of GFN motor responses were significantly higher in the laparoscopic group than the open repair group (0.91 ± 0.11 mV and 0.57 ± 0.053 mV, respectively; P < 0.05).

CONCLUSION

Preoperative prolonged latency of GFN on the hernia side is likely to occur due to the pressure on the nerve caused by the hernia mass. By surgically removing the hernia mass, this buildup of pressure is prevented, decreasing the latency of the GFN. The significantly higher motor response amplitudes and decreased latency in the late postoperative stage for the laparoscopic group may be due to the fact that this technique is less invasive.

Retractile testes: a review of the current literature

The current evidence for the management of retractile testes is discussed in this review. Issues such as clinical definitions, natural history, possible outcomes and evidence for surgical intervention are evaluated. After reviewing the literature, the authors summarize that currently there is not enough evidence to warrant surgery for retractile testes, but rather a strategy of surveillance should be adopted.

Electrophysiologic evaluation of genitofemoral nerve in children with inguinal hernia repair

AIM

Genitofemoral nerve (GFN) injury may occur because of chronic pressure of hernia sac or surgical intervention. A prospective study was performed to evaluate GFN electrophysiologically in children with inguinal hernia repair.

METHODS

Children with inguinal hernia were evaluated for GFN electrophysiologically before and after (3-6 months postoperatively) inguinal hernia repair. Bilateral GFN motor response latencies and durations were investigated electrophysiologically by surface electrodes. Wilcoxon signed ranked test was used for statistical analysis, and P values lower than .05 was considered to be significant.

RESULTS

Eleven patients with a mean age of 4.45 +/- 2.16 were enrolled in the study. Mean latency of patients was 2.37 +/- 0.89 milliseconds preoperatively and 3.14 +/- 1.02 milliseconds postoperatively. Latency of GFN was found prolonged after hernia repair (P = .008). Duration of GFN motor response was 9.94 +/- 1.49 milliseconds and 11.18 +/- 2.44 milliseconds, respectively, in preoperative and postoperative recordings. There was no significant difference detected in mean durations (P > .05).

CONCLUSION

Latency of GFN may prolong after inguinal hernia repair. Prolongation of GFN latency may be the result of surgical injury during hernia repair and consequently also related with chronic groin pain.

Morphology and innervation of the human cremaster muscle in relation to its function

The electromyographic properties of the cremaster muscle (CM) are quite different from other skeletal muscles. It shows excessive spontaneous discharges, and the motor unit shape and firing frequency of the CM muscle differ from that of limb muscles. In this study, CM of six adult cadavers and six orchiectomy specimens were used to reveal the detailed histology of the muscle and provide an anatomophysiological explanation for these unusual electromyographic properties. Routine histochemical stains revealed the CM was composed of several distinct bundles of smooth and striated muscle fibers within connective tissue. The smooth muscle fibers that were more profuse than previously known and were not arranged in layers, but widely dispersed between striated muscle fibers. Bielschowsky silver staining technique, anti-neurofilament and anti-synaptophysin immunostaining showed the presence of multiple motor end-plates observed as a series of small dots or lines running along the striated muscle fibers and several nerve endings on a single muscle fiber. Myosin immunostaining confirmed the CM is a slow-twitch muscle, and alpha-actin smooth muscle immunostaining confirmed the presence of a large number of smooth muscle fibers. There were also small multipolar neurons forming nerve plexuses between smooth muscle fibers. Anti-GFAP immunostaining confirmed the presence of glial cells similar to astrocytes. In conclusion, the findings of this detailed anatomical study showed the CM, widely known as a striated muscle, contains a large number of smooth muscle fibers, and the spontaneous electromyographic discharges are due to the presence of multiple motor end-plates and dense innervation.

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.

Sensory, motor somatic, and autonomic neurons projecting to the porcine cremaster muscle

The location of sensory, somatic, and autonomic neurons projecting to the pig cremaster muscle (CM) was studied by means of the retrograde neuronal tracer Fast Blue (FB) technique. FB was randomly injected in the left CM of four impuberal pigs and serial sections of sensory and autonomic ganglia and spinal cord were examined under a fluorescence microscope. Additionally, some indications about the number and size of labeled neurons were given. Sensory pseudounipolar somata were located ipsilaterally in the L2-L6 and S1-S2 dorsal root ganglia, their total number ranging between 125 and 194, their mean diameter between 24 and 89 microm. Somatic multipolar motoneurons were located ipsilaterally in the L2-L4 neuromeres of the spinal cord, their total number ranging between 53 and 169, their mean diameter between 29 and 53 microm. Autonomic multipolar paravertebral ganglia neurons were located ipsilaterally from L1 to S4 and contralaterally from L2 to S2. Their total number ranged from 2,015 to 3,067 and their mean diameter between 25 and 55 microm. The multipolar caudal mesenteric ganglia neurons were located bilaterally, their total number ranging between 14 and 1,408 and their diameter from 22 to 39 microm. In two subjects only, multipolar neurons were also found ipsilaterally in the microganglia of pelvic plexus (2 and 13 neurons). Their mean diameter ranged between 28 and 54 microm. Our study documented that the CM-projecting neurons were located at different neural levels, with a predominance in the autonomic ganglia.

Dartos reflex: A sympathetically mediated scrotal reflex

The dartos muscle is a sympathetically innervated dermal muscle layer within the scrotum, distinct from the somatically innervated cremasteric muscle. We electrophysiologically demonstrate the presence of a dartos reflex (DR), which can be used to evaluate the thoracolumbar sympathetic and genitofemoral nerve pathways. In 20 healthy men, we evoked the DR by cutaneous stimulation of the thigh and recorded the resultant scrotal skin contraction. We recorded hand, foot, and perineal sympathetic skin responses (SSRs) as controls. The DR was reliable and reproducible, as were the SSRs. The mean left DR latency was 4.8 s (SD, 2.7 s) and right DR latency was 5.4 s (SD, 3 .4), both of which were longer than the mean hand, foot, and perineal SSRs (P < 0.05). An intact reflex arc reflects the integrity of the afferent and efferent branches of the genitofemoral nerve (T12-L2). The DR test can also be used to assess scrotal autonomic innervation. Abnormalities of dartos innervation may impact testis thermoregulation and spermatogenesis.

Central and peripheral motor conduction to cremasteric muscle

The few electrophysiologic studies of the cremasteric muscle (CM) have mainly been restricted to the cremaster reflex with no reference to central and peripheral nerve conduction to the muscle, probably for technical reasons.Twenty-six normal adult male volunteers were studied by transcranial magnetic cortical stimulation (TMS) and stimulation of thoracolumbar roots. The genitofemoral nerve (GFN) was stimulated electrically at the anterior superior iliac spine and a needle electrode was inserted into the CM for conduction studies. The motor latency to the CM from the cortical TMS ranged from 20 to 33 ms among the subjects (25.8 +/- 2.9 ms, mean +/- SD). Magnetic stimulation of the lumbar roots produced a motor response of the CM within 9.6 +/- 1.9 ms (range, 6-15). The central motor conduction time to the CM was 16.5 +/- 2.8 ms (range, 10-21). Stimulation of the GFN produced a compound muscle action potential with a mean value of 6.4 +/- 1.8 (range, 4-10) ms in 23 of the 26 cases. Thus, central motor nerve fibers to the CM motor neurons exist, and there may be a representation area for the CM in the cerebral cortex. The GFN motor conduction time to the CM may have clinical utility, such as in the evaluation of the groin pain due to surgical procedures in the lower abdomen.

Retractile testes: an outcome analysis on 150 patients

BACKGROUND/PURPOSE

Retractile testes are testicles that can be brought down into their normal position in the scrotum but then immediately retract upward and out of the scrotum. The purpose of this study is to provide data on the outcome of pediatric patients with retractile testes.

METHODS

A retrospective analysis was conducted on prospectively collected data on the outcome of 150 consecutive patients with retractile testis examined and followed up by one pediatric surgeon from April 1982 to April 1999, inclusive.

RESULTS

Age at presentation was 5.2 +/- 3.0 years, and follow-up duration was 3.8 +/- 3.0 years. The number of retractile testes was 205, right-sided for 58 patients (38.6%), left-sided for 37 (24.6%), and bilateral for 55 (36.7%). Family history of retractile testis was positive in 8 patients (5.3%). Thirty-four patients required surgery (22.7%); indication for surgery was given when retractile testes ascended and became cryptorchid or if testicular size decreased during follow-up. Orchidopexy was required more frequently (P <.001) in patients with an associated hernia (68.8% of cases) than in patients without hernias (9.2%). One patient with spontaneous testicular descent during follow-up had a testicular carcinoma.

CONCLUSIONS

These findings suggest that the majority of patients (77.3%) with retractile testes have a spontaneously favorable evolution by 14 years of age and do not require surgical treatment. The authors report the first case of testicular carcinoma in a patient with retractile testis, and this indicates that these patients should be followed up even after testicular descent.

The cremasteric reflex: a useful but imperfect sign in testicular torsion

The cremaster reflex has been reported to be absent in 100% of cases of testicular torsion, making it a useful sign in this difficult diagnosis. The authors report a case of surgically confirmed testicular torsion in which the cremasteric reflex clearly was present at presentation. The background of this sign and its utility in the evaluation of the acute scrotum are discussed.

Prevalence and characteristics of cryptorchidism in a Nigerian district

OBJECTIVE

To determine the prevalence and characteristics of cryptorchidism among primary schoolboys in a Nigerian district.

SUBJECTS AND METHODS

The district selected had 35 primary schools with 23,342 pupils, consisting of 11,275 girls and 11,967 boys. Using a cluster-sampling technique, five primary schools were visited; 1096 boys (aged 5-13 years) participated in the study, giving a sampling ratio of 1:11. The boys underwent a clinical examination of the groin, scrotum and abdomen.

RESULTS

Cryptorchidism was found in nine subjects, giving a prevalence rate of 0.82%. All the undescended testes were unilateral, of which five were right-sided. Eight of the testes were intracanalicular and one was at the external ring. There were no cases of orchidopexy.

CONCLUSION

The prevalence of cryptorchidism among primary schoolboys in this district of Nigeria was high, at eight per 1000. Delayed diagnosis and treatment remains a problem because of the prevailing socio-economic factors. However, the incidence of cryptorchidism was similar to that reported in other parts of the world.

Cremasteric reflex and retraction of a testis

PURPOSE

A clinical study has been planned to define the clinical characteristics of cremasteric reflex (CR) for deciding on the possibility of a prolonged suprascrotal stay of a testis through this reflex.

METHODS

Five hundred boys from 3 days to 16 years of age were divided into 6 groups according to their ages and were evaluated for the presence of the CR. After evoking CR, the presence or absence of changes in testicular location and the most elevated position of the testis were recorded. Testicular position difference (TPD), the duration of the stay of testis in the most elevated position (DEP), and the interval for reevoking the CR (IRCR) were determined. The number of consecutive responses after repetitive evokings were recorded as reproducibility (R). Mean TPD, DEP, IRCR, and R values for both sides were calculated and compared among groups. The boys with a positive reflex were classified further according to their TPD, DEP, IRCR, and R values. Three groups were established according to the aforementioned criteria by dividing the values into 3 equal parts. The association of each of the parameters to other parameters were compared.

RESULTS

Bilateral positive CR was encountered in 42.7% of newborns, 36.3% of the boys between 1 month and 1 year old, 38.1% of the boys between 2 years and 4 years old, 75.2% of the boys between 5 years and 8 years old, 70.3% of the boys between 9 years and 12 years old, and 72.1% of the boys between 13 and 16 years old. The highest percentage of the contralateral activations during ipsilateral evokings were encountered in boys who were between 5 and 8 years of age. The highest mean TPD and mean R, the longest mean DEP, and mean IRCR were encountered in boys between 5 and 8 years of age. Boys with the highest TPD did not have shortest IRCR and highest R values. Similarly, boys with the longest DEP or shortest IRCR and highest R values did not have the association of other parameters that would suggest a hypersensitivity.

CONCLUSIONS

The rate of presence and the characteristics of a positive CR vary largely. However, suprascrotal location of a testis for extended periods through the activation of this reflex does not seem to be likely. Instead of a hyperactive reflex, the clinical condition, so called the retractile testis, might have resulted through alterations within the cremaster muscle itself. J Pediatr Surg 36:863-867.

Cremaster muscle is not sexually dimorphic, but that from boys with undescended testis reflects alterations related to autonomic innervation

BACKGROUND/PURPOSE

The genitofemoral nerve and its motor neuron are known to be sexually dimorphic. An association has been suggested to exist between antiandrogen-induced undescended testis and the genitofemoral nerve. Therefore, the cremaster muscles (CM) from boys and girls with inguinal hernia and boys with undescended testis were compared to evaluate the failed descent through sexual dimorphism.

METHODS

Samples of CM were obtained from 10 boys and 10 girls with inguinal hernia and 10 boys with undescended testis. Sections were stained for ATPase reactions after acid and alkaline preincubations, and for the expression of myosine heavy chains. The percentages of type 1 and type 2 fibers, and mean diameters of fibers according to the types were determined for each group. Values were compared through Mann-Whitney U test, and P values less than .05 were considered to be significant.

RESULTS

CM have mainly been composed of type 1 fibers. Distributions of type 1 and 2 fibers have not shown a difference among groups. Mean diameters of both type 1 and type 2 fibers from girls (P < .05), and mean diameter of type 2 fibers from boys with undescended testis have been significantly smaller than those encountered in boys with inguinal hernia (P < .05).

CONCLUSIONS

Although the mean diameter of type 1 fibers from boys with undescended testis has been as large as those encountered in boys with inguinal hernia, mean diameter of type 2 fibers has been as small as those encountered in girls. Among various reasons to selectively diminish the size of type 2 fibers, lack of beta adrenergic effect appears to be the most satisfactory explanation. J Pediatr Surg 36:877-880.

Ultrastructural deficiency in autonomic innervation in cremasteric muscle of boys with undescended testis

BACKGROUND/PURPOSE

The cremaster muscles (CM) associated with undescended testis reveal neurogenic alterations that mainly affect type 2 fibers. The ultrastructure of CM has been evaluated to define if further evidence to explain the alterations could be identified.

METHODS

CM of 8 boys with inguinal hernia and 8 boys with undescended testis at similar ages were biopsied. Samples were processed for electron microscopic evaluations. Semithin and thin sections were examined under an electron microscope.

RESULTS

The CM associated with inguinal hernia showed normal ultrastructure. However, some alterations were encountered in CM associated with undescended testis. Unmyelinated fibers were diminished in number, and myelinated fibers were outnumbering the unmyelinated fibers. Marked disorientation of myofibers, redundant sarcolemma, empty sleeves of basal lamina, disarray of myofibrils, densely packed myofilaments, Z disk streaming, dilated sarcoplasmic reticulum, and dense-irregularly shaped mitochondria were repeatedly encountered. Satellite cells appeared inactive. Most of the fibers were contracted.

CONCLUSIONS

The decrease in number of unmyelinated fibers appears to represent a decrease in autonomic nerve fibers. The alterations within muscle fibers may reflect a deficiency in autonomic innervation. Autonomic nervous system is highly responsive to circulating androgens. Factors decreasing the vulnerability of autonomic nervous system against androgenic effects may result in a CM with neurogenic alterations, thus inhibiting testicular descent. J Pediatr Surg 36:573-578.

Distribution and morphometry of fiber types in cremaster muscles of boys with inguinal hernia or undescended testis

In the present study, we determined and compared the distribution and mean diameters of fiber in the cremaster muscles (CM) of boys with either inguinal hernia (IH) or undescended testis (UT). Samples of CM were obtained from 20 patients (10 boys with IH, and 10 boys with UT) of similar age. The CM muscles of two boys each, without inguinal pathology, were sampled during autopsy. Sections were stained for oxidative and glycolytic enzymes, as well as for ATP-ase reactions after acid (pH: 4.6) and alkaline (pH: 10.6) preincubations. Specimens were also analyzed morphometrically using a KONTRON 400 computerized image analysis system. The Mann- Whitney U test was applied to compare the percentages of fiber types and mean diameters of fibers according to the types of the CM of boys with IH or UT. In boys, the CM is mainly composed of type 1 fibers. The CMs of patients with UT reveal alterations of neurogenic origin. Although both type 1 and type 2 fibers reveal alterations, type 2 fibers appear to be affected more profoundly and characterized by significantly decreased mean diameters. Significantly decreased mean diameters of type 2 fibers in CM may support disuse, lack of sensitivity to the hormonal influences, or an alteration in the corticospinal tracts of boys with UT.

Cremaster muscles obtained from boys with an undescended testis show significant neurological changes

OBJECTIVE

To compare cremaster muscles (CMs) obtained from boys with inguinal hernia, hydrocele or an undescended testis and those obtained from girls with inguinal hernia, thus defining the changes associated with each clinical condition.

MATERIALS AND METHODS

CM samples were obtained from 26 boys and three girls with inguinal hernia, and 18 boys who had undergone surgery for an undescended testis (12) or hydrocele (six). The samples were frozen in isopentane cooled in liquid nitrogen and were processed for sectioning by cryostat. Sections (12 microm) were stained with a several histochemical stains. The presence of central nuclei, fibre splitting, basophilic fibres, fibre necrosis, inflammatory changes, small angular fibres, fibre hypertrophy, grouped atrophy, and endo- and perimysial fibrosis were evaluated. From each specimen, 200 fibres were also analysed morphometrically using a computerized image analysis system.

RESULTS

Neurogenic changes were apparent in all the CMs from patients with an undescended testis but none of the samples obtained from girls showed any changes. While only two specimens of 26 from boys with inguinal hernia (8%) had evidence of neurological alterations, eight CM (31%) had general changes. The mean (SD) fibre diameters did not differ significantly among the groups with inguinal hernia, hydrocele and undescended testis, at 23. 0 (8.6), 24.4 (4.5) and 23.0 (10.5) microm, respectively.

CONCLUSION

Cremasteric muscles associated with an inguinal hernia or an undescended testis differ; neurogenic changes were detected within all the CM of boys with an undescended testis. These changes in the CM may have influenced the location of the testis.

Lack of carbachol response indicates the absence of cholinergic receptors in sacs associated with undescended testis

BACKGROUND/PURPOSE

The mechanism of testicular descent remains controversial. The processus vaginalis (PV) contains smooth muscle and should have contractile activity that may contribute to descent. This study was designed to evaluate the smooth muscle of PVs associated with incomplete obliteration for spontaneous activities and responses to various stimuli, to determine if differences exist according to sex, diagnostic source, or location of the testis.

MATERIALS

Peritoneal samples (n = 4); sacs from girls (n = 8) and boys with inguinal hernia (n = 12); and sacs from boys with hydrocele (n = 3), hydrocele of the cord (n = 2), or undescended testis (n = 7) were used for the current study. Tissues were attached to the isometric force displacement transducer in an organ bath containing mammalian Ringer's solution at 37 degrees C. Spontaneous mechanical activity and contractile responses of tissues to the electrical field stimulation, phenylephrine, carbachol, and serotonin were recorded. The values obtained from boys and girls with inguinal hernia and from boys with either undescended or descended testis were compared through Fisher's Exact test.

RESULTS

There were no statistically significant differences in patient age between groups. Among the parameters studied, only the carbachol response of the sacs associated with undescended testis showed a significant difference compared with the others (P = .001). None of the sacs associated with undescended testis responded to carbachol, whereas all of the sacs from boys and girls with inguinal hernia responded to carbachol.

CONCLUSIONS

Lack of carbachol response suggests the absence of cholinergic receptors within the sacs associated with undescended testis. The lack of cholinergic receptors may play a role in the failure of the process of testicular descent by hindering either PV elongation into the scrotum or a possible propulsive activity of the PV on the testis.