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

Fascinating history of groin hernias: Comprehensive recognition of anatomy, classic considerations for herniorrhaphy, and current controversies in hernioplasty

Groin hernias include indirect inguinal, direct inguinal, femoral, obturator, and supravesical hernias. Here, we summarize historical turning points, anatomical recognition and surgical repairs. Groin hernias have a fascinating history in the fields of anatomy and surgery. The concept of tension-free repair is generally accepted among clinicians. Surgical repair with mesh is categorized as hernioplasty, while classic repair without mesh is considered herniorrhaphy. Although various surgical approaches have been developed, the surgical technique should be carefully chosen for each patient. Regarding as interesting history, crucial anatomy and important surgeries in the field of groin hernia, we here summarized them in detail, respectively. Points of debate are also reviewed; important points are shown using illustrations and schemas. We hope this systematic review is surgical guide for general surgeons including residents. Both a skillful technique and anatomical knowledge are indispensable for successful hernia surgery in the groin.

Sarco(endo)plasmic reticulum and plasmalemmal Ca(2+)-ATPase activities in cremaster muscles and sacs differ according to the associated inguinal pathology

Sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) and plasmalemmal Ca(2+)-ATPase (PMCA) activities in cremaster muscles and sacs, which have been subjected to different autonomic tonuses, were determined and compared. Samples of cremaster muscles and sacs associated with male or female inguinal hernia, hydrocele or undescended testis were obtained from children during operations and activities of SERCA and PMCA were determined. While highest SERCA and PMCA activities were encountered among cremaster muscles and sacs associated with undescended testis, least activities were encountered among structures associated with hydrocele. The alterations in SERCA and PMCA activities in cremaster muscles associated with undescended testis appear to reflect the attempts at maintaining the levels of cytosolic calcium. Despite similar total calcium contents, lower SERCA and PMCA activities were found in sacs associated with hydrocele compared to those associated with undescended testis suggest a difference among the levels of cytosolic calcium.

The role of sympathetic innervation in the developing rat gubernaculum

BACKGROUND

Testicular descent occurs in several steps, but the mechanism remains unknown. Recently, sympathetic nerves have been proposed to have a role. This study aimed to see if adrenergic agonists and antagonists affected the neonatal rat gubernacular cremaster sac in organ culture.

METHODS

Cremaster sacs were collected from 2-day-old Sprague-Dawley male rats (n = 90) and placed in organ culture with/without (1) calcium chloride (0.45-1.8 mmol/L), (2) rat calcitonin gene-related peptide (CGRP) (714 nmol/L), (3) nifedipine (0.1-100 nmol/L), (4) isopreneline (10 micromol/L), and (5) guanethidine (10 micromol/L). Gubernacula were observed over 2 days for rhythmic peristalsis (>120 beats per minute for >1 minute).

RESULTS

Addition of CGRP stimulated rhythmic contractility but only in the presence of calcium, with a dose-response to the level of calcium ions. Contractions induced by CGRP with calcium could be obliterated in a dose-response by nifedipine. Isoprenaline caused some increase in contractions with calcium but less than that seen with CGRP. No augmentation of effect was seen with CGRP and isopreneline together, and the level of contractility was the same with guanethidine.

CONCLUSIONS

Calcitonin gene-related peptide is the main effector for contractility of the rat cremaster sac, as long as calcium ions are present. Adrenergic agonists and antagonists had limited effects. Contractility could be inhibited with nifedipine, consistent with CGRP acting via a calcium-dependent pathway.

Testicular descent, cryptorchidism and inguinal hernia: the Melbourne perspective

Cryptorchidism is the commonest congenital genitourinary anomaly in males and results when the testis does not descend into its normal intrascrotal position during development. In full-term infants, the incidence is approximately 3% at birth. Cryptorchidism results in several abnormalities, including attenuated spermatogenesis, infertility and a greater risk of malignancy. The normal mechanism of testicular descent appears to be multi-staged, with various anatomical factors and hormonal influences, but the exact process is still unclear. In this article we review the current theories of normal testicular descent, with a focus on the hormones and anatomical factors, and current treatments for undescended testis.

Chemical sympathectomy by 6-OH dopamine during fetal life results in inguinal testis through altering cremasteric contractility in rats

BACKGROUND/PURPOSE

Androgens are proposed to influence testicular descent through modulating sympathetic tone. An experimental study was undertaken to evaluate the effects of prenatal chemical sympathectomy on testicular location associated with the alterations in contractile properties of cremaster muscles in rats.

METHODS

Time-mated pregnancies were started in 10 rats. Two groups, each receiving saline or 6-hydroxydopamine from day 15 to day 19 of intrauterine life were established. At 2 months of age, localization of testes were evaluated, cremaster muscles were removed, and contractile properties were studied. Twitch and tetanic contractions were recorded isometrically at 37 degrees C. Effects of verapamil, isoprenaline, and L-NNA were investigated. Results were compared through analysis of variance (ANOVA), and P values less than.05 were considered to be significant.

RESULTS

Both testes of all male offspring in the control group (n = 19) were in the scrotum. Six offspring among 17 subjected to 6-hydroxydopamine had undescended testes. Treatment with 6-hydroxydopamine had no effect on force-frequency relationship of cremaster muscle strips. Cremaster muscles of rats exposed to 6-hydroxydopamine had lower sensitivity to voltage-sensitive Ca++ channel blockade by verapamil (3 x 10(4) mol/L; P <.05). These muscles displayed greater contractile response to isoprenaline (10(-5) mol/L; P <.05) but not to nitric oxide synthase inhibition by N(omega)-nitro-L-arginine. Alterations in contractile properties of the muscles did not differ according to localization of testes among rats subjected to 6-hydroxydopamine.

CONCLUSIONS

Administration of 6-hydroxydopamine resulted in suprascrotally located testes. This localization has been associated with less exposure at sympathetic tonus. These findings support that sympathetic activity plays an important role in localization of testis.

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.

Differences in the morphology of the processus vaginalis with sex and underlying disease condition

The structures of sacs from boys and girls with inguinal hernia, and from boys with undescended testis or hydrocele were evaluated and compared. Particular attention was directed to determine if a clue helpful in describing the mechanism of obliteration of processus vaginalis (PV) exists. Sacs from boys (n: 8) and girls (n: 11) with inguinal hernia, and sacs from boys with undescended testis (n: 11) and hydrocele (n: 10) were obtained and stained with hematoxylin-eosin, trichrome and elastic van Gieson. The histologic structures of each group of samples were determined and compared. Smooth muscle was presented as a layer within the sacs of girls and boys with inguinal hernia. However, smooth muscle bundles were sparsely presented in sacs associated with undescended testis and hydrocele. Myofibroblasts were commonly encountered in sacs associated with inguinal hernia. The smooth muscle was invariably presented in sacs that contained myofibroblasts. While sacs from boys only had smooth muscle, sacs from girls also had striated muscle. Since the muscle components of sacs vary, PV is sexually dimorphic. Persistence of PV seems to be associated with the presence of smooth muscle and myofibroblasts within the sac wall. Myofibroblasts may have originated from the smooth muscle, and reflect the attempts at obliteration of PV.

Excessive sac pressures: the pathogenesis and innocence of hydroceles in children

OBJECTIVE

To determine whether paediatric hydroceles result entirely from a small-calibre patent processus vaginalis, allowing free communication between the abdominal cavity and hydrocele sac, or whether there are other mechanisms.

PATIENTS AND METHODS

Twenty-five hydroceles were studied prospectively in 24 boys (aged 18-132 months). Consent for the intraoperative measurements was obtained before surgery. The hydrocele was repaired under general anaesthesia with endotracheal intubation, using a standard approach, taking care not to open the sac during mobilization. Intra-abdominal pressures during surgery were measured indirectly via a nasogastric tube after gastric decompression. The pressure in the sac was measured via a 20 G intravenous cannula inserted via a purse-string suture. The relative pressure was then calculated by subtracting the intra-abdominal from the sac pressure. The effects of age and laterality were evaluated.

RESULTS

The median (range) intra-abdominal, sac and relative pressures were 8 (2-18), 11 (3-30) and 4 (3-30) cmH2O, respectively. The sac pressure in the sac was greater than the intra-abdominal pressure in 17 of 25 (68%; P = 0.004) patients. Age or laterality had no significant influence on any of the pressures.

CONCLUSIONS

These results suggest that in a significant proportion of hydroceles in children the pressures are higher than the intra-abdominal pressure. Therefore, they cannot be explained simply as a freely communicating, narrow-calibre processus. In addition, the pressures may reach levels which are potentially damaging to the testis.

Myofibroblasts defined by electron microscopy suggest the dedifferentiation of smooth muscle within the sac walls associated with congenital inguinal hernia

OBJECTIVE

To ascertain the presence of myofibroblasts in sacs associated with inguinal hernia in children, through an ultrastructural evaluation using electron microscopy.

MATERIALS AND METHODS

Sacs were obtained from 10 boys and 10 girls (of similar age, approximately 45 months) with inguinal hernia and processed for electron microscopy. Thin sections were examined specifically for the presence of myofibroblasts.

RESULTS

The ultrastructural evaluation showed myofibroblasts with classical electron microscopic features within all of the sacs, regardless of the gender of origin.

CONCLUSION

The persistence of smooth muscle hinders the obliteration of the processus vaginalis; myofibroblasts are found in association with smooth muscle and thus such cells within the sac walls seem to originate from the smooth muscle, reflecting the dedifferentiation of smooth muscle. This dedifferentiated state may represent attempted apoptosis, which usually causes the disappearance of the smooth muscle and obliteration of the processus vaginalis after the descent of the testis into the scrotum.

Individual and associated effects of length of inguinal canal and caliber of the sac on clinical outcome in children

PURPOSE

The caliber of processus vaginalis is accepted to define the clinical outcome to be an inguinal hernia or hydrocele not based on any evaluation. The caliber of sacs and length of inguinal canals of boys and girls were evaluated to define the relation of sex, age, and the diagnosis with caliber of the sac and the length of inguinal canal.

METHODS

A total of 217 inguinal canals in 24 girls and 112 boys with inguinal hernia, 30 boys with hydrocele or hydrocele of the cord, and 31 boys with undescended testis have been evaluated. Twenty patients had bilateral involvement. The length of inguinal canal, and the circumference of the sac were measured. A formula was developed to predict the length of inguinal canal according to the age and sex. The circumferences of the sacs, length of inguinal canals, and the ratios of the circumference to the length were compared according to the clinical pictures.

RESULTS

The regression model of the relationship between the age and the length of the inguinal canal is an equation of third degree (inguinal canal in millimeters) = 0.0000119 x age 3 (months) - 0.00292 x age 2 (months) + 0.3168 x age (months) + 19.979 (r2 = 0.47). Inguinal canal is longer in boys (25.133 and 27.996 mm; P = .018), and length does not differ among diagnoses but differs according to age showing a linear growth after 24 months. Although the circumference as a sole parameter could classify only 55.3% of boys correctly, the ratio of length of inguinal canal to circumference of the sac has been the significant parameter in classifying boys into 1 of 3 groups including inguinal hernia, undescended testis, and hydrocele with a 70.2% success rate.

CONCLUSIONS

Inguinal canal that shows a linear growth after 24 months of age is longer in boys. Caliber is not the unique factor that determines the clinical outcome. Although the ratio of length of inguinal canal to the circumference of the sac defines the clinical picture best, even this parameter cannot classify the cases correctly. Therefore, some factors in addition to the caliber and length of inguinal canal might have roles in determining the clinical outcome.

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.