Experimental testicular torsion and its effects on the contralateral testicle

Objective Following experimental unilateral torsion of the testis the histologic effects of unilateral testicular torsion on the contralateral testis were investigated. Materials and methods Utilizing detorsion or orchiectomy at 4 hours and 8 hours after torsion, the effects of early and late treatment modalities on the contralateral testicle were observed. Results Morphometry of the contralateral testis revealed some alterations including focal sclerosis, decrease in mean seminiferous tubular diameter and a marked increase of the Leydig cells in some subgroups. Conclusion In spite of some changes, definite evidence for contralateral damage due to ipsilateral torsion contributing to male infertility was hardly observed.     

Flow cytometric DNA analysis demonstrates contralateral testicular deterioration in experimental unilateral testicular torsion of prepubertal rats

Summary. It has been postulated that unilateral testicular torsion causes damage to the contralateral testis and reduces fertility. However, in animal studies such an effect has not been fully proven by histopathologic examination or other conventional assays of spermatogenesis. We investigated the effect of unilateral testicular torsion on contralateral spermatogenesis in prepubertal rats using quantitative flow cytometric DNA analysis. Male rats were divided into three groups which underwent sham-operation, simple hemiorchiectomy or unilateral testicular torsion. Five weeks after these operations, fertility and spermatogenesis by flow cytometry were evaluated. No significant differences were observed in body weight, contralateral testicular weight or serum testosterone concentration among the three experimental groups. In the torsion group, mean seminiferous tubular diameter, number of foetuses, fertility rate and percentage of haploid cells were all significantly decreased compared to the other two groups. These results suggest that unilateral testicular torsion causes damage to the contralateral testis and consequently can reduce the future fertility of prepubertal rats.     

Protective role of erythropoietin during testicular torsion of the rats

Testicular torsion is an important clinical urgency. Similar mechanisms occurred after detorsion of the affected testis as in the ischemia reperfusion (I/R) damage. This study was designed to investigate the effects of erythropoietin (EPO) treatment after unilateral testicular torsion. Fifty male Sprague-Dawley rats were divided into five groups. Group 1 underwent a sham operation of the right testis under general anesthesia. Group 2 was same as sham, and EPO (3,000 IU/kg) infused i.p., group 3 underwent a similar operation but the right testis was rotated 720° clockwise for 1 h, maintained by fixing the testis to the scrotum, and saline infused during the procedure. Group 4 underwent similar torsion but EPO was infused half an hour before the detorsion procedure, and in group 5, EPO was infused after detorsion procedure. Four hours after detorsion, ipsilateral and contralateral testes were taken out for evaluation. Treatment with EPO improved testicular structures in the ipsilateral testis but improvement was less in the contralateral testis histologically, but EPO treatment decreased germ cell apoptosis in both testes following testicular IR. TNF-α, IL-1β, IL-6 and nitrite levels decreased after EPO treatment especially in the ipsilateral testis. We conclude that testicular I/R causes an increase in germ cell apoptosis both in the ipsilateral and contralateral testes. Eryhropoietin has antiapoptotic and anti-inflammatory effects following testicular torsion.     

Reperfusion injury after detorsion of unilateral testicular torsion

Summary Reperfusion injury has been well documented in organs other than testis. An experimental study was conducted to investigate reperfusion injury in testes via the biochemical changes after unilateral testicular torsion and detorsion. As unilateral testicular torsion and varicocele have been shown to affect contralateral testicular blood flow, reperfusion injury was studied in both testes. Given that testicular blood flow does not return after 720° testicular torsion lasting more than 3 h, the present study was conducted after 1 and 2 h of 720° torsion. Adult male albino rats were divided into seven groups each containing ten rats. One group served to determine the basal values of biochemical parameters, two groups were subjected to 1 and 2 h of unilateral testicular torsion respectively, two groups were subjected to detorsion following 1 and 2 h of torison respectively, and two groups underwent sham operations as a control. Levels of lactic acid, hypoxanthine and lipid peroxidation products were determined in testicular tissues. Values of these three parameters obtained from the sham operation control groups did not differ significantly from basal values (P>0.05). All three parameters were increased significantly in both ipsilateral and contralateral testes after unilateral testicular torsion when compared with basal values (P<0.01 and P<0.05, respectively). Detorsion caused significant changes in lipid peroxidation products levels in ipsilateral but not in contralateral testes when compared with values obtained after torsion (P<0.01 and P>0.05, respectively). It is concluded that ipsilateral testicular torsion causes a decrease in perfusion not only in the ipsilateral but also in the contralateral testis. Additionally, detorsion following up to 2 h of 720° torsion causes reperfusion injury in ipsilateral but not in contralateral testis.     

Unilateral testicular disease: effect on the contralateral testis (morphometric study)

Unilateral testicular disease has been reported to damage the contralateral testis. In order to find out whether this detrimental influence is permanent in nature or can be avoided by therapeutic measures, and furthermore to quantify the damage, the following experiments were performed. Seventy-five rats were classified into the following five groups: I) testicular torsion persisting for eight hours; II) ipsilateral semicastration after torsion persisting for eight hours; III) semicastration; IV) sham operation as control; V) immunosuppression with azathioprine after torsion persisting for eight hours. The contralateral testes were removed two months later and perfused with fixative via the testicular artery. Stereologic techniques were employed to obtain quantitative morphologic data. Serum hormone levels were determined. The volume density of the contralateral germinal epithelium was not decreased two months after torsion for eight hours, torsion following by semicastration or torsion followed by immunosuppression. The same was true of the total volume of germinal epithelium per rat testis. The hormone levels remained essentially unchanged.     

Activation of endothelial nitric oxide synthase in contralateral testis during unilateral testicular torsion in rats

There are controversies about the injury of the contralateral testis during unilateral testicular torsion (UTT). An autonomic reflex arc between bilateral testes has been proposed. The authors focused on the involvement of nitric oxide (NO) in the contralateral testis during UTT. Eight-week-old male Wistar rats underwent unilateral torsion (1 h)-detorsion (up to 24 h). NO synthase (NOS) activity was detected as NADPH-diaphorase activity after fixation by paraformaldehyde. N-nitro-L-Arginine methyl ester (L-NAME, 20 mg/kg) was injected intravenously to the other group of rats. To evaluate the testicular injury, proteolysis of alpha-fodrin production was detected by Western blotting. Apoptosis of the germ cells was evaluated by TUNEL. Long-term effect on spermatogenesis was evaluated by flow cytometry at 60 days after UTT. Transient activation of NOS was detected following the proteolysis of alpha-fodrin in the contralateral testis. L-NAME inhibited these alterations. NADPH-diaphorase activity and eNOS immunoreactivity were co-localized in the endothelial cells. These reactions were not observed in other organs. There was neither enhanced apoptosis nor deteriorated spermatogenesis in the contralateral testis during and 60 days after UTT. In the contralateral testis, eNOS-derived NO regulates the vasomotor function against unilateral testicular torsion, whereas it acts slightly cytotoxic. These results suggest the possible involvement of a testis-specific neurovasomotor reflex between the bilateral testes.     

Valoration of the FAS in the contralateral testis after unilateral testicular torsion. Experimental study in rats

The role the FAS and BCL-2 in the apoptosis of testicular cells in the contralateral testis after unilateral testicular torsion, was investigated. We compared with control group. These experiments were performed in male Wistar rats prepuberal old. FAS and BCL-2 determination is realized in cells cultures of contralateral testis. Flow cytometry and immunohistochemistry studies, using a FAS and BCL-2 specific monoclonal antibody, were utilized to value FAS y BCL-2 expression on testiculaires cells following unilateral testicular torsion. We observed an increase of expression of FAS and decrease of BCL-2 in the contralateral testis in comparison with control group. The present results may indicate that the expression of this molecules is implicated in cellular apoptosis.     

New animal model to evaluate testicular blood flow during testicular torsion.

BACKGROUND/PURPOSE: Unilateral testicular torsion is known to cause infertility because of damage to the contralateral testis. Testicular damage has been attributed to many different mechanisms, one of which is altered contralateral blood flow. In our experiment, in an effort to identify the reason for contralateral testicular injury, the authors developed an accurate method of measuring blood flow in both testes before, during, and after unilateral torsion. METHODS: Four- to 6-week-old piglets weighing 4 to 6 kg were studied. The animals were anesthetized, intubated, ventilated, and catheterized for vascular access. Piglets were assigned randomly to a sham group or a group undergoing 360 degrees or 720 degrees torsion of the left testis (n = 5 per group) for 8 hours, after which it was untwisted. Data were collected at baseline (T = 0), 8 hours of torsion (T = 8), and 1 hour after detorsion (T = 9). Mean arterial blood pressure and heart rate were monitored continuously. Testicular blood flow was determined using radiolabeled microspheres. Blood flow data were evaluated by analysis of variance. RESULTS: In the 360 degrees torsion group, blood flow changes were insignificant during torsion and after detorsion. In the 720 degrees torsion group, blood flow to the twisted testis was reduced significantly, whereas the contralateral testis was unaffected. One hour after detorsion, blood flow to both testes was increased significantly. CONCLUSIONS: The authors describe a new animal model to evaluate testicular blood flow during and after testicular torsion. Increased blood flow after detorsion may be the cause of testicular damage in patients with unilateral testicular torsion.     

Effect of testicular torsion on the contralateral testis

It has been previously shown that unilateral testicular torsion can cause disruptive anatomic changes in the contralateral testis in rats [1]. In this experimental study plasma and urine prostaglandin E2 levels were studied correlatively with testicular histopathology in acute testicular torsion cases. As a result of this study, necrobiotic morphologic alterations causing testis necrosis and significant increase in plasma prostaglandin E2 levels were observed. Contralateral testicular histology was analyzed in all dogs. None of them showed abnormal tubular architecture.     

Testicular torsion: Evaluation of contralateral testicular histology

Infertility may occur in patients with unilateral testicular torsion whose contralateral testis is intact. Depending on this observation, the physicians have begun to examine the contralateral testis. In the present prospective study we aimed to examine the histopathologic alterations occurring in the contralateral testicle with time. Sixty adult male albino rats were included in the programme, and following experimental torsion the histopathologic findings, especially those in the contralateral testis, were evaluated after 4–12 weeks. Long-term and high degree torsion of the testicle led to varying degrees of deterioration in the germinal epithelium and interstitial cells of the contralateral testicle. Histopathologic alterations were reversed in 12 weeks. Tubular diameter and testicular volume also decreased in accordance with the histopathologic alteration. In our opinion, orchiectomy following torsion of one testicle will limit potential histopathologic alterations in the contralateral testicle.     

Morphological changes in the contralateral testis in patients with testicular tumor

Biopsy of contralateral testis of 20 patients with an unilateral testicular tumor was carried out to evaluate the morphological changes of the contralateral testis caused by the tumor. Serum beta-chorionic gonadotropin (beta-hCG), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and alpha-fetoprotein (AFP) levels before orchiectomy were examined as a function influencing morphological changes of the contralateral testis. Typical carcinoma in situ was found in a case of ipsilateral testis. The presence of a few atypical germ cells, however, was the only finding of the contralateral testis of three patients. Five of 20 patients revealed hypospermatogenesis in the contralateral intact testis. Most of the other patients also showed sloughing of germinal epithelium suggesting disorder of spermatogenesis. Johnsen's mean score count and tubular wall thickening were related to neither clinical stages, ESR, serum beta-hCG, AFP, LH nor FSH levels. Tubular wall thickening was observed in 8 of 10 patients with a tumor weighting over 150 g, but was found in only 1 of 10 patients with a lighter tumor (p less than 0.01).     

Effect of unilateral testicular torsion on blood flow and histology of contralateral testes.

BACKGROUND/PURPOSE: Infertility occurs in 25% of patients after unilateral testicular torsion; hence, the authors examined hemodynamic and histological changes in both testes after acute testicular torsion in neonatal piglets. METHODS: The animals were anesthetized, intubated, ventilated, catheterized, and assigned randomly to a sham group or one of three experimental groups undergoing 720 degrees torsion of the left testis for 8 hours after which it was untwisted in group I and removed in group II. In group III, both testes were removed. Data were collected at baseline (T = 0), 4 hours (T = 4), and 8 hours of torsion (T = 8) and at the ninth hour of the experiment (T = 9). Testicular blood flow was determined by using radiolabeled microspheres. The testes also were examined blindly with routine and electron microscopy. RESULTS: In group I, testicular blood flow decreased in the affected testis during torsion and increased significantly after detorsion, whereas blood flow to the contralateral testis increased significantly after detorsion. Sham-operated animals showed no histological abnormality in either testis. In all torsion groups, the affected testis showed extensive changes caused by hemorrhagic necrosis. The contralateral testis only showed changes in group I. CONCLUSION: Unilateral testicular torsion resulted in ipsilateral damage caused by a decrease and subsequent increase in blood flow while in the contralateral testis; damage was the result of a significant increase in blood flow after detorsion.     

Exocrine and endocrine testicular function following unilateral torsion--a retrospective clinical study of 36 patients

Of 86 patients who had undergone unilateral testicular torsion the fertility in 36 patients could be examined 1-9 years later. The testis in 27 patients (= 75%) was surgically untwisted. Of 9 patients (= 25%) the testis was removed because of marked hemorrhagic infarction. Fixation of the contralateral testis was prophylactically performed in all cases. The testis of all patients who had undergone the detorsion within the first 22 h were saved and there was no significant difference of the testicular volume compared with the contralateral side. An atrophy of the contralateral testis following prophylactical fixation was never observed. In most of the 36 patients the fertility was diminished: Seminal analysis revealed an oligozoospermia in 44%, a teratozoospermia in 20%, an asthenozoospermia in 20% and a normozoospermia in 16% only. This result was independent of the duration of the torsion. There was no difference in the group of patients with detorsion and the group with orchidectomy. The endocrinological examination revealed a statistically significant correlation between FSH and sperm density and between FSH and the duration of the torsion. But both correlation coefficients were less than 0.5 and are therefore without any clinical relevance. Testosterone, LH and prolactin were normal in all cases.     

一侧睾丸扭转对对侧睾丸组织发育的影响

目的:研究一侧睾丸扭转以后对对侧睾丸组织的影响。方法:以大鼠为研究对象,按扭转时间及药物应用情况进行分组。在一侧睾丸扭转以后2个月,观察对侧睾丸曲细精管的变化。结果:一侧睾丸扭转2h以内,对侧睾丸曲细精管管腔和生精上皮增生;扭转6 h以后,曲细精管管腔和生精上皮萎缩;扭转6h以内应用别嘌呤醇能缓解对侧病变。结论:一侧睾丸扭转可以使对侧睾丸组织发育发生病理改变。     

Blood perfusion of the contralateral testis evaluated with contrast-enhanced ultrasound in rabbits with unilateral testicular torsion

The changes of blood perfusion of contralateral testis after unilateral testicular torsion remain controversial. In this study, 28 New Zealand white male rabbits were randomly divided into five groups. Group A (n = 8), the control group, underwent a sham operation on the unilateral testis without inducing testicular torsion. In groups B, C, and D (n = 5 each), unilateral testicular torsion was induced, and, after 3, 6 or 24 h, respectively, detorsion was performed. In group E (n = 5), permanent unilateral testicular torsion was applied. Contrast-enhanced ultrasound was used to observe the blood perfusion of the contralateral testis at the following stages: pre-torsion (preopration), immediately post-torsion (postopration), pre-detorsion, immediately post-detorsion, and late-stage post-detorsion (6–12 h post-detorsion in groups B–D) or at a similar time point (15–21 h post-torsion in group E). Time-intensity curves were generated, and the following parameters were derived and analyzed: arrival time, time to peak intensity, peak intensity, and half-time of the descending peak intensity. The analysis revealed that blood perfusion of the contralateral testis increased immediately after testicular torsion on the opposite side (P < 0.05), which increased with prolonged testicular torsion of the other testis. This research demonstrated that contrast-enhanced ultrasound was valuable in evaluating blood perfusion of the contralateral testis after unilateral testicular torsion.     

Acute experimental testicular torsion. No effect on the contralateral testis

Other investigators have shown that chronic unilateral testicular torsion produces negative effects on the contralateral testis in experimental animals. In the present study, bilateral testicular weight and histology, and concentrations and motility of spermatozoa from the cauda epididymidis were studied after 0 to 4 hours of acute unilateral testicular torsion in the rat. The obstruction of blood flow by torsion was documented, as well as the presence or absence of return blood flow after the relief of torsion. The above mentioned parameters of testicular function were studied at 7, 30, and 60 days after relief of torsion. Ipsilateral testis weights and epididymal sperm concentrations and motility were significantly reduced by 1, 2, and 4 hours of torsion. The histology of torsioned testes was also severely altered, and no seminiferous epithelial repair was evident 60 days after torsion. Contralateral testicles were not affected by ipsilateral torsion of 1, 2, or 4 hours duration, despite the fact that the ipsilateral testis function was completely compromised by 2 and 4 hours of torsion. These results indicate that there would be no clinical benefit in removing the acutely torsioned testis of Sprague-Dawley rats since it poses no threat to the contralateral testis.     

新生儿睾丸扭转8例诊治分析

目的 探讨新生儿睾丸扭转临床特点及诊治方法.方法 回顾性分析我院近5年收治的8例睾丸扭转新生儿的临床资料并复习相关文献.结果 新生儿睾丸扭转共8例;年龄7h~8d;左侧3例,右侧5例;入院查体均发现阴囊肿大呈暗红色或黑紫色,内可及质硬包块,触痛阳性;超声检查示患睾增大、密度不均、血流信号减少或消失;均行阴囊探查术,术中均发现精索睾丸扭转并已坏死,7例行患睾切除;病理结果示睾丸大片出血坏死,5例择期行对侧睾丸固定术.所有患儿随诊3~12月,1例家长拒绝切除患睾的患儿3月时B超复查已经萎缩,超声检查均未发现对侧睾丸异常.结论 新生儿睾丸扭转的睾丸坏死率极高;当发现新生儿阴囊色泽改变、肿大触痛等改变,在不能除外睾丸扭转时应尽早行阴囊探查术.     

Histological and immunohistochemical studies on the damage of contralateral testis following the unilateral testicular torsion in Wistar rats

The effect of experimental unilateral torsion of the testis on the contralateral intrascrotal testis in Wistar rats was evaluated histologically and immunohistochemically. The results were summarized as follows. 1) Histological damage of the seminiferous tubules in the contralateral testis was present only in adult rats. 2) The histological change 3-5 weeks after the experimental torsion consisted of marked decrease of spermatocytes, loss of spermatids and spermatozoa and numerous Sertoli-cell only tubules. Hyperplasia of the interstitial cells was demonstrated without thickness of the basement membrane and infiltration of the inflammatory cells. The tubular diameter and the ratio of contralateral testicular weight to rat body weight were significantly decreased (p less than 0.05) in torsion group. 3) Using an indirect immunofluorescent method, the positive immunohistochemical staining on spermatid and spermatozoa of normal testicular tissue was demonstrated using only the serum of rat with histological damage on the contralateral testis. Therefore, the phenomenon may be ascribable to the presence of antisperm antibody. It is concluded that the mechanism of the damage in seminiferous tubules of the contralateral testis with experimental torsion in adult Wistar rats is related to the humoral immunity producing antisperm antibody.     

On unilateral testicular and epididymal torsion: no effect on the contralateral testis

It is often stated that unilateral testicular torsion results in damage to the contralateral testis; however, there are a growing number of experimental and clinical papers which suggest this is not so. Conflicting results from experimental studies confuse the issue and may be due, among other things, to some specifics of the experimental model. In the present paper, we have examined bilateral rat testes 30 and 60 days after 720 degrees torsion to determine 1) the effect of unilateral testicular torsion with and without the inclusion of epididymal torsion, 2) the effect of relatively chronic torsion (24 hr., 10 day) versus relatively acute torsion (two hr., four hr.), and 3) the effect of establishing the model using scrotal surgery versus using an abdominal approach. Bilateral testicular histology, testis wt. (gm.), cauda epididymal sperm concentrations (sp./ml.), and cauda sperm motility scores (0-4) were examined. Ipsilateral testicular torsion or testicular plus epididymal torsion of two hr. or four hr. duration significantly reduced (p less than .05) ipsilateral testis weights, sperm concentrations, and motility scores, and disrupted normal tissue histology. Contralateral testicles were not altered. Epididymal ischemia alone produced no significant ipsilateral or contralateral effects. Chronic torsion (one day, 10 days) also destroyed ipsilateral testis function without altering the contralateral testicles. The occult cryptorchidism associated with the scrotal approach to establishing the torsion model had no effect on contralateral testicles. In no group, using either Lewis rats or Sprague-Dawley rats, were contralateral testicles altered by unilateral testicular torsion. These results plus recent clinical reports indicate that contralateral testicular damage due to ipsilateral torsion is hardly a proven phenomenon, let alone a significant factor contributing to male infertility.     

Contralateral genitofemoral sympathetic nerve discharge increases following ipsilateral testicular torsion

The decrease in blood flow due to the activation of sympathetic system has been suggested to play a role in contralateral testicular deterioration associated with unilateral testicular torsion. Sympathetic nerve discharges (SND) from the genitofemoral nerve were evaluated before and during unilateral testicular torsion. Under urethane anesthesia, arterial blood pressure and SND from splanchnic and right genitofemoral nerves were recorded in 12 male Sprague-Dawley rats, 8 of which were included in subsequent analyses. After control recordings of basal discharges for 2 min the left testis was twisted 720 degrees counterclockwise, and recording was resumed for an additional 30 min. Changes in nerve activity were calculated by measuring the area under the autospectrum curve, and alterations were compared. Following testicular torsion no significant changes were obtained for splanchnic SND, but the amplitude of SND from contralateral genitofemoral nerve showed an overall increase of 21.20+/-7.03% in six rats. This increase lasted about 10-15 min and activities returned to pretorsion levels. In two other rats no significant change was observed in either splanchnic or genitofemoral SND. Ipsilateral testicular torsion results in a transient increase in genitofemoral SND. A possible autonomic reflex mechanism may exist, and it may be activated by noxious stimuli from contralateral side. This reflex mechanism may initiate a series of events that lead to the injury of contralateral testis.