approximately 20% of undescended testes are truly impalpable , and laparoscopy is actually regarded as the gold standard for their localization ; none of the currently available imaging techniques ( ultrasound , computerized tomography , or magnetic resonance imaging ) has proven to be 100% reliable in predicting the presence or absence of a testis . in this respect , not only can laparoscopy be considered the most reliable tool to provide information on the location of the testis but also to confirm its absence . however , although normal and abnormal pelviscopic anatomy has been extensively described , some anatomical variants not corresponding to the actual anatomy have been reported over the years .
although these cases are seen rather infrequently , they might have significant implications both from a clinical and a legal point of view because they may lead to missing a gonad .
the records of all patients with impalpable testis ( it ) who underwent diagnostic laparoscopy from january 1993 to december 2000 were retrospectively reviewed . only testes that failed to be appreciated both during clinical examination and while the patient was anesthetized were considered truly impalpable .
no diagnostic tests were deemed necessary for localization before the procedure ; however , 83 patients had had a sonogram performed upon a pediatrician 's request , and 41 had undergone a human chorionic gonadotropin ( hcg ) test .
this was defined as a marked ( 2ds ) increase in testicular size as assessed by prader orchidometer .
testes with a marked increase in consistency according to 2 independent examiners , whether or not coupled with an increase in size , were also considered hypertrophied .
laparoscopy was performed in all instances with the hasson technique through the umbilicus with the exception of the first 11 cases in which a veress needle was used to obtain pneumoperitoneum .
all patients with laparoscopic evidence of spermatic vessels and normal contralateral gonads were operated upon .
surgery consisted in all instances of exploration of the inguinal region ; whenever present , testes were brought down .
vessels and gonads were defined as normal or hypotrophic , depending on the examiner 's personal experience .
the gonad was immediately visualized in 95 cases ( 43.7% ) ; in the remaining 124 cases , no gonad was seen while entering the abdomen with the laparoscope .
of the 95 cases in which the testis was immediately visualized , 76 were truly abdominal and 19 were  peeping . 
laparoscopic findings in the 124 cases in which a testis could not be demonstrated are shown in table 1 .
the patient with absent vas and vessels underwent surgical exploration for associated cystic dysplasia of the kidney ; a severely dysmorphic gonad , not identified on ultrasound , was found at the lower renal pole and was removed .
twelve patients had vasa , vessels , or both of these , exiting an open inguinal ring ( ir ) .
insertion of the lens into the processus vaginalis allowed visualization of gonads in 5 patients ( 4 were normal and 1 was hypotrophic ) .
, 6 normal testes in an ectopic position and 1 remnant were found . of the ectopic testes ,
3 were in a preperitoneal position , above the anterior iliac spine , and 3 had an interstitial location ( figures 1 and 2 ) .
in the 84 cases of vasa , vessels , or both exiting the ir , laparoscopy revealed a closed processus vaginalis .
spermatic cord vessels were deemed normal in 21 cases . on exploration , testicular atrophy was found in 18 patients , normal testes with preperitoneal ectopia in 2 , and a canalicular gonad in one .
a normal contralateral gonad was palpated in the scrotum , and in the other 33 , ch was found .
atrophy was found in 29 cases and a canalicular testis in one , which was brought down into the scrotum .
one testis was reported to be subsequently palpated by a primary care provider . regarding blind ending vas and vessels , in 7 patients only vas was present , and both structures were found in the remaining 20 .
seven patients were explored when positioning a testicular implant , and a scrotal nubbin was found and excised at the same time .
although the laparoscopic approach to it is still controversial , near general agreement exists that its diagnostic accuracy is far superior to that of any other modality both in localizing the testis and in confirming its absence . using this procedure
, we were able to visualize 95 gonads immediately and a further 5 by inserting the lens into a patent processus vaginalis . of interest , in 3 of these cases ,
although these findings can be easily explained by the different embryological origins of cord structures , they caution against laparoscopic closure of processus vaginalis , whether or not amenable to lens insertion . regarding the cases in which the testis was seen neither immediately nor after inspection of the processus vaginalis , surgical exploration revealed 11 additional testes .
as previously mentioned , in 1 case , the laparoscopic appearance was that of absent vas and vessels ; however , the association with multicystic dysplastic kidney allowed us to surgically explore the retroperitoneal region where the gonad was found at the lower renal pole and removed .
the management of such patients is still a matter of contention and literature reports are scant .
failure to locate vas and vessels laparoscopically has been reported to be associated with an intraabdominal testis in 2 of 3 cases , while in another report the patient suffered from praderwilli syndrome where excess adiposity in the abdomen made spermatic vessels nondemonstrable on laparoscopy .
our policy of surgically exploring all cases without clear evidence of a testis on laparoscopy led us to trace 10 gonads , 6 in which vas and vessels were exiting an open ir and 4 in which the ir was closed .
however , in a tertiary referral center , evaluation of ch can be a useful adjunct to the diagnosis of inguinal testicular atrophy ; in our experience , this was particularly helpful in cases with hypotrophic vessels and closed ir .
evaluation by experienced pediatric urologists as well as no previous hormone treatment are obvious prerequisites .
the problem of whether or not surgically exploring the inguinal region in it cases with cord structures in such anatomical situations has also received much attention in the literature .
some have questioned such a necessity especially in thin children ; other authors did not find any testicular tissue in spermatic cord structures removed during exploration .
on the contrary , plotzker et al advocate surgical exploration on the grounds of microscopic islands of viable tubular epithelium within the small nubbins of tissue residing in the inguinal canal . in our series , of the 10 testes discovered with vas and vessels exiting the ir , only 2 were inguinal while the remaining 8 were in a very unusual ectopic position
interestingly enough , in 4 cases , we found a preperitoneal ectopia , with the testis residing above the anterior iliac spine , a region which is infrequently palpated while evaluating a patient for it . in the other 4 cases , the testes were located in an interstitial position , which had rendered them rather flattened , thus easily missed on palpation also in thin boys . regarding the 2 other inguinal testes that would have been missed without exploration , our data are consistent with that of other authors series , of somewhere less than 5% of missed intraabdominal testes .
in addition , we believe that the finding of inguinal , blind ending vas and vessels is not , per se , an indication for surgery because risk of future malignancy is negligible and no cases have been reported so far .
more importantly , in our country , this problem is easily overcome by the patients request to have a testicular implant positioned in early adolescence , when inguinal exploration can be carried out with the same anesthetics . concerning blind ending vas and vessels , we found 7 cases of vas only and 20 cases with both structures .
a scrotal nubbin was present in the scrotum in the 7 patients in whom a testicular implant was positioned .
these data confirm the view of belman who considers this situation a scrotal event , with perinatal torsion occurring after descent but before fixation of tunica vaginalis .
eleven testes would have been missed in our series with laparoscopic findings consistent with absent / vanished testis .
therefore , we fully agree with ng who considers vasa and vessels blind ending above the ir as the only finding that would benefit from laparoscopy only . all other anatomical situations would ultimately require a surgical exploration in order to avoid significant clinical and legal complications at long - term follow - up .
it is carried out by well - trained laparoscopists with extensive knowledge of cryptorchidism and orchiopexy . 
whether or not open surgical procedures may in the future be completely replaced by laparoscopic orchiopexy is still to be determined .
 the diagnostic accuracy of laparoscopy for impalpable testis is well recognized . however , in some cases , laparoscopic findings may be misleading , and a viable gonad may be missed with significant medico - legal implications . from january 1993 to december 2000 , 202 patients with 219 impalpable testes were evaluated . in 95 cases , 
 the gonad was immediately visualized , and in 5 , the presence of a testis was documented by inserting the scope into the processus vaginalis . in the 119 remaining cases , 
 no gonad was seen while entering the abdomen with the laparoscope . 
 all patients with documented vas and vessels exiting the inguinal ring were surgically explored . 
 ten testes were found , 8 ectopic , with significant changes in shape and position , and 2 were canalicular . in the absence of hormone stimulation , no testes were found while exploring patients with cord structures coursing a closed inguinal ring and with contralateral hypertrophy . in 1 patient with absent vas and vessels , the testis was found at the lower renal pole while removing a dysplastic kidney . despite technical refinements and an increase in clinical practice , a small percentage of viable testes may be missed with laparoscopic findings consistent with absent / vanished inguinal testis . 
 therefore , inguinal exploration is mandatory in all these cases . 
INTRODUCTION
METHODS
RESULTS
DISCUSSION
CONCLUSION