The role of laparoscopy in children with groin problems

The role of laparoscopy in children with groin problems

Minimally invasive surgery is an important advance in the development of modern surgery. There is an increasing trend to use laparoscopic techniques in pediatric urological practice for complex and reconstructive procedures on small children. In this review article, we focus on its benefits in diagnosis and management of various groin problems in children.

Undescended testis

Undescended testis is the most common congenital genitourinary anomaly in boys and has a prevalence of 1% to 9% in full term and 15% to 30% in premature male infants (1,2). Of all the undescended testis, 10-20% testes are non-palpable (1).

Pediatric laparoscopy dates back to 1976 when it was used, for the first time, for non-palpable testis (3). Since then laparoscopy has become one of the standards for both diagnosis as well as for the treatment of non-palpable testis (4-6). Diagnostic laparoscopy is commonly used for the assessment of a non-palpable testis, with the accuracy of testicular localization greater than 95% (7,8). Ultrasound, the most common non-invasive test performed, neither reliably localizes non-palpable testes nor does it rule out an intra-abdominal testis (1,9). Also, it does not alter the type of surgical approach in these patients and only adds to the health care expenditure (1,9,10). Diagnostic laparoscopy, compared to any imaging modality, has been shown to be more sensitive and specific for diagnosis and is helpful in assessment of the quality of the testis (1,6,11-13). In addition, many studies have shown various advantages of laparoscopy over open approaches including accurate identification of the presence or absence, viability, location, and the anatomy of the non-palpable testis (14-16). Interestingly, laparoscopy has also been demonstrated to have a beneficial role in establishing or refuting the diagnosis of an absent testis in previously inconclusive open exploration for a non-palpable testis (14,16-18). Additionally, it has been recently shown to help in the diagnosis of contralateral patent processus vaginalis in these patients; the incidence of which is around 20% (19,20).

Technique

Access to the peritoneal cavity

Two commonly used techniques are either an open or closed approach. For either, the stomach and the bladder should be emptied to avoid injury upon entering the abdomen. In addition, because the carbon dioxide used for insufflation is irritating, the patient should be either paralyzed or deeply anesthetized.

The open technique theoretically decreases the risk of iatrogenic injuries to the intra-abdominal structures, as well as reduces the risk of extra-peritoneal insufflations in inexperienced hands. In the open technique, a semi-lunar supra-umbilical or an infra-umbilical incision is used and is carried down to the rectus fascia. After sharply incising this layer, the pre-peritoneal fat is spread to expose the peritoneum. The peritoneum is grasped and opened sharply, followed by the placement of the trocar between the obliterated umbilical arteries. The size of the trocar is dependent on the size of the patient and varies from 2-3-mm to 5-mm and generally a zero-degree lens is used in most centers for pelvic laparoscopy (21). We prefer to use a closed technique of a Veress needle through the umbilicus followed by the dilation of the tract using a step system to allow for placement of a 2-3-mm trocar through the umbilicus (19,22). Pneumoperitoneum is achieved with carbon dioxide at a flow rate of 1 L/min (depending on the size of the child) at a maximum pressure of 15 mmHg; the pelvis is evaluated using a 0° 2.8-mm lens.

Diagnostic laparoscopy

The midline pelvis is inspected for landmarks. Generally it is best to first identify the urinary bladder. Next, both obliterated umbilical arteries are identified. They run along the anterior abdominal wall, just lateral to the urinary bladder and serve an important anatomic land mark for identification of the internal ring, vas deferens, and ureter. The surgeon should next look laterally to locate the vas and vessels as they pass through the internal ring. The localization of these structures is best done on the contralateral normal side (in unilateral non-palpable testes) and can be confirmed by gentle traction on the testicle, during which the surgeon can see the cord structures slide beneath the peritoneum. Examining the contralateral normal side is useful for comparing normal anatomy, especially in the case of a vanishing testis, so that the thickness of the vessels can be compared directly. Additionally, it helps to identify a patent processus vaginalis on the contralateral normal side in a unilateral non-palpable testis (19,20). The testes can be classified into three groups according to their location detected during surgery: absent (vanishing testis syndrome), intra-abdominal, and inguinal (another frequently used term is canalicular).

Absent testis

The finding of blind-ending vessels is pathognomonic for an absent testis and when, bilateral, has been termed vanishing testis syndrome. It is most commonly explained as in-utero torsion or a similar compromising vascular event. The spermatic vessels may be either normal or hypoplastic proximally (best to compare with the contralateral vessels), but distally as the vessels approach the internal ring they are atretic (Figure 1). This finding is seen in 36% to 64% patients with unilateral non-palpable testis (23-26). Several authors have suggested that compensatory hypertrophy of contralateral descended testis (26) with testicular length exceeding 2 cm indicates a vanishing testis. However, in our experience, this is not often seen and it is rarely convincing enough to avoid laparoscopy (27). A vanishing testis can be an intra-abdominal or inguinal-scrotal event (28). In an inguinal/scrotal vanishing testis the vas and atretic spermatic vessels can be dissected to the atrophic testicular remnant. It is controversial whether to remove the remnant (as about 10% of specimens reveal some residual germ cells) (29) and similarly controversial, some authors have recommended orchiopexy of the contralateral normal testis due to the presence of bilateral risk of torsion (24). In some cases, although a blind-ending vas is seen, blind-ending vessels are not noted in the vicinity. In these cases, the laparoscopic exploration must be carried in a rostral direction, accomplished by reflecting the bowel from the lateral gutter. Because there can be complete separation of the vas and testis, the exploration must visualize the spermatic vessels to be considered complete (30). When the spermatic vessels and vas enter the internal ring, one must consider the presence of viable testicular elements within the caudad extent of descent to rule out the possibility of testicular remnants or testicular nubbin (31,32). Histological hallmarks of an atrophic testicular remnant include fibrosis, hemosiderin deposition and calcification (29,32). In these patients, some clinicians would suggest that no further exploration is required as only 10-13% tissues have identifiable testicular tissues (33,34) while others recommend removal of these remnants due to potential risk of future malignant transformation (31,32,35). Due to the absence of long term follow up studies there are limited data available. If they are to be removed, the testicular remnants usually can be easily dissected through a scrotal or very low inguinal incision (31). We routinely recommend removal of these remnants and fixation of the contralateral testis as the patient is already under anesthesia.

Figure 1 Absent testis with atrophic vessels as visualized by transabdominal laparoscopy.

Intra-abdominal testis

Intra-abdominal testes (Figure 2) are located inside the internal ring and considered either low (within 2 cm of the internal ring) or high (>2 cm from the internal ring) (36). Some authors have classified low intra-abdominal testis as lying between the internal ring and iliac vessels and high intra-abdominal testis as lying above the iliac vessels (37). The processus vaginalis is patent in most of the cases of low-lying testes and a long looping vas deferens can often be seen entering the internal ring. Elder in 1994 reported that an ipsilateral patent processus vaginalis is associated with 91% chance of finding a viable testis whereas if it was closed 97% had absent or vanished testis (25). However, since then, it has been clear that most high lying intra-abdominal testes are associated with a closed internal ring.

Figure 2 Right intraabdominal testis as visualized by transabdominal laparoscopy.

In some cases, no obvious testis or cord structures can be found following routine inspection. Sometimes the vessels are found medially deep in the pelvis with the testis lying alongside the bladder. If not, the exploration must be extended rostrally. The surgeon can reflect the colon by dividing along the line of Toldt and carrying the exploration to the level of the kidneys. In most instances, these maneuvers will allow discovery of the testis. In exceedingly rare circumstances, the testis has been found to be in perinephric, perihepatic location, or fused with spleen (38). Also a contralateral pelvic inspection should always be done to rule out ectopic testis (Figure 3) or remnant. These testes or testicular remnants can be dissociated from the vas/epididymis and vas/epididymal stump and may be mistaken for an absent testis. It is essential to search for the spermatic vessels vs. the vas deferens, as the testis may be lying proximate to the vessels and not necessarily proximate to the vas (30,32).

Figure 3 Right ectopic testis with right vas and vessels entering the left internal ring.

Inguinal or canalicular testis

The surgeon can encounter an open internal inguinal ring with spermatic vessels entering the ring. In this case, the testis (or remnant) must be in the groin (31,37). In the case of some testes, gentle inguinal pressure will pop the testicle back into the abdomen. In either circumstance, the best treatment in most cases is a groin exploration (25).

Complications

Diagnostic laparoscopy is the most accurate means of determining whether a testis is intra-abdominal and has been shown to be a safe procedure in experienced hands (39,40). In a study by Passerotti et al., overall, there was a 2% complication rate, with 1.6% related to the access. Use of the Veress needle had a higher percentage of injuries compared to the open technique however the difference was not statistically significant. Other complications included pre-peritoneal insufflation sufficient to necessitate conversion to an open procedure (0.7%), vessel injury (0.4%), small bowel injury (0.4%), bleeding requiring conversion to open (0.1%), bladder perforation (0.1%) and vas deferens injury (0.2%) (40). The incidence of port site hernia after pediatric urological laparoscopy has been reported to be around 3.2%, similar to the reported incidence in adults and it is more likely to occur in infants (39).

Operative laparoscopy: laparoscopic orchiopexy/orchiectomy in non-palpable testis

Laparoscopic orchiopexy is now being done by many urologists for the management of an intra-abdominal testis. The author (BAK) is credited with performing one of the first laparoscopic orchiopexies in 1991 (41). Since then multiple studies have been done to compare the success rate of laparoscopic orchiopexy to open orchiopexy. Some of the initial studies reported a significant high number of Fowler-Stephens repairs instead of standard orchiopexy, probably due to a lack of standards for assessment of the length of the internal spermatic vessel pedicle (42). The length of the spermatic vessels is usually the limiting factor in tension-free mobilization of an intra-abdominal testis. One of the principal benefits of laparoscopic orchiopexy is that it allows access to the entire course of the spermatic vessels. Along with the magnification seen with laparoscopic approaches, the laparoscopic approach should aid in dissection and preservation of the main and collateral blood supply (43). Despite this, there are differences in the results, with early series of single-stage Fowler-Stephens laparoscopic orchiopexy showing a significantly higher atrophy of the testis than the two-stage repair and open approaches. But when comparing the two staged Fowler-Stephens approach, the laparoscopic approach had greater success than previously reported for the open approaches (44,45) and patients with a history of prior surgery had a higher risk of developing testicular atrophy (46). A meta-analysis and more recent studies have concluded that laparoscopic orchiopexy has a higher success rate as compared to open orchiopexy and it is, if not the procedure of choice, an acceptable and highly successful approach to the non-palpable undescended testis (44,46).

In a patient with low lying intra-abdominal testis laparoscopic orchiopexy can be performed with a relative ease (41). After the diagnostic laparoscopy, as described above, if it has been determined to proceed with laparoscopic orchiopexy, two 3 mm ports can be placed under direct laparoscopic vision. In recent years, we have placed the accessory instruments by incision alone, without using ports, to save expense, improve cosmesis and to reduce the risk of port site hernias. In a bigger child the other two ports can be placed in the mid-clavicular line, usually opposing each other at the level of the umbilicus. In infants, the ports must be placed high and laterally so that there is adequate working room in the tiny abdomen. Recently some authors have reported laparoscopic orchiopexy using single-incision multiport technique, however, long-term follow-up is required to fully evaluate its benefits and limitations (47).

The initial dissection begins by taking down the gubernaculum or other distal attachments of the testis. This is done sharply inside or at the internal ring while being careful to not damage the vas deferens or epididymis, especially keeping in mind of the possibility of long looping vas and the collateral blood supply of the testis. The peritoneum is incised sharply at the level of the internal ring lateral to the spermatic vessels up to the abdominal sidewall/psoas muscle and carried towards the origin of the vessels. Similarly the peritoneum is dissected medially from above downwards with direct visualization of the vas deferens. A large triangular window is left between the vessels and the vas. Preserving the peritoneum between the spermatic vessels and the vas is important for a two stage Stephen-Fowler orchiopexy, so as to preserve the collateral circulation to the testis. Even in a single stage procedure where the spermatic vessels are left intact, we attempt to preserve these collaterals. Further mobilization of the spermatic vessels, if required, can be done by dissecting the peritoneum away from the spermatic vessels and carrying the dissection of the spermatic vessels up to the level of the kidney. A subdartos pouch is created in a manner described for open orchiopexy (47). Delivery of the testis to the scrotum can be done by passing a curved hemostat (or large laparoscopic port) from the subdartos pouch over the symphysis pubis into the peritoneal cavity. This should be done, under direct vision, medial to the obliterated umbilical artery in order to shorten the distance to the scrotum (a version of the Prentiss maneuver). As in all orchiopexies, it is important to avoid excess tension on the spermatic cord but merely placing the testis in the scrotum allows for easier higher dissection of the vessels if needed. The testis is then placed within the dartos pouch. Before port removal, bleeding should be assessed laparoscopically, under low intra-abdominal pressure by releasing the pneumo-peritoneum. The fascia is closed with absorbable sutures in all port sites.

In the case of a high lying intra-abdominal testis the length of spermatic vessels is usually the limiting factor. In these patients a Fowler-Stephens orchiopexy is often the best option. The Fowler-Stephens procedure can be either a single-stage orchiopexy with division of the spermatic vessels (48) or a staged orchiopexy with division of the vessels at the first stage and testicle left in situ, followed by the second stage in 6 months (49). There are no absolute criteria for when division of spermatic vessels needs to be performed. It is easier to bring down testes in younger, smaller patients, but even in infants, a testis more than 2-3 cm away from the internal ring often requires either two stages or a division of the spermatic vessels (50,51). In a study by Koff et al. in 1996 there was no advantage of a two staged vs. a single stage Fowler-Stephens orchiopexy (52). However, in a recent meta-analysis it was shown that the two-staged Fowler-Stephens orchiopexy appears to carry a slightly higher rate of success than the single stage approach (85% versus 80% respectively) (53). During stage one, the spermatic vessels are cauterized or clipped, in situ, 2 to 3 cm superior to the intra-abdominal testis (51). The second stage of the orchiopexy is usually completed 3-6 months later. It can be performed in either open or in a laparoscopic fashion (54). In a laparoscopic technique, access to peritoneal cavity is obtained in a standard manner as described above. The same wide triangular peritoneal pedicle between the spermatic vessels and the vas is preserved. Dissection is restricted to the area medial to the vas and lateral to the vessels. Any gubernacular remnant is divided at the internal ring, and then the entire flap is dissected medial to the umbilical ligament care being taken to be at least 1 cm from the vas deferens. At this point the testis remains vascularized based on the peritoneal flap which is in turn based on the vas deferens. The testis is mobilized on this wide triangular peritoneum while carefully preserving the vasal artery and any collateral vasculature and placed in the subdartos pouch in a method described above (54).

Laparoscopic orchiectomy

Laparoscopic orchiectomy is done if the intra-abdominal testis is atrophic or hypoplastic. The vas can be clipped or divided with electrocautery, followed by ligation of the spermatic vessels and any gubernacular attachments. In most cases, testis being removed is small and can be delivered outside abdomen through a stretched 3 or 5-mm port (30).

Complications of laparoscopic orchiopexy

Results of open vs. laparoscopic orchiopexy procedures (primary or staged) are fairly comparable. However, laparoscopy has significantly less morbidity (37). Immediate complications of laparoscopic orchiopexy include mild ileus (41), ilioinguinal nerve injury and testicular torsion (55). Long term complications, as in the open procedure, can be testicular retraction (37) and testicular atrophy (36,37,54). Devascularization with atrophy of the testis can result from over-skeletonization of the cord, from overzealous use of electrocautery, from torsion of the spermatic vessels during passage of the testis into the scrotum, or as a result of ligation and division of the spermatic vessels during Fowler-Stephens orchiopexy (36,37,54). A long looping vas, though theoretically a benefit, has been reported to be associated with higher chances of testicular atrophy after laparoscopic orchiopexy (56).

Contralateral patent processus vaginalis

An additional benefit of diagnostic laparoscopy in unilateral non-palpable testis, has been in the diagnosis of contralateral patent processus vaginalis (Figures 4,5), the incidence of which has been around 10-20% (19,20,57). This rate is substantial and may pose a risk of developing a clinically significant inguinal hernia in the future. If a significant contralateral patent processus is found, this can be repaired easily at the same time of orchiopexy.

Figure 4 Closed right (contralateral) internal ring as visualized by transabdominal laparoscopy in unilateral left nonpalpable testis.

Figure 5 Open right (contralateral) ring as visualized by transabdominal laparoscopy in unilateral right nonpalpable testis.

Although some authors have used a laparoscopic approach in the management of palpable testis (58,59), inguinal approaches have been the standard practice for palpable testes (60). However, the real benefit of laparoscopy, in these patients, is in the diagnosis of contralateral patent processus vaginalis. The rate of a contralateral patent processus vaginalis has been as high as 34% in those with an ipsilateral hernia sac. After considering age, side, prematurity, location, and volume of the undescended testis, boys with a testis distal to the external ring had three times higher odds of a patent contralateral processus vaginalis than those with testes lying within the inguinal canal (61). This is comparable to the patency rate of the contralateral processus vaginalis in patients undergoing repair of unilateral inguinal hernia, which ranges from 11-74% (62-68). Though the significance of this is unclear, it is likely associated with testicular ascent of previously descended or retractile testes.

The presence of contralateral patent processus vaginalis in children presenting with a unilateral palpable testis can be safely and effectively evaluated by CO₂ insufflation (Goldstein test) (69), trans-abdominal laparoscopy (70) or trans-inguinal laparoscopy (62,63,71) similar to as described for unilateral inguinal hernia repair. We prefer trans-inguinal approach. Orchiopexy is performed using an inguinal incision. After localization of the testis, a careful dissection of the ipsilateral hernia sac, if present, is done from the cord structures. The hernia sac is dissected sufficiently to allow full mobilization of the testis. For the initial few patients we used the CO₂ insufflation test which is a modification of the Goldstein test (69) to determine the presence or absence of a contralateral patent processus vaginalis. The test is performed by introducing an 8 Fr feeding tube through the ipsilateral hernia sac into the abdominal cavity and distending the peritoneal cavity with CO₂. The contra-lateral groin and the scrotum are then palpated for crepitance. The presence of crepitance constitutes a positive test result. Currently, we perform trans-inguinal laparoscopy involving both introduction of the 8Fr feeding tube and a 70° adult cystoscope lens. Carbon dioxide insufflation is accomplished at a flow rate of 1 L/min to a maximum pressure of 15 mmHg. The contralateral internal ring is visualized and inspected to determine patency (Figures 6,7). In cases where the patency is unclear, the contralateral inguinal canal and scrotum are palpated for evidence of crepitance and the internal ring is inspected for air bubbles after pressure on the contralateral inguinal area, a sign that CO₂ had entered the groin (Figure 8). A contralateral patent processus can be repaired either with an open inguinal approach or there are a number of laparoscopic approaches described. In the absence of long term follow up studies it is not possible to estimate the impact of finding contralateral patent processus vaginalis. Potential advantages of examining the contralateral groin and closing a patent processus include avoiding a second anesthetic, sparing the parents the anxiety associated with a second operation, and sparing the physician the embarrassment associated with the appearance of a second hernia at a later date (71). In addition, we believe that a contralateral patent processus is associated with a contralateral “ascended” testis. Alternatively, finding the contralateral patent internal ring may lead to overtreatment of these patients as the true incidence of clinical significant contralateral hernia in these patients is not known.

Figure 6 Open right (contralateral) ring as visualized by transinguinal laparoscopy in unilateral palpable undescended testis.

Figure 7 Closed right (contralateral) ring as visualized by transinguinal laparoscopy in a left palpable undescended testis.

Figure 8 Air bubbles at the contralateral internal ring as visualized by transinguinal laparoscopy after insufflation and palpation of the contralateral groin.

Inguinal hernia

The basic principle of open inguinal hernia repair in pediatric patients is the ligation of the patent processus vaginalis and this is considered the gold standard for pediatric inguinal hernia repair (72-74). With the advent of the laparoscopic era, the trend began to move toward the application of laparoscopic techniques for pediatric hernia repair. In laparoscopic hernia repair, after the identification of patent internal ring, the overlying peritoneum is closed with a laparoscopic purse-string suture (75). The reported recurrence rate for pediatric laparoscopic inguinal hernia repair was approximately 4.4% (76,77) while the recurrence rate for open hernia repair has historically ranged from 0.3% to 2.5% (73,78,79). In order to improve these results, modifications and technical refinements of laparoscopic repair have been proposed, including placement of the stitch medial to the inferior epigastric artery (80) and the use of special needles or non-absorbable sutures (81). In addition, there are some very innovative techniques including a completely extraperitoneal laparoscopic repair (73) and laparoscopic hernia repair by the hook method (82) both of which have claimed a very low rate of recurrence in short follow up. Some studies have also reported that laparoscopic hernia repair in pediatric population leads to less pain, quicker recovery and better wound cosmesis. There is also the potential side benefit of simultaneous detection and repair of contralateral patent processus vaginalis (75,83,84). However the very low morbidity of open pediatric inguinal hernia repair with its proven long-term efficacy and low rate of damage to the vas, suggests that long term follow up studies are needed before laparoscopic hernia repair will replace the open inguinal hernia repair in pediatric patients (75,84).

Contralateral patent processus vaginalis

Although there is insufficient evidence to recommend the use of laparoscopic inguinal repair over open hernia repair in pediatric patients, the role of diagnostic laparoscopy for detection of contralateral patent processus vaginalis in patients with unilateral inguinal should not be underestimated (85-88). A meta-analysis reported that diagnostic laparoscopy is 99.4% sensitive and 99.5% specific in identifying the presence of a contralateral patent processus vaginalis (89). The reported patency rate of a contralateral patent processus vaginalis in patients with unilateral inguinal hernia has ranges widely from 11-74% amongst different studies (62-68,90). Whether the contralateral groin should be examined is a matter of debate with the authors of many publications taking sides in this debate. The opponents of routine contralateral groin exploration argue that it may lead to overtreatment of patients, as the true incidence of clinically significant contralateral hernia is only 5-29% (91-94) hence they argue that the repair of a contralateral processus vaginalis should not be performed (95-97). On the other hand, other authors have recommended the routine inspection as well as repair of contralateral patent processus vaginalis, as it is safe, reproducible, technically easy (20,86,98) and cost effective (99). Also, there are the advantages of avoidance of a second anesthetic, sparing the parents of the anxiety associated with a second operation, and sparing the physician the embarrassment associated with the appearance of a second hernia at a later date (71). For these above mentioned reasons we routinely inspect and repair contralateral patent processus vaginalis.

The presence of a contralateral patent processus vaginalis in children with unilateral inguinal hernia can be safely and effectively evaluated by CO₂ insufflation (Goldstein test) (69), transabdominal laparoscopy (70) or transinguinal laparoscopy (62,63,71). We prefer transinguinal laparoscopic approach in our center as described above in section of palpable testis.

Acknowledgements

None.

Footnote

Conflicts of Interest: The authors have no conflicts of interest to declare.

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