If you don't remember your password, you can reset it by entering your email address and clicking the Reset Password button. You will then receive an email that contains a secure link for resetting your password
If the address matches a valid account an email will be sent to __email__ with instructions for resetting your password
Address correspondence to: Yunman Tang, M.D., Ph.D., Department of Pediatric surgery, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu 610072, China.
To summarize the experience of using robotic surgery to treat midline cysts (MLC) of the prostate in pediatric patients with hypospadias, and to introduce and evaluate the initial outcome of seminal passage reconstruction via robot-assisted laparoscopy during the removal of symptomatic MLCs.
Patients and Methods
We included a case series of 17 symptomatic MLCs with hypospadias. All patients received both genetic and fertility evaluation. MLCs were removed via robot-assisted laparoscopy and the seminal passage was reconstructed in 7 patients.
Results
Five patients were assessed as fertile as adults, while the other 12 were assessed as infertile. All 17 patients received robot-assisted laparoscopic surgery to remove MLCs, and 7 patients received reconstruction of the seminal passage. Patients were followed-up for 5-24 months; there were no serious adverse events except for 1 patient who experienced a single occurrence of epididymitis 7 months after reconstruction of the seminal passage. There were no significant cystic remnants in any of the patients upon ultrasonography and/or urethrography after surgery. Urethroscopy and vasography were performed in 2 patients after reconstruction; in both cases, unobstructed seminal passages were indicated.
Conclusion
Reconstruction of the seminal passage is practical when carried out by robot-assisted techniques. Initial results indicated that the reconstruction operations were able to restore patency in the seminal duct in some of the patients. Fertility is the goal of this technique, and long-term follow-up is needed.
In male children, midline cysts (MLCs) of the prostate urethra involve a series of rare midline cystic lesions located between the urinary bladder and the rectum. Prostatic utricle cysts (PUCs) and persistent Mullerian duct remnants (MDRs) are two of the most common conditions associated with MLCs. PUCs and MDRs are also commonly associated with disorders of sex development (DSD).
Most MLCs are occult and asymptomatic; the others are problematic and pose a dilemma for clinical management. When a problematic MLC is indicated for resection, they have traditionally been excised via an open approach or laparoscopically. However, this poses a threat to the seminal tract. Furthermore, a technique for constructing the seminal passage has yet to be reported. We hypothesized that re-implantation of the vas deferens to the posterior urethra at the same time, as resection of the MLCs would maintain the patency of the seminal passages. Here, we report a series of 17 patients with symptomatic MLCs who were managed by robotic assisted MLC removal. Moreover, in seven of these patients, we attempted to reconstruct the seminal passages.
PATIENTS AND METHODS
We enrolled 17 patients aged from 1 year to 11 years. Most patients underwent two or more unsuccessful hypospadias repairs prior to admission and had suffered from recurrent epididymitis and/or urinary tract infection for a long period of time. All patients underwent pelvic floor ultrasonography and voiding cystourethrography (VCUG). Retrovesical cysts were observed by ultrasonography and confirmed communication with the posterior urethra on VCUG (Fig. 1).
Figure 1The arrow shows a large cyst in the posterior urethra that communicated with the urethra on VCUG examination revealed prior to surgery (A). The cyst disappeared after surgery (B). VCUG, voiding cystourethrography. (Color version available online.)
All patients received detailed endocrine assessment and completed chromosome analysis prior to surgery. Genetic testing (DSD panel or whole exome sequencing) was performed on patients who were likely to have genetic variations. The demographic information and detailed assessment results are given in Table 1.
Table 1The detailed information and fertility potential evaluation results
Prior to surgery, patients with urinary tract infections were treated with antibiotics and prostate massage until the infection was cured. Patients with Frasier syndrome and persistent albuminuria were treated in the Pediatric Nephrology Department with glucocorticoids prior to surgery, albeit with little effect. Finally, they received an intravenous infusion of human albumin for three consecutive days prior to surgery.
A multi-disciplinary team, consisting of pediatricians, a pediatric surgeon, an endocrinologist, and a geneticist, were responsible for evaluating the fertility potential for all patients. An oncologist and a transplant physician were added to the team for discussions relating to 2 patients suffering from WT1 gene mutation. The patients’ guardians were invited to participate in the clinical decision-making process. For patients with fertility potential, the recommendation was to restore patency in case the seminal passage been cut during cyst resection surgery. For patients with lower fertility potential, we informed the guardians of the option to perform seminal passage reconstruction but did not recommend it. All of the guardians were fully informed of the potential risks and benefits of the surgical procedure and made their choice on their own terms.
Surgical Technique
First, the patient was placed in the lithotomy position. The urethra was examined by cystoscopy to identify the opening and lumen of the MLC. The cystoscope was then removed, and a Foley catheter was placed into the bladder.
The camera port was introduced supraumbilically and robotic ports were arranged in both lateral borders of the rectus muscles. In addition, a 5 mm assistant port was placed 5 cm above the middle point between the camera port and the right robotic port. In order to facilitate appropriate exposure, a trans-abdominal holding suture (a 3-0 suture on a straight needle) was placed by passing the needle through the anterior abdominal wall, through the bladder, and back out through the anterior abdominal wall.
Next, the bilateral vas deferens (VDs) and ureters were identified. The apex of the MLC was grasped after the pelvic peritoneum had been opened. The MLC was then freed from the bladder toward the pelvic floor until the summit with the urethra. A longitudinal incision was made on the anterior wall of the MLC distally to identify the summit and avoid urethral injury. The MLC was then resected proximal to the urethra and then we sutured the posterior urethra. The patency of the seminal passage was then reconstructed in those with fertility potential. To restore seminal passage patency, we adopted two different methods. In the first patient, the bilateral VDs were transected at the attachment on the apex of the MLC. For other patients, the apex of the MLC was transected at the level of convergence of the bilateral seminal vesicles to the MLC in order to preserve the continuity of the VDs and the seminal vesicles. The MLC was then removed by transection on the neck close to the urethra. In the first patient, a short stump of posterior MLC wall was preserved and the bilateral VDs were sutured on its inner surface in a horizontal manner with 7-0 absorbable sutures. The urethral opening was then covered with the posterior MLC wall flap (Fig. 2). In other patients, the apex of the MLC (the bilateral seminal vesicles with VDs) was anastomosed with the urethral opening in an end-to-side manner (Fig. 2). A drainage catheter was placed at the pelvis and removed after 5 days. Except for cases 1 and 16, the other 15 patients underwent urethral reconstruction, or other additional operations, in a simultaneous manner (Table 1). The urethral stent was removed after 14 days.
Figure 2Schematic diagram of two different reconstruction methods. Method 1: The cyst was removed and the VDs were sutured on the preserved posterior MLC wall's inner surface, urethral opening was then covered with the posterior MLC wall flap (D1, D2). Method 2: The apex of the MLC was anastomosed with the urethral opening in an end-to-side manner (C1, C2). MLC, midline cysts; VDs, vas deferens. (Color version available online.)
Following evaluation by a multi-disciplinary team, 5 patients were considered to have fertility potential; the remaining 12 patients were considered to have reduced fertility potential. The guardians of 7 patients requested seminal passage reconstruction surgery, including 2 patients who were considered to have reduced fertility potential. All 17 patients received robotic surgery for MLC resection. Reconstruction of the seminal passage following MLC removal succeeded in 7 patients (Supplementary Fig. 1). Five patients were diagnosed with PUC on pathological examination and the remaining 12 were diagnosed with MDR.
Sixteen patients were free of urinary symptoms, such as lower urinary tract symptoms, urinary infection, epididymitis, and dysuria, when assessed at follow-up after 5-24 months. One of the 7 patients who received reconstruction surgery developed epididymitis 7 months after surgery but was cured with conservative treatments. Ultrasound examination failed to find evidence of relapse in any of the patients 3 months after surgery. Four patients (who did not undergo seminal passage reconstruction) received VCUG 3 months after surgery; no significant cyst remnants were observed (Fig. 1). Two of the 7 cases of seminal passage reconstruction underwent urethroscopy examination during the second stage hypospadias repair and received retrograde urethrography 14 days after urethroplasty surgery. Urethroscopy and urethrography showed that the reconstructed seminal passages were unobstructed (Fig. 3).
Figure 3Postoperative follow-up indicated that the reconstructed seminal passages were unobstructed. The arrow shows the posterior urethral opening of the seminal passage under urethroscopy (E). The arrow shows the reconstructed seminal passages were found behind the bladder under transurethral vasography (F). (Color version available online.)
MLCs have been classified as retention cysts of the Müllerian duct, prostatic utricle, ejaculatory duct, seminal vesicle, and prostate, depending on the location, shape, and embryological origin.
Although PUCs and MDRs share many features in terms of their anatomy and clinical manifestations, and represent the majority of MLCs in the pediatric population, these structures are considered to be two separate diseases.
In patients with hypospadias or DSD, PUC's are believed to arise as a result of an insufficient testosterone supply to the development of the urogenital sinus other than the Müllerian duct. Individuals with hypospadias may not have sufficient testosterone to inhibit vaginal formation during early gestation (9 weeks) when the vagina would normally form, thus resulting in an enlarged utricle. MDR is believed to be the result of dysfunctional anti-Müllerian hormone, a hormone that normally plays a role in the regression of the Müllerian duct in males. Therefore, a PUC is a counterpart of the lower third of the vagina in female while an MDR is the upper two thirds of the vagina and the uterus.
A narrowing cervix, which is located at the end of the uterus, at the apex of the vagina, could be noted by cystoscopy. The presence of the cervix differentiates between PUCs and MDRs.
Although a number of factors can lead to male infertility, there is no doubt that MLCs are an important cause of male infertility. In a previous study, Lotti et al reported that MLCs are detectable in approximately 1 in 10 infertile men.
Their frequency and volume are also known to be higher in subjects with severe oligo- or azoospermia when compared with fertile men. A cyst volume larger than 0.117 mL may be related to severe oligo- or azoospermia.
Persistent Müllerian duct syndrome: lessons learned from managing a series of eight patients over a 10-year period and review of literature regarding malignant risk from the Müllerian remnants.
This evidence seems to suggest that intervention should be carried out in almost all cases of MLC. However, another study reported that almost 60% of adults with MDR or PUC did not experience any cyst-related symptoms or ejaculatory/fertility impairment; thus, the authors of this particular study recommended that investigation and/or treatment should only be carried out in symptomatic or infertile patients.
Most MDRs and PUCs are small and require no treatment in the pediatric population. However, in some rare conditions, MDRs or PUCs may become large enough to cause symptoms. Various clinical manifestations have been reported, including recurrent urinary tract infection, epididymitis, urinary retention, hematuria, and pseudo-incontinence. Although there is no consensus on the specific indications for surgical intervention in children with MDR or PUC, most scholars support the fact that intervention could be offered to symptomatic cases. We indicated PUC or MDR resection for patients with recurrent or persistent symptoms with failed conservative therapy. We also indicated seminal passage reconstruction for patients in which the seminal duct was inevitably cut during surgery and if informed consent was obtained from the guardians.
Several studies have focused on the resection of MDRs or PUCs in pediatric patients; a number of approaches have been attempted in such patients, including transvesical-transtrigonal, extra-vesical, perineal, and the posterior sagittal approach.
However, very few previous studies considered the maintenance of seminal passage patency. When the VDs enter into the enlarged MDRs or PUCs, they need to be cut off during resection surgery for MDRs or PUCs.
Therefore, removal of PUCs is likely to compromise the continuity of the seminal passage while excision of the MDRs will not.
In all of our cases, we found that the VDs entered the enlarged Cysts, even in the MDR cases. This might be the result of a huge cyst compressing the ejaculatory ducts, thus leading to communication with the cystic cavity, as described previously by Kato et al.
When the VDs are cut during MDR or PUC excision, it becomes very challenging to restore the community of the seminal passage. We tried and succeeded in 7 of our patients (5 PUC cases and 2 MDR cases), thus indicating that reconstruction of the seminal passage is practical with robot-assisted techniques. However, the restoration of continuity does not necessarily restore patency. So far, only limited evidence has been obtained with regards to the restoration of patency in 2 patients; long-term follow-up is now required.
Some PUC or MDR patients with hypospadias also have DSD and exhibit definite chromosomal or endocrine abnormalities. A significant number of these cases will be infertile as adults. For these patients, it appears that there is no need for seminal passage reconstruction, unless the patient or guardian insists. We emphasize that patients with MDR and PUC should evaluate their reproductive potential in adulthood prior to surgery, and that we should communicate with the patients or their guardians with regards to the need for seminal passage reconstruction due to the inevitability of the seminal passage being cut.
It has been suggested that seminal obstruction on one side might reduce the rate of spermatogenesis, thus indicating that unilateral vasectomy is not an ideal modality for the treatment of epididymitis with PUCs.
Once PUCs have been excised, anatomical reconstruction of the seminal passage appears to be a far superior option than other techniques.
Previously, the challenges associated with the surgical excision of MDRs or PUCs related mostly to the choice of surgical approach for such a deep structure and the fact that the seminal passage would be cut. Laparoscopic surgery provides a better approach and surgical field than open surgery, and has therefore been advocated by more and more authors as a superior modality for the management of PUCs and MDRs.
Robot-assisted removal of a large seminal vesicle cyst with ipsilateral renal agenesis associated with an ectopic ureter and a Müllerian cyst of the vas deferens.
Robotic assistance provides excellent visualization with three-dimensional (3D) vision and easy manipulation of the instruments, thus allowing precise dissection and reconstruction in a deep and narrow space within the pelvic floor. Our practice further testified the advantages of robot-assisted laparoscopy for surgery involving symptomatic PUCs and MDRs in that the reconstruction of the seminal passage is possible and practical. Reconstruction of the seminal passage is practical when applying robot-assisted technology. We primarily re-implanted bilateral VDs into the posterior urethra in the first patient accidentally because we found it to be feasible. Later, we considered that the preservation of the seminal vesicles together with intact VDs might achieve an anatomic reconstruction that was closer to the natural status; we attempted this and succeeded. The re-implanted or re-anastomosed seminal passage should be monitored with regards to reflux and obliteration. This surgical area closed to the urethral sphincter and autonomic nerves that are responsible for preserving urinary continence. Surgeons should pay attention to gentle operation because the robot system has no tactile feedback. In addition, heat injury caused by the thermal radiation of the light source and energy instruments is another concern that needs to be considered. We recommend intermittent cold normal saline flushing of the operating field during the operation. In the present study, a 5-15 month follow-up period passed uneventfully, although 1 patient developed epididymitis 7 months after surgery. Recurrent epididymitis, urethrography, and urethroscopy, confirmed that the operation had been able to restore the patency of the seminal passage in some of the patients. However, further long-term follow-up is mandatory. Fertility is the ultimate goal of this technique; consequently, it is important to follow-up all patients until adulthood.
Author contributions
Daorui Qin: concept and designed the study, drafting the article, robot surgery. Yu Mao: patients’ evaluation, robot surgery. Xuejun Wang: patients’ evaluation and data collection. Bo Yang: data collection and analysis. Yunman Tang: supervisor, concept and designed the study, robot surgery.
Data availability statements
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
Ethics approval and consent to participate
The Ethics Committee of our hospital approved the study.
Acknowledgment
The authors would like to extend their gratitude to Dr Hongji Yang, Dr Jie Li, Dr Hailan He, Dr Yurong Zou, Dr Xiaoshi Zhu for their help in the patients’ preoperational evaluation. The authors also would like to express their gratitude to EditSprings (https://www.editsprings.cn/) for the expert linguistic services provided.
Persistent Müllerian duct syndrome: lessons learned from managing a series of eight patients over a 10-year period and review of literature regarding malignant risk from the Müllerian remnants.
Robot-assisted removal of a large seminal vesicle cyst with ipsilateral renal agenesis associated with an ectopic ureter and a Müllerian cyst of the vas deferens.
Funding Support: This study was supported by clinical research and conversion fund of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital (2017LY09).
00068-1&id=gr1.jpg){kind=link}
00068-1&id=gr2.jpg){kind=link}
00068-1&id=gr3.jpg){kind=link}