Seminal Vesicle and Ejaculatory Duct Surgery



Seminal Vesicle and Ejaculatory Duct Surgery


BROOKE A. HARNISCH

JAY I. SANDLOW



SEMINAL VESICLE SURGERY

The seminal vesicles are paired male organs with no female homologue. They develop as a dorsolateral bulbous swelling of the distal mesonephric duct at approximately 12 fetal weeks. The seminal vesicle and the ampulla of the vas join posteriorly and superiorly to the prostate to form the ejaculatory duct at 13 weeks of life. The blood supply to the seminal vesicle is from the vesiculodeferential artery, a branch of the umbilical artery. Venous drainage is from the vesiculodeferential veins and the inferior vesical plexus. The seminal vesicles are innervated by the pelvic nerve and the hypogastric nerve. The hypogastric nerve sends both adrenergic and cholinergic fibers to the seminal vesicles. Lymphatic drainage is via the internal iliac nodes (1).

Primary pathology within the seminal vesicles is rare; secondary lesions are more common. In the past, insufficient imaging methods led to infrequent definition of either primary or secondary seminal vesicle pathology. The use of transrectal ultrasonography (TRUS), computerized tomography (CT), and magnetic resonance imaging (MRI) has improved diagnostic visibility and facilitated the diagnosis and treatment of seminal vesicle pathology. The necessity of surgical intervention is rare, but indications include congenital cysts with infection and/or obstruction causing infertility, ureteral ectopy into a seminal vesicle with resultant obstruction or dysplasia of the ipsilateral kidney, and primary tumors, either benign or malignant. Surgical access to the seminal vesicles is mostly via routes familiar to the urologic surgeon, but surgery on the seminal vesicles alone (without adjacent organ removal) is a unique challenge.



Alternative Therapy

There are relatively few alternatives to treatment of seminal vesicle masses, unless they are infected. Antibiotics may be utilized in this case. Many of the benign masses are asymptomatic and may be observed. Ejaculatory duct obstruction can also be observed if fertility is not an issue or if the couple desires sperm acquisition with in vitro fertilization.


Indications for Surgery

Treatments of conditions of the seminal vesicles alone are limited to (a) transperineal/transvesical aspiration of seminal vesicle cysts or abscesses, (b) transurethral unroofing of seminal vesicle cysts or abscesses, (c) laparoscopic or robotic dissection, and (d) open resection of one or both seminal vesicles.

Most procedures performed on the seminal vesicles are related to radical surgery for the treatment of urethral, prostate, bladder, or rectal cancer. Treatments specific to the seminal vesicle include transrectal aspiration of cysts or abscesses, transurethral unroofing of abscesses and obstructing cysts, and open resection for refractory infections, to excise an ectopic ureter or to remove benign or malignant masses.

If a solid lesion identified in the seminal vesicle shows no evidence of local spread and is benign on biopsy, treatment is dependent on symptoms. If the patient is asymptomatic, close follow-up consisting of repeat rectal examination and TRUS to determine subsequent growth of the tumor is reasonable. If the mass enlarges or if the patient has symptoms referable to the mass, simple seminal vesiculectomy is advisable. This may be accomplished through one of several routes described in the following text. If the mass is quite large and solid and demonstrates questionable margins, or if the biopsy shows malignant cells, the treatment of choice is quite different. Because fewer than 10 cases of primary tumors of the seminal vesicles have been treated at any one institution, it is difficult to define optimal treatment with any degree of certainty. Radical excision, which usually includes a cystoprostatectomy with pelvic lymphadenectomy, is the treatment of choice unless the tumor is extremely small. This recommendation is based on the extensive
nature of the majority of the cancers when detected. The excision may include the rectum (total pelvic exenteration) if it is thought to be invading the surrounding structures. Adjuvant therapy has no proven efficacy, although the only long-term survivors in the literature received radical surgery with subsequent pelvic radiation therapy or androgen deprivation therapy. No chemotherapeutic regimen is known to be efficacious (2,3,4).


Surgery

The most useful open surgical methods include transperineal, similar to radical perineal prostatectomy; transvesical, achieved by incising through the posterior bladder wall; paravesical; retrovesical; or transcoccygeal. Over the past decade, the laparoscopic or robotically assisted approaches to benign seminal vesicle lesions have been found to be remarkably direct and associated with much less postoperative morbidity than the open surgical approach (5). The choice of surgical approach, of course, depends partly on the characteristics of the lesion to be treated but probably more on the experience and expertise of the surgeon. For the most part, congenital lesions require an abdominal approach so that the ipsilateral kidney can be dealt with concomitantly, if necessary. Such lesions may be dealt with by laparoscopic or open surgical intervention. Benign lesions may be approached perineally; however, the risk of impotence is high even if a nerve-sparing approach is attempted. Larger benign tumors or cysts are best handled by an anterior abdominal approach, although a transcoccygeal method may be as useful. Again, the transperitoneal or retroperitoneal laparoscopic approach has great merit for such lesions. Patients with malignancy require radical extirpation, which commonly includes cystoprostatectomy, seminal vesiculectomy, and pelvic lymphadenectomy. This operation is no different from a routine procedure for bladder cancer and thus is not described here.


Preoperative Preparation

Preoperative preparation for laparoscopic, robotic, or open seminal vesicle surgery depends on the extent of the pathology and the planned incision. Transperineal, transcoccygeal, and transvesical approaches should be prefaced by a complete bowel preparation. Most surgeons use a mechanical preparation with GoLYTELY orally the evening before surgery, followed by the standard antibiotic bowel regimen. Some method to prevent phlebothrombosis in the legs, such as use of intermittent compression stockings during and immediately after surgery, is advisable.


Surgical Technique

A variety of surgical approaches to the seminal vesicles have been described, of which the most useful are the transvesical, transperineal, and laparoscopic.


Transvesical Approach

The transvesical approach to the seminal vesicle has been described by numerous authors (6). It is often used for large benign/cystic masses and cases where there is an ectopic ureter draining into the seminal vesicle. It allows for easy accessibility to the kidney, ureter, and bladder. A midline extraperitoneal suprapubic incision is made up to the umbilicus, and the rectus muscles are separated on the midline. The space of Retzius is opened by downward displacement of the transverse fascia on the pubis, and an Omni retractor is placed to expose the anterior bladder wall. Care is taken during this dissection not to injure the epigastric vessels on either side of the pubis. The bladder is opened longitudinally approximately 7 to 10 cm, ending 2 to 3 cm away from the bladder neck. Moist 4 × 8 sponges are placed on the bladder wall laterally and at the dome of the bladder, and specialized blades are placed to put the open bladder on stretch. Although it is not necessary, it is preferable to place long 8Fr feeding tubes in the ureters at this point to define the orifices and to help with identification of the subtrigonal ureters to prevent their injury later in the dissection. Using a Bovie cutting stylet, a vertical incision is made through the trigone on the posterior midline approximately 5 cm in length (Fig. 50.1A). Alternatively, a transverse incision just above the bladder neck can be used, but it is not preferred. The vertical incision is deepened through the bladder muscle, and the ampullae of the vas should be recognized directly beneath the bladder neck. They can be dissected by scissors down to their entrance into the prostate and then either ligated and divided or left intact, depending on the pathology, as described in the perineal approach. Just lateral to the ampullae on the prostate base, the seminal vesicles should be identified and the plane surrounding them entered easily unless there has been prior inflammatory disease (Fig. 50.1B). The seminal vesicles should be encircled and dissected completely free. Metal clips should be placed on the vascular pedicle and a 2-0 chromic tie on the distal end at the prostate. A clip is placed across the proximal end of the vas to prevent seminal vesicle contents from obscuring the field, and then the vesicle is transected and removed. If there is a moderate-sized cyst, the dissection is more involved but is usually made simple because the perivesical plane is usually more pronounced. The plane may be very difficult to establish if there was prior vesiculitis, and in this instance, the ureteral catheters are a welcome safeguard—care must be taken not to dissect completely through Denonvilliers fascia posteriorly and into the rectum. The posterior bladder incision is then closed with a running 2-0 absorbable suture in the muscle layer, followed by a running 4-0 absorbable suture in the mucosal layer. The ureteral stents and 4 × 8 sponges are removed, a 20Fr urethral catheter is placed, and the anterior bladder wall is closed similarly to the posterior wall. Suprapubic tube placement is an option but is not necessary. A suction drain is placed through a separate stab incision and positioned in the prevesical space away from the suture line. The urethral catheter is typically removed in 5 to 7 days. This approach is more prone to blood loss and ureteral injury than the perineal approach, but a rectal laceration is much less likely.


Transperineal Approach

The transperineal approach to seminal vesiculectomy is virtually identical to radical perineal prostatectomy, described in Chapter 32. An exaggerated dorsal lithotomy position is used to elevate the perineum so that it is parallel to the floor. An inverted U incision is made in the perineum and the central tendon is divided (Fig. 50.2A). An anterior retractor stretches the rectal sphincter superiorly, allowing visualization of the glistening anterior rectal fascia fibers. The rectourethralis is divided near the prostatic apex and a weighted speculum is placed, dropping the tented rectum. To adequately expose the seminal vesicle, the rectum should be dissected off the posterior surface of the prostate to a point higher than that needed for perineal prostatectomy. Denonvilliers fascia is then incised transversely or in the midline (if nerve-sparing) on the prostate near the base of the seminal vesicles.







FIGURE 50.1 The transvesical approach to the seminal vesicle. A: Vertical incision in the trigone to expose the retrovesical seminal vesicle. Inset, line of incision. B: Dissection of the vas ampullae (V) and seminal vesicles (S).

Seminal vesicle dissection is facilitated by posterior traction on the prostate provided by placement of a Lowsley retractor in the bladder. Medially, the ampullae and seminal vesicles are apparent after Denonvilliers fascia is incised (Fig. 50.2B). The ampullae can be spared for the excision of a simple seminal vesicle cyst or small tumor but may need to be resected in the setting of cancer or infection. After dissection of the seminal vesicle at the prostatic base, an absorbable tie of 2-0 suture is used to ligate the gland (see Fig. 50.2B). Before division of the seminal vesicle, a clip is placed on the cut end of the organ to minimize spillage. An Allis or Babcock clamp is then placed on the freed base of the seminal vesicle to ease the apical dissection. The vascular pedicle at
the apex of the gland is usually observed within 1 cm of the tip and is ligated with small metal clips, allowing gland removal. The wound is closed in layers as outlined for perineal prostatectomy. A Penrose drain is left in the area of dissection for 24 hours or until no drainage is noted. This approach is well tolerated, and patients are usually discharged within 24 to 48 hours of surgery.






FIGURE 50.2 The transperineal approach. A: Inverted U-shaped incision in the perineum with takedown of the central tendon. B: Exposure and ligation of the seminal vesicles after incising Denonvilliers fascia.


Paravesical and Retrovesical Approaches

The paravesical incision is used in children, when there is a large unilateral cyst that lies lateral to and above the bladder and when nephroureterectomy is required. A midline or Pfannenstiel extraperitoneal suprapubic incision is made. The bladder is finger-dissected away from the lateral pelvic sidewall on the affected side. The vas deferens is identified, placed on tension, and dissected down toward the base of the bladder. If the seminal vesicle mass is distended, it should be visible rather quickly as the vas comes close to the bladder posteriorly. Placing a catheter in the bladder and emptying it usually allows the plane between the bladder and the cyst to be readily identified. The plane is incised with scissors, and the seminal vesicle cyst is carefully dissected away sharply. When the tip of the cyst is clearly identified, a 1-0 chromic suture is placed into it to provide traction, making further dissection easier. As the dissection proceeds, it must be remembered that the ureter crosses the vas and must be identified to prevent its injury. In addition, the superior vesicle artery and perhaps the inferior vesicle artery may be sacrificed to gain access to the base of the seminal vesicle. This will cause no harm and should
be done without major concern. As the dissection proceeds, the bladder is progressively rolled over medially, and the mass is dissected away from the bladder laterally. The plane is easily maintained with sharp dissection. Any vessels feeding the seminal vesicles should be suture-ligated or metal-clipped. As the prostate is approached, caution must be used to stay directly on the mass so as not to injure the neurovascular bundle lying just lateral to the seminal vesicle. At the prostate base, the neck of the seminal vesicle is encircled and ligated with a 2-0 absorbable suture. A clamp is placed across just distal to the tie, and the seminal vesicle is severed. There may be no need to clip the vas. A suction drain is placed in the bed of the seminal vesicle and brought out through a separate stab incision. The wound is then closed in layers. Postoperative care is as previously described, except with this approach, the drain can be removed within 24 hours if there is no drainage, and the urethral catheter can be removed within 24 hours. The patient may be discharged within 2 to 3 days. Complications include ureteral injury and excessive blood loss. If the principles outlined earlier are followed, these are unlikely events.






FIGURE 50.3 The retrovesical approach. A: Midline infraumbilical incision (broken line). B: Incision of the posterior peritoneum over the rectum (R) in the cul-de-sac. B, bowel. C: Exposure of the vas ampulla (V) and seminal vesicle (S) behind the bladder. U, ureter.

The retrovesical approach should be considered in patients requiring bilateral excision of small seminal vesicle cysts or benign masses (7). A midline suprapubic incision is made into the peritoneal space (Fig. 50.3A). A catheter is placed, and the urine is evacuated. The reflection of the peritoneum over the rectum at the posterior bladder wall is incised transversely, with care taken not to incise into the rectum (Fig. 50.3B). The bladder is peeled back from the rectum progressively with sharp dissection until the ampullae of the vasa and the tips of the seminal vesicles come into view (Fig. 50.3C). The seminal vesicles are dissected down to the base of the prostate, much as described in the transvesical approach, and the neck of the seminal vesicle is ligated and divided bilaterally. The ampullae are usually not taken unless necessary. A suction drain is left in the area posterior to the bladder and brought out as before. Postoperative care is as per the description for a paravesical resection. Complications include rectal injury, bladder laceration, and hemorrhage. In this situation, a rectal injury would be within the peritoneum well above the levator ani muscles. After a two-layer closure as before, strong consideration should be given to placement of omentum over the closure between the bladder base and the rectum as well as to a temporary colostomy.






FIGURE 50.4 The transcoccygeal approach. A: The incision (broken line) is made over the coccyx and curved along the gluteal cleft. B: Denonvilliers fascia is incised deep to the rectum (R) to expose the prostate (P) and seminal vesicles (S). V, vas ampulla.


Transcoccygeal Approach

The transcoccygeal approach may not be familiar to most urologic surgeons and is unlikely to be a common choice owing to fear of rectal injury and impotence. In individuals for whom the perineal or supine position may be difficult to maintain, or who have had multiple suprapubic or perineal surgeries, the transcoccygeal approach may be very useful. The patient is placed on the table, ventral side down (prone), and in a relative jackknife position (8,9). The incision is made in an L shape from midway on the sacrum (10 cm from the tip of the coccyx) and angled at the tip of the coccyx down the gluteal cleft within 3 cm of the anus (Fig. 50.4A). The incision is carried down to the lateral side of the coccyx, which is dissected free from the underlying
rectum and eventually totally removed. The gluteus maximus muscle layers are moved aside, and the rectosigmoid is encountered and dissected carefully from the underside of the sacrum. With careful dissection, the lateral wall of the rectum on the side of the lesion is dissected medially from the levator ani muscle and surrounding tissue until the prostate is encountered. It is possible that the neurovascular bundle will be recognized from this approach. Once the prostate is palpated, dissection of the tissue directly superior to the base on the midline should reveal the ampulla of the vas and, lateral to it, the seminal vesicle (Fig. 50.4B). If difficulty dissecting the rectum away from the prostate is encountered, a finger in the anus via an O’Connor sheath will allow the correct plane to be determined. Dissection and removal of the seminal vesicles should follow the principles outlined previously. A Penrose drain should be left in the area, exiting through a separate stab incision at closure. The rectum should be carefully scrutinized for injury; if any injury is found, it is closed in two layers. The wound is closed in layers as well. Postoperative care does not differ from that previously described; similar to the perineal approach, the patient should have a rapid and easy recovery. The drain should be removed within 2 to 3 days if there is no drainage.

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Apr 24, 2020 | Posted by in UROLOGY | Comments Off on Seminal Vesicle and Ejaculatory Duct Surgery

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