Robot-assisted laparoscopic bladder diverticulectomy in a seven-year-old child: Case report and points of technique.

Congenital bladder diverticulum is an uncommon anomaly of the bladder. Patients can present with urinary infection, heamaturia, and/or urinary obstruction. We report the case of a seven-year-old boy who presented with painful micturition and terminal haematuria due to a congenital bladder diverticulum. Robot-assisted laparoscopic diverticulectomy was performed. The patient had an uneventful recovery. We describe the points of technique pertinent to the procedure.

INTRODUCTION

Bladder diverticulum is an uncommon abnormality in children usually found in cystogram. A bladder diverticulum represents a herniation of the bladder mucosa between fibers of the detrusor muscle, resulting in an out pouching into the perivesical space. The exact etiology of congenital bladder diverticula is not known but is thought to represent an intrinsic weakness in the muscle wall of the bladder. They are most commonly seen adjacent to the ureteral orifice. Classification of bladder diverticula in children can be based on their etiology: (i) those associated with bladder outlet obstruction, (ii) those occurring after bladder surgery, (iii) those associated with specific syndromes, such as prune belly syndrome, and Ehlers–Danlos syndrome and (iv) primary, congenital, or idiopathic diverticula.[1]

The standard treatment of congenital bladder diverticulum is open surgical excision. Though laparoscopic diverticulectomy has been described in children, this procedure is technically difficult owing to the intra-corporeal suturing required to close the bladder after diverticulum excision.[2] We report a robot-assisted laparoscopic bladder diverticulectomy in a child and describe some pertinent points of technique.

CASE REPORT

A seven-year-old male child was brought to us with complaints of lower abdominal pain while voiding for one year and one episode of terminal haematuria six months back. He did not have any difficulty in micturition or constipation. Physical examination was normal. Ultrasonogram revealed a bladder diverticulum arising from left posterolateral wall. Micturiting cystourethrogram (MCUG) confirmed the large bladder diverticulum and showed no abnormality in urethra or vesicoureteric reflux [Figure 1a].

Figure 1

(a) Micturiting cystourethrogram showing a large bladder diverticulum arising from the left posterolateral wall of the bladder and smooth bladder wall. (b) Cystoscopic view of the opening of diverticulum superolateral to the left ureteric orifice. (c) Contrast study revealing the relationship of left ureter to the diverticulum

Initially, cystoscopy was performed and a double J stent was placed in the left ureter for intra-operative identification [Figures 1b and c]. A 12 Fr Foley catheter was placed over a guide wire inside the diverticulum to help in later identification and dissection of the diverticulum. A 14 Fr Malecot catheter was placed suprapubically to drain the bladder. The patient was placed in the lithotomy position with Trendelenburg tilt. A 12-mm robotic camera port was placed just superior to the umbilicus. Two pediatric 5-mm ports for robotic arms were placed inferolaterally about 8 cm from the midline. An additional 5-mm assistant port was placed lateral to the left port. The robot was docked and the movement of the inflated Foley catheter bulb was used to identify the site of diverticulum. The left ureter and vas deferens were dissected away from the diverticulum. Methylene blue was injected into the diverticulum to delineate its extent [Figure 2a].The diverticulum was dissected all around till the neck was reached and it was excised at the neck level [Figure 2b]. Detrusor muscle layer was closed in single layer using 3-0 vicryl [Figure 2c and d]. Reperitonealization was performed over a drain [Figure 2e]. The Foley catheter placed perurethrally was removed at the end of the procedure. The operating time was 65 minutes. The patient had an uneventful post-operative recovery. The suprapubic catheter was removed on fifth post-operative day. At 10 months follow-up the child was doing well with no urinary complaints [Figure 2f].

Figure 2

(a) Robot-assisted laparoscopic bladder diverticulectomy. Delineation of bladder diverticulum after methylene blue injection (black arrow – left vas deferens; white arrow – medial umbilical ligament). (b) Division at the level of neck of diverticulum (black arrow – neck of diverticulum; white arrow – left ureter). (c) Suturing the bladder (Part of diverticulum used for traction). (d) View after the repair of bladder defect. (e) Final appearance after peritonealization (black arrow – preserved left vas deferens). (f) Computed tomography urogram showing smooth bladder wall at the previous site of diverticulum and normal ureters (Note the clips which had been used intra-operatively).

DISCUSSION

Bladder diverticula are usually asymptomatic. Bladder diverticula are often diagnosed incidentally during radiologic evaluation for a urinary tract infection. Large bladder diverticula may predispose to urinary stasis, thus leading to urinary tract infection. It is usually diagnosed in MCUG and sometimes in bladder ultrasound or CT scan of the pelvis. It is usually not detected in an intravenous urogram since the bladder will overlie the diverticulum and the diverticulum may be filled with urine, which will dilute the contrast material. Larger diverticula can also be confused with other bladder lesions such as urachal cysts, bladder ears seen in very young children, bladder herniation, ectopic ureteral insertion at the bladder neck, bladder duplication, everting ureteroceles, and ureteral stump resulting from excision of the upper part of the ureter and kidney.[3]

The management of patients with congenital bladder diverticula depends on the presentation and symptoms. Evaluation and treatment of any bladder dysfunction should be considered prior to any attempts to treat the diverticulum surgically. Surgical treatment is indicated when there is persistent high-grade vesicoureteral reflux, and/or recurrent urinary tract infections, or documented obstruction of either the distal ureter or the bladder neck.

The key surgical principle is to reinforce the muscular hiatus of the bladder to prevent reformation of the bladder diverticulum. Extravesical approaches and laparoscopic techniques can be used in these cases. Laparoscopic approach to bladder diverticulectomy nearly doubles the procedure time as compared to open surgery,[4] whereas robotic approach has been shown to have operative time similar to open procedure.[5] With the three dimensional vision, motion scaling, tremor filtering and seven degrees of freedom the da Vinci Surgical System provides unmatched vision and precision to aid in fine dissection and perfect suturing required in reconstructive procedures. This is especially relevant in pediatric reconstructive procedures where the space is small and margin of error is less. When a concomitant ureteric re-implantation is required the benefits of using the robotic approach will be further apparent.

We emphasize a few points in our technique. The placement of a double J stent in the ureter is necessary when the diverticulum is close to the ureteric orifice, which is usually the case. This helps in the intra-operative identification of the ureter to prevent injury during dissection. Identification of the diverticulum from the outer surface of the bladder is difficult. We placed a Foley catheter into the diverticulum and inflated its bulb. This helped in moving the bulb of the catheter from outside for early identification of diverticulum. Further, keeping the diverticulum filled with methylene blue helped in maintaining the proper plane of dissection all around the diverticulum. Once the diverticulum is partially opened, part of the diverticulum can be used for traction to prevent the bladder defect from disappearing into the depths of the pelvis [Figure 2c]. The presence of Foley catheter between the edges of the bladder defect helps in placing the sutures in both sides properly [Figure 2c]. Using a suprapubic catheter rather than two perurethral catheters in a male child can reduce the risk of urethral stricture.

In conclusion, robot-assisted laparoscopic bladder diverticulectomy combines the lower morbidity associated with laparoscopic approach with the precision and ease of robotic approach in excision of diverticulum and reconstruction of bladder.