Pediatric patients with neurogenic bladders frequently require procedures to increase their bladder capacity and provide channels for long-term catheterization. Augmentation enterocystoplasty in combination with a Mitrofanoff appendicovesicostomy or a Yang-Monti continent channel have been classically performed using open techniques. The first report of a minimally invasive laparoscopic approach to such procedures was published in 1993. With the advent of robotic surgery and its comparatively shorter learning curve, seven available degrees of freedom, and ease of intracorporeal suturing, such procedures have been increasingly performed using this approach with multiple reports and case series published since 2004.
Indications and contraindications
Augmentation enterocystoplasty is indicated in pediatric patients with either neurogenic or nonneurogenic bladder dysfunction secondary to a small capacity or poorly compliant bladder when behavioral, pharmacologic, and less invasive approaches have failed. Such patients frequently exhibit varying degrees of poor bladder emptying and thus may require long-term catheterization. Accordingly, these patients may either concurrently or independently undergo creation of a Mitrofanoff channel, if they have an existing appendix, or a Yang-Monti channel, which requires an ileal loop harvest.
In addition to routine surgical contraindications (e.g., severe pulmonary compromise, poorly controlled coagulopathy, active infections, severe malnourishment), relative contraindications include history of inflammatory bowel disease, radiation to the abdomen/pelvis, and multiple prior abdominal/pelvic surgeries with resultant adhesion formation, precluding a robotic approach. Inability to perform self-catheterization is not a contraindication to creation of a catheterizable channel, provided the patient has appropriate long-term support from caregivers; however, being able to self-catheterize prior to creation of a channel is advised.
Patient preoperative evaluation and preparation
We routinely perform fluorourodynamics preoperatively to evaluate bladder capacity, compliance, and morphology. An upper tract evaluation may be performed, if clinically indicated, with an ultrasound and/or nuclear medicine scan. Similarly, evaluation for vesicoureteral reflux may be performed using a voiding cystourethrogram (if able to void or at time of urodynamics) or via positional instillation of contrast cystography at the time of the procedure.
Evaluation of preoperative hemoglobin, white blood cell count, blood urea nitrogen, and creatinine levels is routinely performed preoperatively. Urine cultures are obtained at the preoperative visit and treated with appropriate antibiotics, as per sensitivity results. Patients are placed on a clear liquid diet the day before. Bowel prep with oral magnesium citrate may be performed depending on the severity of preexisting constipation. Cefoxitin is administered within 1 hour of skin incision for prophylaxis. If a severe penicillin allergy exists, a combination of vancomycin, gentamicin, and metronidazole is administered instead.
The importance of patient and caregiver education in the preoperative setting cannot be overstated. Counseling and familiarity with intermittent catheterization are established preoperatively in order to improve postoperative compliance, minimizing complications. It is also important to complete a comprehensive abdominal exam to help with surgical planning and placement of the stoma. Careful consideration should be given to the placement when renal transplant is being considered, which is routinely placed in the right lower quadrant.
Operating room configuration and positioning
The operating room is configured so that all team members have excellent views of the surgical monitors and access to all required equipment ( Fig. 37.1 ).
When using the da Vinci Xi system (Intuitive Surgical, Sunnyvale, CA, USA), the patient is positioned supine to allow for side docking of the robot. We place our patients in slight Trendelenburg (20–30 degrees) to allow for cephalad mobilization of the bowels. Ensure that all bony prominences are well padded. A Foley catheter is placed under sterile technique to assist with bladder instillation and identification intraoperatively. A suprapubic tube can also be placed to help with postoperative bladder drainage and intermittent catheterization training. It is our preference to place an orogastric tube for the intraoperative period only.
Insert a Veress needle just cephalad to the umbilicus and confirm intraperitoneal position using the water drop test. Pneumoperitoneum is set at 12 mm Hg. An 8-mm robotic trocar is placed, and the peritoneum is inspected for any signs of injury, adhesions from prior surgeries, and presence of an appendix. Two 8-mm robotic trocars are placed 6–8 cm lateral to the camera, on each side of the camera port, a 12-mm assistant port in the right lower quadrant, and a further 8-mm port in the left lower quadrant along the mid-clavicular line. The 12-mm assistant port, placed in the right lower quadrant, may serve as the stoma site in certain cases ( Fig. 37.2 ). It is very important to ensure that the trocars are not in close proximity to bony prominences, maximizing robotic arm range of motion.
Procedure: Augmentation ileocystoplasty and mitrofanoff appendicovesicostomy ( )
Ileal loop harvest and bowel anastomosis
Attention is directed towards harvesting the ileal loop for the augmentation portion of the procedure. The cecum and ileum are mobilized, and a 20–25-cm segment of ileum is identified 15–20 cm proximal to the ileocecal valve. Ensure that this segment of ileum is well perfused with at least two vascular arcades ( Fig.37.3 A). Placement of 3-0 silk stay sutures is performed at the proximal, central, and distal ends of the ileal segment. This may be accomplished by placing straight Keith needles through the abdominal wall to further assist with traction. Ensure that the central portion of the bowel segment can be mobilized to the anterior portion of the bladder without significant tension.
Mesenteric windows are created using monopolar scissors with intervening vessels ligated with bipolar energy. The ileal loop is divided using 45-mm EndoWrist Stapler (Intuitive Surgical, Sunnyvale, CA, USA) loads fired at both the proximal and distal ends. A side-to-side functional end-to-end bowel anastomosis is performed next ( Fig. 37.3 B). The antimesenteric edges are reapproximated loosely using 4-0 silk suture. Enterotomies are then made at the corners, and 45-mm EndoWrist Stapler loads are used to create the side-to-side anastomosis. The residual enterotomy is closed with a 3-0 silk suture in a running fashion. The mesentery may be closed with 3-0 silk suture to prevent internal hernia formation.
Appendiceal segment harvest
The appendix is identified and the appendiceal mesentery is separated from that of the cecum, ensuring all blood supply to the appendix is preserved ( Fig. 37.4 ). Next, using a 30-mm staple load, the appendix is harvested, with care taken to avoid injuring the vascular supply. A small cecal cuff can be incorporated into the harvest if extra length is needed. Alternatively, a 4-0 absorbable synthetic suture may be preplaced in a purse-string fashion at the base of the appendix, and subsequently used to close the cecal defect after appendiceal isolation.