Laparoscopic and robot-assisted pyeloplasty

Introduction

The first laparoscopic pyeloplasty was performed in 1993. A subsequent series of the first 100 cases by the same surgeon demonstrated a success rate of 96%, which is comparable to open pyeloplasty outcomes. ^, Despite the equivalent outcomes while maintaining the associated perioperative advantages of minimally invasive surgery, laparoscopic pyeloplasty did not take off as expected, likely due to the steep learning curve required for mastering intracorporeal suturing. The development of robotic-assisted laparoscopic pyeloplasty allowed for improved time to mastering intracorporeal suturing, better wrist mobility, and ease of reconstructive techniques. An initial study found the robotic-assisted technique decreased intracorporeal suture time by nearly half compared with standard laparoscopic techniques. In this chapter, we discuss preoperative preparation, surgical technique, and postoperative management for laparoscopic and robot-assisted laparoscopic pyeloplasty, as well as touch upon new single-port techniques.

Indications and contraindications

The indication for laparoscopic or robot-assisted laparoscopic pyeloplasty is documented ureteropelvic junction obstruction (UPJO). Obstruction is often identified incidentally initially via abdominal imaging in the adult patient with a computed tomography (CT) scan or ultrasound finding of hydronephrosis. The presence of hydronephrosis, however, is not a clear indication requiring repair of obstruction. The presence of a delayed nephrogram on the nephrographic phase of the contrasted CT scan is increasingly indicative but not definitive. Obstruction is best defined by a nuclear renogram with a diuretic washout. This study provides drainage curves, uptake and excretion percentages, T ½ washout times, and the relative percentage of each renal unit’s function. Obstruction is typically defined as a T ½ greater than 20 minutes; however, consideration should be given to patients with a T ½ between 10 and 20 minutes if they are symptomatic (recurrent infections, worsening renal function, nephrolithiasis, flank pain, Dietl’s crisis, etc.).

Prior management of a UPJO does not preclude minimally invasive surgical options. Minimally invasive pyeloplasty can be performed after a failed endoscopic approach, failed open pyeloplasty, or failed prior laparoscopic or robotic pyeloplasty.

There are no absolute contraindications to laparoscopic/robotic pyeloplasty for ureteral obstruction except for the following surgical contraindications: uncorrected coagulopathy, active infection, and history of upper tract urothelial carcinoma without biopsy proving no recurrent disease. The relative contraindications include significant medical comorbidities, significant prior abdominal surgery, and significantly long strictures requiring other reconstructive techniques.

Preoperative evaluation and preparation

The initial evaluation includes a detailed history and physical exam with a focus on the presence of chronic/intermittent flank pain, infectious symptoms, history of recurrent infections, as well as feeling of or physical bulging of the abdomen or flank. Laboratory studies may vary based on preference, but at baseline, a complete blood count, basic metabolic panel, and urinalysis with urine culture should be obtained. Additionally, a nuclear renogram with diuretic imaging study is indicated to verify obstruction and assess split renal function. Longstanding obstruction may indicate a lower likelihood of improved renal unit function after intervention.

Cross-sectional imaging should be obtained for the evaluation of crossing vessels, atypical anatomy (duplicated system, horseshoe kidney, etc.), and coincident pathology such as renal stones, which may need to be removed at the time of reconstruction.

The decision to reconstruct versus simple nephrectomy should be based on multiple factors, including patient age, comorbidities, overall renal function, differential function, and patient preference. The presence of a poorly functioning kidney may preclude the utility of a ureteropelvic junction (UPJ) repair. A renal unit function of less than 15%–20% is often used as a cut-off when deciding whether to proceed with reconstruction as the surgical treatment may not yield any benefits.

Depending upon the timing of surgery, it may be beneficial to divert the collecting system prior to the procedure. Placement of a percutaneous nephrostomy tube or a ureteral stent will permit the kidney to drain while awaiting surgical intervention. Nephrostomy tubes may remain in place up to the time of surgery. If a ureteral stent is present, many experts prefer to remove it at least 2 weeks prior to surgery to minimize periureteral inflammation and edema.

Preoperatively, patients may be enrolled in an Enhanced Recovery After Surgery protocol. These protocols will vary between centers. Bowel preps are not typically employed but may be used to aid in visualization if preferred.

Preoperative setup/patient positioning

Upon induction of anesthesia, the patient is placed in a supine position. A second-generation cephalosporin should be used for preoperative antibiotics barring allergies. Compression stockings are used for deep vein thrombosis prophylaxis. For left-sided procedures, an orogastric, or less commonly nasogastric, tube is placed for gastric decompression. If not assessed prior, the patient is placed in the lithotomy position to perform a retrograde pyelogram to rule out any distal ureteral obstruction or assess for upper tract masses that may be causing the obstruction. A Foley catheter is then placed.

For the transperitoneal dismembered pyeloplasty, we place the patient in a 70-degree lateral decubitus position ( Fig. 23.1 ). Other surgeons prefer full flank or a more supine position. If a retroperitoneal approach is chosen, it is often optimal to proceed in the full-flank position with a slight break in the bed. Positioning aids vary between surgeons, and there is no consensus best approach. Beanbags, gel rolls, pillows, saline bags, or other positioning devices can be used interchangeably. The aim, however, is to provide a secure support system for the stability of the patient throughout the duration of procedure. The patient must be adequately padded and secured to the bed.

Arm position may also vary depending upon surgeon preference. The arm may be supported via pillows or a Krause arm support in a perpendicular shoulder position or may be secured to the patient’s ipsilateral flank ( Fig. 23.2 ). Care should be taken to keep all joints in a neutral position, thereby decreasing the risk of stretch or traction injuries. Then the patient is prepped and draped in sterile fashion.

Transperitoneal approach

Trocar placement

Insufflation can be obtained via any of the standard methods previously described in this book based on surgeon preference. Positioning and orientation of the ports will vary slightly based on the patient’s body habitus and abdominal scars and whether the laparoscopic or robotic approach is chosen. The initial trocar for both approaches typically starts at the level of the umbilicus. For the laparoscopic approach, this port will be at the umbilicus; however, for robot-assisted procedures, it will be lateral to the rectus. The trocar may be shifted up to a few centimeters cephalad for very tall/long torso individuals or laterally for obese patients.

For laparoscopic surgery, the three ports are typically placed along the midline. A 10- to 12-mm trocar is placed at the umbilicus and used for the camera. A 5-mm port is placed 6 to 8 cm cephalad to the umbilicus and a 10- to 12-mm trocar is placed 6 to 8 cm below the umbilical trocar. The midline positioning of the trocars allows for ergonomic intracorporeal suturing. On the right side, a subxiphoid port may be helpful for a liver retractor, though is rarely necessary given the location of the UPJ ( Fig. 23.3 ).

For robotic surgery, the trocar placement may vary depending upon which system is being used. The da Vinci Si system (Intuitive Surgical, Sunnyvale, CA, USA) can accommodate the same trocar placement as the laparoscopic approach ( Fig. 23.4 ). As usual with the Si system, the distance between ports must be optimized to minimize clashing. Standard recommendation is a minimum of 8 cm. The da Vinci Xi system is recommended to have all ports placed in a linear fashion along the lateral border of the rectus. There is an improved tolerance of working space for this device and the arms can therefore be placed closer together, with a minimum distance of 4 cm but preferably 6 to 8 cm. Assistant ports can be placed more medial to the robotic arms and should be triangulated between ports to prevent vertical “stacking” of the ports and optimizing the assistant’s access and mobility.