Laparoscopic Versus Open Upper Pole Heminephroureterectomy for the Treatment of Duplex Kidneys in Children

Abstract

Aim:

To evaluate the safety and feasibility of laparoscopic upper pole heminephroureterectomy (HNU) in pediatric patients with duplex kidneys in comparison with open surgery.

Patients and Methods:

From 2007 to 2011, 27 patients underwent HNU. A dimercaptosuccinic acid (DMSA) isotope scan revealed hypofunctioning of ipsilateral moieties in all cases. The patients were divided randomly into laparoscopic HNU (LHNU) and open surgery HNU (OHNU) groups. LHNU was performed by the transperitoneal approach in 10 girls and 5 boys with a mean age of 33 months (range, 9–108 months). All procedures were performed using three or four ports. Open surgery was performed in 10 girls and 2 boys with a mean age of 29 months (range, 7–174 months) by the retroperitoneal approach in all cases. Follow-up included ultrasound and DMSA.

Results:

Mean operative time in the LHNU and OHNU groups was 148 minutes (range, 100–220 minutes; 95% confidence interval [CI] 129–167 minutes) and 124 minutes (range, 100–150 minutes; 95% CI 115–133 minutes), respectively. In the LHNU and OHNU groups, mean analgesic requirement was 2.8 days (range, 2–4 days; 95% CI 2.4–3.2 days) and 3.7 days (range, 3–5 days; 95% CI 3.3–4.1 days), and mean hospital stay was 4.0 days (range, 2–8 days; 95% CI 3.2–4.8 days) and 5.1 days (range, 3–8 days; 95% CI 4.3–5.9 days), respectively. No intraoperative or major postoperative complications occurred. No conversion to open surgery was necessary in the LHNU group. Statistical analysis showed no statistical significant difference (P>.05) in the operating time between groups, whereas differences in the mean hospital stay (P=.048) and analgesic requirements (P=.005) were significant. The function of the remnant pole was preserved in all patients. Follow-up ultrasound showed asymptomatic cystic structures in 1 patient.

Conclusions:

The laparoscopic upper pole HNU is a safe and feasible procedure, even in infants. It is associated with minimal morbidity, and the operative time is acceptable and not significantly longer in comparison with the open approach. LHNU reduces analgesic requirements and hospital stay. In our opinion it should be the preferred option for HNU in children.

Introduction

Laparoscopy is gaining popularity in urological procedures in children. With the advent of technology the scope of procedures capable of being completed using laparoscopy has significantly expanded. Following the first case of laparoscopic nephrectomy in an infant reported by Koyle et al.,¹ laparoscopic urological surgery in pediatric patients has made significant progress. Laparoscopic nephrectomy in pediatric patients is now considered to be a safe and feasible procedure even in small children.² Upper pole heminephrectomy is a treatment option when the poorly functioning renal moiety in the duplex kidney is associated with ureteral ectopia or ureterocele. Since the first report of pediatric laparoscopic heminephroureterectomy (LHNU) by Jordan and Winslow³ in 1993, the operation has been performed using either a transperitoneal or a retroperitoneal approach.^4–7 Some advantages of LHNU are an excellent visualization of the renal parenchyma and distal ureter, fast recovery, good cosmesis, and a shorter hospital stay.⁵

Robinson et al.⁸ first described the advantages of laparoscopic partial nephrectomy compared with the open technique in the pediatric population. Subsequent series have demonstrated adequate short-term results with LHNU in children.^9,10

Despite widespread use of LHNU very few reports have compared the laparoscopic with the open approach,¹¹ and the advantages of LHNU over open surgery have not yet been verified in young children and infants.^6,8 However, in those studies patients undergoing lower pole heminephroureterectomy (HNU) for vesicoureteral reflux were included, although a lower pole HNU is more technically challenging.

Therefore, we have performed a retrospective analysis of the safety and feasibility of upper pole LHNU in pediatric patients with duplex kidneys in comparison with upper pole open surgery HNU (OHNU) in terms of operative and convalescence parameters.

Patients and Methods

From December 2007 to December 2011, unilateral upper pole HNU was consecutively performed in 20 girls and 7 boys ranging in age from 7 months to 14 years old (mean age, 31 months) (Table 1). All patients underwent ultrasound, voiding cystourethrography, and dimercaptosuccinic acid (DMSA) studies. The criterion for HNU was a nonfunctioning moiety. DMSA isotope scan confirmed hypofunction of ipsilateral moieties in all cases. The most frequent indication for HNU was ectopic ureter and ureterocele. Patients were divided randomly into LHNU and OHNU groups. LHNU was performed in 10 girls and 5 boys with a mean age of 33 months (range, 9–108 months). Open surgery was performed in 10 girls and 2 boys with a mean age of 29 months (range, 7–174 months). Both groups were followed up with ultrasonography and DMSA. Demographic data, diagnosis, surgical procedure, surgical time, complications, analgesic requirements, and length of hospital stay were analyzed.

Table 1.

Demographics and Clinical Characteristics of Patients

	OHNU	LHNU
Mean (range) age (months)	29 (7–174)	33 (9–108)
Sex (male/female)	2/10	5/10
Chief diagnosis
Hydronephrosis	9	9
Incontinence	3	2
Urinary tract infection	2	4
Indication for surgery
Ectopic ureter	5	3
Ureterocele	7	8
Operative side (right/left)	6/6	6/9

LNHU, laparoscopic heminephroureterectomy; OHNU, open heminephroureterectomy.

Surgical techniques

With the patient under general anesthesia, a Foley catheter and a nasogastric tube were placed to decompress the bladder and stomach, respectively. Amoxicillin/clavulanic acid in a dose of 30 mg/kg was used as antibiotic prophylaxis.

OHNU

The patient was placed in the lateral decubitus position. A subcostal flank approach with an incision below the 12th rib was performed retroperitoneally to access the renal bed. The ureter draining the upper pole was identified, mobilized, and transected. Its proximal portion was used as a handle to alleviate the resection of the upper pole. The vessels of the nonfunctioning moiety were identified, separated, and ligated with awareness to preserve the main renal vessels supplying the lower pole. The parenchyma of the upper pole was dissected from the lower pole and cut using an electrocautery device. After hemostasis was achieved by electrocautery, the renal parenchyma was closed with interrupted 4-0 polyglactin 910 (Vicryl™; Ethicon, Somerville, NJ) sutures. In the case of an ureterocele, the distal ureter was dissected from the subcostal incision at the level of the iliac vessels, and a drain was left within the ureteral stump. In patients with reflux, the resection of the distal ureter was performed through a Gibson incision. The perirenal drain was inserted, and the incision was closed.

LHNU

LHNU was performed transperitoneally in all patients using three or four ports. Patients were positioned at the 45° lateral position. The surgeon worked facing the patient's abdomen. A 5- or 10-mm camera port was inserted in the umbilicus by means of a Hasson open technique. Pneumoperitoneum was established with carbon dioxide at a pressure of 8–12 mm Hg depending on the patient's weight. Two or three additional working 5-mm ports were placed under direct vision. The ports were arranged as follows: the first one subcostally and the second one at the lower iliac quadrant, and, for a right side operation, a subxiphoid port was added for liver retraction. The colon was reflected medially, and ureters were identified. After the main vessels to the lower renal segment were exposed, vessels to the upper pole were separated and ligated with clips or a LigaSure™ (Ethicon Endo-Surgery, Cincinnati, OH) device, depending on the surgeon's preference. The upper pole ureter was mobilized carefully and transected next to the ureteropelvic junction. Its proximal portion was used as a handle to identify and isolate the upper pole. The renal parenchyma was divided and resected using an electrocautery and bipolar tissue sealing device. Hemostasis of the renal edges was achieved by an electrocautery and argon beam coagulator. The distal ureter was dissected near the bladder. In the case of vesicoureteral reflux the ureteral stump was ligated; otherwise it was left open, and the drain was left within it. The specimen was retrieved through the extended umbilical port incision. The perirenal drain was inserted through a 5-mm port site, and the incisions were then closed.

Results

The intraoperative and postoperative data are shown in Table 2. Mean operative time was 148 minutes (range, 100–220 minutes; 95% confidence interval [CI] 129–167 minutes) for the LHNU group and 124 minutes (range, 100–150 minutes; 95% CI 115–133 minutes) for the OHNU group. There was no statistically significant difference (P>.05) in operating time between the two groups. No intraoperative or major postoperative complications occurred in either group. All patients in the LHNU group underwent successful laparoscopic surgery without conversion to an open procedure.

Table 2.

Surgical Outcomes

	OHNU	LHNU	P value
Operative time (minutes)	124 (100–150)	148 (100–220)	.52
Analgesic requirements (days)	3.7 (3–5)	2.8 (2–4)	.005
Return to regular diet (days)	2.3 (2–3)	2.2 (2–3)	.81
Hospital stay (days)	5.1 (3–8)	4.0 (2–8)	.048
Postoperative renal cysts	0%	6.7%	NS

Data are mean (range) values or percentages as indicated.

LNHU, laparoscopic heminephroureterectomy; NS, not significant; OHNU, open heminephroureterectomy.

Analgesic requirement was significantly different (P=.005), with LHNU patients requiring 2.8 days (range, 2–4 days; 95% CI 2.4–3.2 days), whereas OHNU patients needed 3.7 days (range, 3–5 days; 95% CI 3.3–4.1 days). Median hospital stay was 4.0 days (range, 2–8 days; 95% CI 3.2–4.8 days) for the LHNU group and 5.1 days (range, 3–8 days; 95% CI 4.3–5.9 days) for the OHNU group (P=.048).

The patients resumed a regular diet on the second or third postoperative day, and there was no significant difference between the LHNU and OHNU groups. No patient had significant blood loss or required transfusion.

Median follow-up was 28 months (range, 12–60 months). All patients underwent ultrasonography at 3 and 12 months postoperatively, and no significant abnormality was detected. Symptoms in all patients have resolved after surgery. One patient (6.7%) from the LHNU group has developed asymptomatic renal cysts. We did not observe renal atrophy or significant loss of function in the remaining moiety. The DMSA scan revealed that the function of the remnant pole was preserved in all patients.

Discussion

Upper pole heminephrectomy is indicated in pediatric patients when renal duplication is associated with ureteral ectopy or ureterocele and the upper moiety is nonfunctioning. The standard heminephrectomy technique involves the isolation of the hilar vessels and separation of the upper pole supply, which carries risk of injury to the lower pole vascular pedicle. The success of the upper pole HNU depends on the maximal preservation of lower pole function, which requires careful identification of the main hilar vessels to prevent inadvertent injury, minimal excision of the lower pole parenchyma, and protection of the lower pole ureter. The accidental ligation of the lower pole vessels might produce lower pole ischemia, hypertension, or even renal loss.¹² Despite the fact that LHNU in duplex kidneys is a complex procedure with an increased risk of bleeding, urine leak, and deterioration of the remaining renal moiety, it tends to replace open surgery.¹³

Obvious advantages of the laparoscopic approach include excellent visualization of anatomical structures, shorter hospital stay, and better cosmesis. Laparoscopic heminephrectomy offers also additional advantages over open surgery. First, in laparoscopic surgery, thanks to magnification and minimal traction of the remnant pole, the risk of vascular injury is minimized. Second, the entire ureterectomy can be performed laparoscopically, without additional incisions.

In our experience, the median operative time for the OHNU group was shorter than for the LHNU group (124 versus 148 minutes); however, this difference was not significant. In series presented by Castellan et al.⁷ and Gao et al.,¹⁴ the mean operative time of the laparoscopic procedure was 125 minutes (range, 80–170 minutes) and 143 minutes (range, 90–195 minutes), respectively. In the series comparing LHNU versus OHNU presented by Garcia-Aparicio et al.,¹⁵ the mean operative time was 152 minutes for the OHNU group and 182 minutes for the LHNU group. These data are similar to the results reported in our series.

The analgesic requirement in the LHNU group was shorter compared with the OHNU group. Other studies have reported similar results.^8,15 This finding indicates that children in the LHNU group might experience less pain and felt more comfortable after laparoscopic surgery. The mean hospital stay of the LHNU group was also shorter compared with the OHNU group. This finding confirmed the results of earlier studies.^11,13,16 One can speculate that a lower level of pain and earlier return to normal activity allow for faster discharge of patients operated on laparoscopically.

LHNU can be performed using either a retroperitoneal or transperitoneal approach. After our initial experience with both approaches, we prefer the transperitoneal approach, and all patients in the present series underwent transperitoneal LHNU. We agree that the transperitoneal approach has the advantage of a larger working space permitting safe exposure and dissection of the kidney as well as complete ureterectomy.^7,16

Several investigators have reported that renal surgery using the transperitoneal approach increases the risk of intraperitoneal organ injury and intestinal obstruction.^2,7 In our present study series enteral trauma or intestinal obstruction was not observed in any patient. The time to return to normal diet was similar in the LHNU and OHNU groups.

The most serious complication of HNU is the moiety loss. Review of comparable studies demonstrates rate of moiety loss to be between 0% and 9%.^6,17 There are many factors affecting postoperative renal function following LHNU. Younger patient age, high insufflation pressure, excessive traction on vessels, and occurrence of immediate postoperative complications reflecting the technical difficulty predispose to renal moiety loss.¹⁷ In our series in the follow-up period we did not observe a single renal moiety loss, and the function of the remnant pole was preserved in all patients. However, as delayed renal deterioration can occur slowly over time, long DMSA scanning follow-up and blood pressure measurement are recommended, especially in complicated cases.

Renal cyst formation following LHNU is caused by incomplete resection of the involved moiety and leaving a small amount of retained tissue at the cut surface. These cysts are clinically insignificant. Asymptomatic renal cyst formation at the cut of parenchymal edge was observed in 1 of our patients, so the rate of this finding was much lower than reported in other series (18%–37%).¹⁷

Conclusions

The laparoscopic upper pole HNU is a safe and feasible procedure, even in infants. It is associated with minimal morbidity, and operative time is acceptable. LHNU reduces analgesic requirements and hospital stay. In our opinion it should be the preferred option for HNU in children.

Footnotes

Disclosure Statement

No competing financial interests exist.

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