|Year : 2017 | Volume
| Issue : 2 | Page : 95-99
Laparoscopic pyeloplasty in children with ureteropelvic junction obstruction associated with crossing renal vessels
Rajendra B Nerli, Amey Pathade, Vishal Kadeli, K Shankar, Malikarjuna N Reddy
Department of Urology, KLES Kidney Foundation, KLES Dr. Prabhakar Kore Hospital and M.R.C, Belagavi, Karnataka, India
|Date of Web Publication||11-Oct-2017|
Rajendra B Nerli
Department of Urology, KLES Kidney Foundation, KLES Dr. Prabhakar Kore Hospital and M.R.C, Nehru Nagar, Belagavi - 590 010, Karnataka
Source of Support: None, Conflict of Interest: None
Introduction: Ureteropelvic junction obstruction (UPJO) is usually intrinsic; however, 15%–52% may be associated with crossing renal/lower pole vessels. Investigators have demonstrated that the presence of crossing vessels decreased the success rate of antegrade endopyelotomy. We prospectively reviewed our series of laparoscopic pyeloplasty in children and analyzed as to whether crossing vessels affected the morbidity and outcome. Methods: Children <18 years of age undergoing laparoscopic pyeloplasty for UPJO were prospectively included in the study. Pyeloplasty was performed anterior to the vessels, and the anastomosis was placed adequately distal to the crossing vessel. Children were followed up in the postoperative period for urinary tract infection, and a DTPA renogram was performed after 3 months in all. Results: Twenty (15.74%) children had crossing renal/lower pole vessels associated with UPJO. The mean age of these children was 11.0 ± years. The mean operating time was 96.15 ± 12.54 min as compared to 76.35 ± 8.16 min in children with UPJO alone. The mean blood loss was 31.50 ± 6.03 cc as compared to 29.56 ± 4.50 cc in children with UPJO alone. The mean postoperative hospital stay 51.50 h and 100% of the children showed improvement of renal function as well as drainage on the postoperative diuretic renogram done after 12 weeks of surgery. Conclusions: Crossing renal/lower polar is associated with UPJO in about 15% of children undergoing laparoscopic pyeloplasty. The presence of crossing vessels significantly prolonged operating time; however, the blood loss, postoperative hospital stay, and short-term outcomes were similar to children with UPJO alone.
Keywords: Crossing renal vessels, laparoscopic dismembered pyeloplasty, ureteropelvic junction obstruction
|How to cite this article:|
Nerli RB, Pathade A, Kadeli V, Shankar K, Reddy MN. Laparoscopic pyeloplasty in children with ureteropelvic junction obstruction associated with crossing renal vessels. J Sci Soc 2017;44:95-9
|How to cite this URL:|
Nerli RB, Pathade A, Kadeli V, Shankar K, Reddy MN. Laparoscopic pyeloplasty in children with ureteropelvic junction obstruction associated with crossing renal vessels. J Sci Soc [serial online] 2017 [cited 2020 Sep 18];44:95-9. Available from: http://www.jscisociety.com/text.asp?2017/44/2/95/216494
| Introduction|| |
The exact cause of ureteropelvic junction (UPJ) obstruction remains unknown despite investigation along a number of lines: embryologic, anatomic, functional, and histologic. Narrowing of the UPJO may be caused by an incomplete recanalization process in utero at the cephalad end of the developing ureter., Partial obstruction can result from an anomalous number or arrangement of smooth muscle cells within the upper ureteral wall causing peristaltic dysfunction. In the involved segment, the smooth muscle layer may be hypertrophied or virtually absent. Rarely, ureteral pleats or folds that contain all layers of the ureter can act as valves and cause obstruction.,
Crossing vessels compressing or distorting the UPJ may on occasions be the sole cause of ureteral outflow obstruction. More commonly, they coexist with other causes of UPJ obstruction. Aberrant vasculature arising from the renal vessels, aorta, vena cava, or iliac vessels that supply the lower pole of the kidney is frequently associated with the UPJO . Whether causative or coincidental, 25%–50% of UPJ obstructions are found to have this relationship., It is very important to note that these vessels pose a threat of hemorrhage during minimally invasive procedures designed to create renal pelvic funneling and relieve the obstruction at the UPJ. Moreover, these crossing vessels have also been shown to be a significant negative prognosticator.
Van Cangh and Nesa  demonstrated that the presence of crossing vessels decreased the success rate of antegrade endopyelotomy from 86% to 42%. With long-term follow-up (mean, 6.5 years), the success rate declined to 33% of those patients who presented initially with associated UPJ vessels and underwent this form of minimally invasive therapy. Laparoscopic pyeloplasty is being performed at many centers including ours and the success rates closely approach those of open pyeloplasty while offering the advantages of minimal invasiveness and quick recovery with minimal morbidity.,, Laparoscopic pyeloplasty can also be done easily on patients with UPJ obstruction for whom surgery with retrograde or percutaneous antegrade incisions has failed or on those who have an extremely dilated renal pelvis  and otherwise may not be candidates for endoscopic incisional techniques. Crossing vessels may also be easily avoided under magnified endoscopic imaging. However, a small intrarenal pelvis remains a relative contraindication. We prospectively assessed our series of laparoscopic pyeloplasty in cases of UPJO associated with crossing vessels in terms of operating time, bleeding, intraoperative and immediate postoperative complications, and short-term outcome.
| Methods|| |
Children <18 years of age undergoing laparoscopic pyeloplasty for UPJO were prospectively included in the study. The diagnosis of UPJ obstruction was firmly established based on history, physical examination, renal sonography, intravenous urography, computed tomography [Figure 1]a and [Figure 1]b, and scintigraphy. Exclusion criteria included the presence of active urinary tract infection and very poor renal function (split renal function <10%). The risks of the laparoscopic operation were fully explained to the parents of the children, which included postoperative infection, bleeding, failure of pyeloplasty, the need to convert to open surgery, damage to other viscera, and adhesion formation.
|Figure 1: (a and b) CT Urogram showing left-sided dilated pelvicalyceal system with a thin rim of renal parenchyma|
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The laparoscopic procedure was carried out under general endotracheal anesthesia. A Foley catheter and nasogastric tube were inserted. The patient was placed in a 45° lateral position and secured to the operating table. The first 5 mm endoscope port was inserted by open laparoscopy using a blunt Hasson cannula through the umbilical crease. The abdomen was inspected in detail so as to plan to insert the remaining two 3/5 mm instrument ports. Correct placement of these ports was critical to the ease of performing the anastomosis. Occasionally, an extra 5 mm port was placed for retraction purposes. The peritoneum overlying the exposed kidney was incised just lateral to and above the colonic flexure. The loose adventitia around the kidney was detached from the renal capsule. Once the correct plane was identified, the renal capsule was traced into the renal sinus until the renal pelvis was identified. The renal pelvis was dissected free from the medial side. The UPJ and the proximal ureter were identified. The adventitia around the proximal ureter and UPJ was cleared (pyelolysis). In children who had no crossing vessels, the ureter was dismembered with a small cuff of renal pelvis, leaving a 1.5–2 cm pyelotomy to reanastomose to the spatulated ureter [Figure 2]. The lateral wall of the ureter was opened longitudinally and spatulated for about 1.5–2 cm. The UPJ and proximal ureter attached at this point to the spatulated ureter was then excised. The ureteropelvic anastomosis was performed using a 6-zero polyglactin suture. The posterior anastomosis was completed first and a 3 Fr multi-length double pigtail catheter was inserted. The anterior anastomosis was then completed.
|Figure 2: (a) Laparoscopic image showing crossing lower polar vessel with dilated renal pelvis. (b) Lower polar vessel being dissected so as to free the ureteropelvic junction. (c) Ureteropelvic junction being dismembered from the renal pelvis. (d) Proximal ureter being anastomosed to the renal pelvis anterior to the crossing vessel|
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In a child with a crossing renal/lower polar vessels [Figure 2] and [Figure 3], the adventitia around the proximal ureter and UPJ was similarly cleared. A stay suture was placed on the ureter just distal to the anticipated future area of spatulation. A second suture was placed on the renal pelvis 2.5 cm above the level of UPJ, which allowed traction and maintenance of orientation. A subfascial dissection of the UPJ was carried out so as to separate the crossing vessels off the renal pelvis, UPJ, and proximal ureter. The proximal ureter was dismembered below the level of UPJ. The renal pelvis along with UPJ was brought anterior to the crossing vessels. A pyelotomy was done just distal to the stay suture on the renal pelvis. Excess of the renal pelvis along with the UPJ was excised. Pyeloplasty was performed anterior to the vessels, and the anastomosis was placed adequately distal to the crossing vessel. A 3 Fr multi-length double pigtail was similarly kept across the anastomosis.
|Figure 3: (a) Dissected ureteropelvic junction seen crossing the main renal vessel. (b) Proximal ureter being dismembered from the renal pelvis|
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The intraperitoneal drain was removed when the drainage was <5 ml/24 h. The urethral catheter was removed after 48 h. Oral feeds were started on the appearance of peristaltic sounds. Children were followed up in the postoperative period for urinary tract infection. A DTPA renogram was performed after 3 months in all.
| Results|| |
During the study period Jan 2010 to Dec 2015, 127 children (94 males and 33 females) undergoing laparoscopic pyeloplasty were prospectively included in the study. Only 20 (15.74%) of these children had crossing renal/lower pole vessels associated with UPJO. Obstruction to the UPJ was diagnosed based on intravenous program, ultrasonography, and diuretic radioisotope renogram in all. Crossing renal/lower pole vessels were suspected in 12 of the 20 children based on findings on routine ultrasonography and intravenous program. Renal angiography was done in only two of these cases.
The age, gender, duration of surgery, and operative blood loss of the children undergoing laparoscopic pyeloplasty was shown in [Table 1]. Crossing vessels were identified in 20 of these children (right side 11 and 9 on the left side). In three of these 20 (15.74%) children, the crossing vessels were the main renal vessels, whereas in the remaining 17 children, the crossing vessels were the lower polar vessels.
In none of the children, was it necessary to convert to open procedure. The peritoneal drain was removed after 36 h and the children were fed orally within 12 h of surgery. None of the children experienced postoperative fever or vomiting. The urethral catheter was removed 48 h after surgery.
All children were followed up, the double J stent was removed 6 weeks later, and a radioisotope renogram was done 12 weeks after surgery. The follow-up ranged from 18 to 72 months. Urine examination done at 12 weeks after surgery showed no active infection/bacteria in any of the children. There was reduction in the size of the renal collecting system as imaged on ultrasonography in all children. Diuretic renogram done at around 12 weeks showed improvement as well as good drainage in 95.32% (102) of children with UPJO alone in comparison with 100% (20) in children with associated crossing vessels. The remaining five children in the UPJO alone group had no deterioration of function and were asymptomatic. The split renal function as well as drainage showed improvement on renograms done later at 6 and 12 months after surgery in all these five children [Table 2].
| Discussion|| |
The renal pedicle classically consists of a single artery and a single vein that enter the kidney through the renal hilum . These structures branch from the aorta and inferior vena cava just below the superior mesenteric artery at the level of the second lumbar vertebra. The vein is anterior to the artery. The renal pelvis and ureter are located farther posterior to these vascular structures . An aberrant, accessory, or early-branching lower pole vessel is commonly associated with an extrinsic cause of UPJ obstruction. These vessels pass anteriorly to the UPJ or proximal ureter and contribute to mechanical obstruction. Reported incidences of UPJ obstruction secondary to vascular compression have varied between 15% and 52%. This a major cause of UPJ obstruction in adults. Whether the aberrant vessel causes the obstruction or is a covariable that exists along with intrinsic narrowing is unclear.
The evaluation of a hydronephrotic kidney commonly begins with either renal sonography, CT scan of the abdomen/pelvis, and/or an intravenous pyelogram. Dilation of the intrarenal collecting system does not necessarily mean obstruction or increased renal pelvic pressures. A radionuclide renal scan with an added diuretic phase (e.g., Mercaptoacetyltriglycine (MAG-3), diethylenetriamine-pentaacetic acid) is often necessary to determine the significance of renal pelvic dilation in terms of functional compromise. Surgical intervention is warranted when deterioration of renal function is evident and/or when the associated symptoms are progressive or severe. The goal of treatment is to improve renal drainage, maintain or improve renal function, and aid in the resolution of symptoms.
During the past two decades, urologists have been using minimally invasive imaging techniques such as helical CT angiography (HCTA) to visualize crossing vessels. In a series of 24 consecutive patients with symptomatic UPJ obstruction, 11 of 24 patients were found to have crossing vessels with HCTA visualization. Of those patients, 5 were treated with either laparoscopic or open pyeloplasty, which revealed 100% concordance with the HCTA findings.
Minimally invasive approaches in the repair of UPJ obstruction include endoscopic approaches such as endopyelotomy and pyeloplasties performed laparoscopically ,,, or with the assistance of the da Vinci robotic system  (Intuitive Surgical, Sunnyvale, CA). Laparoscopic pyeloplasty has gained in popularity, and several recent series have reported a success rate of >95%.,,, Apart from the usual advantages of minimal morbidity and shorter hospital stay, laparoscopic procedures have the advantage of a magnified view, which helps in better visualization of crossing vessels. Chen et al. reported their results from 57 patients, 50 with primary and 7 with secondary repairs after failing other minimally invasive forms of therapy. The mean operative time was 4.3 h, and the mean hospital stay was 3.3 days. The investigators reported that 30 (53%) of 57 patients had crossing vessels that were avoided.
Türk et al. reported their experience of 49 consecutive pyeloplasties that were all laparoscopically performed with an intracorporeally sutured anastomosis. Crossing vessels were noted in 57.1% of the patients (28/49). In all cases, the vessels were crossing anterior of the UPJ. The authors noted that not in every case, the vessels were the original reason for obstruction. They believe that a ballooned renal pelvis (because of intrinsic stricture) could drape over the anterior crossing vessels and result in angulations that could worsen the obstruction. Either way, the vessels are important and could be the reason for surgical complications or procedure failure. The authors advise that if anterior crossing vessels were present, the UPJ was to be dismembered and transposed ventral to the vascular structures. This maneuver would prevent a potential compressive impact of the vessels to the new anastomosis.
Our study clearly reveals that the presence of crossing renal/lower pole vessels was not associated with increased blood loss or any other complication during laparoscopic pyeloplasty as compared to children without crossing vessels. However, the presence of crossing vessels significantly (P< 0.0001) prolonged the operating time. This could be due to increased and careful dissection needed around the vessels. Postoperative complications and outcome of surgery were similar in both the groups.
Gundeti et al. reported an alternative technique of laparoscopic transposition of lower pole vessels (the vascular hitch) in pediatric patients. A select group of pediatric patients with moderate hydronephrosis with no calyceal dilatation and a well-preserved cortex, poor renal drainage with preserved split function, and lower pole crossing vessels were included for this procedure. Intraoperative criteria included a normal ureter and ureteropelvic junction with peristalsis. Nine boys and 11 girls aged 7–16 years (mean age 12.5) underwent laparoscopic transposition of crossing vessels, including 3 with da Vinci® robot assistance. The mean operative time was 90 min (range 47–140). The median hospital stay was 24 h. No ureteral stents or urethral catheters were placed intraoperatively. At a mean follow-up of 22 months (range 12–42), 19 of 20 patients (95%) had been successfully treated. One patient who had recurrent pain underwent successful laparoscopic pyeloplasty.
Nerli et al. reported on a 9-year-old child with UPJO associated with crossing lower pole vessels, who underwent laparoscopic transposition of the crossing vessels. Postoperatively, the child had persistent UPJO and was symptomatic. The child was reassessed and underwent standard laparoscopic transperitoneal Anderson–Hynes pyeloplasty. Repeat DTPA scan revealed improved drainage and the child became asymptomatic. The authors raise a word of caution that there could be a concurrent intrinsic factor along with crossing renal vessels, and at present, there are no imaging techniques which could identify these.
| Conclusions|| |
Crossing renal/lower pole vessels are observed in 15% of children undergoing laparoscopic pyeloplasty for UPJO. Crossing vessels significantly prolong operating times due to the careful dissection that is required. The blood loss and hospital stay are similar to those children without crossing vessels. The short-term outcome was good as assessed on radioisotope renogram in these children.
We would like to thank K.L.E.S Dr. Prabakar Kore Hospital and Medical Research Center, Belagavi, Karnataka, India.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2]