Giant hydronephrosis management in the Era of minimally invasive surgery: A case series

Highlights • We reported on the laparoscopic trans-peritoneal approach for giant hydronephrosis.• No major peri-operative complications were reported.• Pre-operative decompression using a nephrostomy tube facilitates the surgery.


Introduction
Giant hydronephrosis (GH) is a rare urological entity, described in the literature as more than 1 L of fluid contained in the renal collecting system [1]. Its presentation is usually vague, but it is most frequently associated with abdominal distention. The most common cause of the condition, described in the literature, is ureteropelvic junction obstruction (UPJO) [1]. A limited number of cases of adult GH has been reported. GH if not discovered and managed early can result in long term complications such as hypertension, renal failure, renal rupture, and loss of renal unit [2]. here we present our experience in the late presentation of adult Giant hydornephrosis. The work reported herein adheres to the PROCESS criteria [3].

Presentation of cases
After institutional ethical committee clearance was taken for the project. A retrospective review of all cases of nephrectomies performed between December 2017-December 2019 at our institute. Among them, four patients presented with massive hydronephrosis (GH). The main complaint of all four patients (two male, two female) was flank pain, with two patients experiencing more pain on the right side and the other two with more pain on the left side.   with costophrenic angle tenderness in two cases. Renal profiles were normal in all the cases. All patients underwent pre-operative sonography, CT scan ( Fig. 1), and nuclear renal scan which showed a renal split function of <15% in all cases, with preserved anatomy and functioning on the contralateral side. Two patients required gradual decompression by nephrostomy tube insertion pre-surgery in the affected kidney due to presence of urinary tract infection, both patients were observed for any signs of acute kidney injury and cardiopulmonary distress post drainage. The patients' characteristics are displayed in (Table 1). Surgery was performed laparoscopically using a transperitoneal approach (Fig. 2); patients were position in a 30 • flank-up position.
Pneumoperitoneum was achieved through the open Hasson technique. (Four ports were used: a 5-mm subcostal port in the anterior axillary line; a 10-mm camera port halfway between the subcostal port and the umbilicus, and a 12-mm port 2 cm supero-medial to the anterior iliac supine, which is used for instrumentation and the passage of sutures or staplers to secure and divide hilar vessels. In all cases, a suspension stitch in the renal pelvis, through the anterior abdominal wall, was used to assist retraction for better identification of the renal hilum. Upper and lower windows were achieved after releasing the adhesions present in all cases. The renal hilum was controlled en bloc using a 60-mm vacular endostapler loaded with 2.5-m titanium clips. In patient #4 (Table 1), laparoscopic surgery was converted to an open procedure due to lack of space and severe adhesions sur-rounding the kidney. A crossing vessel was observed in one patient intra-operatively. The mean operating time was 79.7 min (range: 65−95 min), estimated blood loss was 75 mL and the mean hospital stay was 4 days (range: 2-6 days). None of the patients required drains intra-operatively and there were no major peri-operative complications. Patients were discharge in a good health status with follow up in the clinic. follow up clinical examination showed no sign of hypertension in all cases. Renal Ultrasonography was unremarkable for all patients along with normal renal function test.

Discussion
The first case of GH was described in 1746. Since then, few cases have been described in the literature [1]. This condition is a rare urological entity, defined in the literature as more than 1 L of fluid or fluid amounting to at least 1.6% of one's body weight, contained in the collecting system. A radiological definition, first described by Crooks et al. [4], is the occupation of the hemi-abdomen by the kidney with a midline cross which is the height of five vertebral bodies [2]. GH is more commonly reported in children than in adults. GH may be congenital or acquired but is mostly congenital and commonly caused by UPJO. Less commonly, ureteral ectopia, a duplicated collecting system, and aberrant vasculature causing extrinsic compression of the UPJO may produce GH. Acquired causes include ureteral calculus, trauma, ischemia, carcinoma, and retroperitoneal fibrosis [5]. Our cases presented with progressive abdominal distention, and two of them were associated with uri- nary tract infection which required urgent decompression. The final diagnosis was UPJO for all the cases. The most common presentation of GH is abdominal distention followed by fever, flank pain, hematuria, acute abdominal pain and less commonly, recurrent urinary tract infections [2].
With the right kidney mostly affected, the mean amount of fluid drained immediately on nephrostomy tube placement was 3.5 ± 0.6 L in adults and 1.9 ± 0.4 L in children. This significant difference can be explained by the delayed presentation in adults, who have a higher capacity of the retroperitoneal space to accommodate excess fluid, compared to children [2]. Complications of GH include renal failure, hypertension and mechanical obstruction to the adjacent organs. One of the known complications post nephrostomy insertion, is acute renal injury and cardiopulmonary distress, where the latter may be due to rapid decompression of the hydronephrotic kidney, which may then lead to a change in the hemodynamic balance. This is known as paracentesis induced circulatory dysfunction. This usually occurs after draining large volumes. The theory behind this is that with large amounts of intra-abdominal fluid, filling of the right atrium tends to be incomplete; as fluid is drained, venous return to the right atrium increases with a resultant increase in cardiac output and splanchnic vasodilation, leading to a severe decrease in the mean arterial pressure [2]. Diagnosis is usually performed with ultrasound, CT, and MAG 3, and treatment will depend on the diagnostic findings. The decision between nephrectomy and kidney sparing therapy is critical, and most cases described in the literature are treated either by simple nephrectomy or renal sparing surgery. Some studies report the rate of nephrectomy as being up to 30% and others report a rate of up to 70% [4,6]. Most of the reported cases are managed by open nephrectomy and gradual decompression by nephrostomy tube [7]. The management of GH should be treated on a case-by-case basis depending on salvageability of the affected kidney and accessibility of kidney-sparing therapy.
We are aware about the limitations of our study mainly the sample number was small and the retrospective design.

Conclusion
The management of GH should be treated on a case-bycase basis depending on salvageability of the affected kidney and accessibility of kidney-sparing therapy. When nephrectomy is indicated in giant hydronephrosis, the laparoscopic transperitoneal approach is feasible, with pre-operative decompression by nephrostomy tube and the application of a suspension stitch to facilitate the surgery.

Declaration of Competing Interest
The authors report no declarations of interest.

Source of funding
This research did not receive any specific grant from funding agencies in the public.

Ethical approval
Preliminary ethical approval, to be received with reference number during this week.

Consent
Patients have given their consents for the study to be published. A copy of the written consent is available, at any time.
Tarek Alzahrani: paraphrasing. Abdulrahman Binjawhar: draft of the manuscript and review of the literature.
Abdullah Aldughiman: draft of the manuscript and review of the literature.

Provenance and peer review
Not commissioned, externally peer-reviewed.