Acute mechanical duodenal obstruction due to giant hydronephrosis: an unusual cause of acute abdomen

Abstract

Giant hydronephrosis (GH) is a rare clinical entity with about 600 cases and defined as the adult renal pelvis containing greater than 1 L of fluid, or at least 1.6% of the body weight or kidney occupying the hemiabdomen. The pelvic-ureteric junction (PUJ) obstruction is the most frequent cause of GH. We thus report a case of massive abdominal distension due to GH secondary to PUJ obstruction who presented with acute duodenal obstruction due to extrinsic compression and was managed with percutaneous nephrostomy followed by open nephrectomy.

Background

Giant hydronephrosis (GH) is a rare clinical entity with about 600 cases reported in the literature until now. A GH is defined as the adult renal pelvis containing greater than 1 L of fluid, or at least 1.6% of the body weight or kidney occupying the hemiabdomen. The pelvic-ureteric junction (PUJ) obstruction is the most frequent cause of GH. We thus report a case of GH secondary to PUJ obstruction who presented with acute mechanical duodenal obstruction and was managed with percutaneous nephrostomy followed by nephrectomy.

Case presentation

A 17-year-old boy presented to emergency room of our hospital with nausea and bilious vomiting for 3 days. He also suffered from intermittent right flank pain and gradually progressive right abdominal swelling for the last 1 year. There was no history of haematuria, lithuria, pyuria, recurrent urinary tract infections, fever and surgical interventions. On examination, the boy was of average build and nutrition with stable vital signs (PR 98/min, blood pressure 104/58 mm Hg). General physical examination revealed no abnormality. Neurological and cardiopulmonary examination was normal. On abdominal examination, diffuse abdominal distension was noted as shown in figure 1. It was soft, ill defined, non-tender and cystic in nature without hepatosplenomegaly.

Figure 1.

Clinical picture of abdomen showing diffuse abdominal distension.

Investigations

Blood serum chemistries revealed haemoglobin of 145 g/L with total leucocyte count of 12x10⁹/L. Renal function, serum sodium, serum potassium and liver function tests were normal. Urine analysis revealed 2–4 pus cells/high power field with absence of red cells and proteins. Urine culture was sterile after 48 hours of incubation. Ultrasonography of abdomen revealed distended bowel loops with gastric dilatation with normal bladder wall thickness with giant right hydronephrosis and non-dilated right ureter. On clinical examination and initial investigations, provisional diagnosis of acute mechanical duodenal obstruction due to giant right hydronephrosis secondary to right PUJ obstruction was made. The nasogastric decompression with Ryle’s tube (14F) was performed which drained about 4 L of gastric fluid in the first 24 hours. He responded to this initial conservative approach.

Further evaluation with contrast-enhanced CT scan of abdomen and pelvis revealed giant right hydronephrosis occupying most of right abdomen with thinned-out renal parenchyma with non-dilated right ureter (figures 2 and 3) and associated gastric dilatation (figure 4) due to compression of the second and third parts of the duodenum. A TC-99m EC renal scan showed hydronephrotic, obstructed and poorly functioning right kidney with differential function of 8% with normally functioning and excreting left kidney.

Figure 2.

Contrast-enhanced CT scan of abdomen (transverse section) showing right-side giant hydronephrosis.

Figure 3.

Contrast-enhanced CT scan of abdomen (coronal section) showing right-side giant hydronephrosis.

Figure 4.

Contrast-enhanced CT scan of abdomen showing gastric dilatation.

Treatment

The percutaneous nephrostomy tube placement (12 French) was performed, which drained about 3 L of urine/day for the first few days followed by minimal output (<20–30 mL) for the next 15 days. After proper counselling and consent, the patient underwent laparoscopic converted to open simple nephrectomy due to occurrence of massive bleeding while dealing with intra-abdominal perirenal dense adhesions. On surgical exploration, massively dilated renal pelvis and collective system (baggy kidney) with ureteropelvic junction stenosis with lots of perinephric adhesions was noted. The postoperative period was uneventful. The abdominal drain was removed after 24 hours of surgery and the patient was discharged on the third day.

Outcome and follow-up

At 6 months’ follow-up, the patient was asymptomatic and was doing well. Ultrasound whole abdomen showed solitary normal left kidney with minimal postvoid residual volume.

Discussion

GH is a rare congenital urological entity. More than 600 cases have been reported worldwide in literature until now, with most cases reported within the last 15 years.¹ It is defined as the presence of more than 1 L of fluid in the collecting system.² It is considered to develop gradually over a prolonged period. The causes of GH may include PUJ obstruction, ureteric stone, upper tract neoplasm, trauma and bladder outlet obstruction.³ But the amount of fluid in renal pelvic system >2 L is rarely reported. In our case, GH (containing ~4 L of urine) due to PUJ obstruction led to acute mechanical duodenal obstruction.

Ureteropelvic junction obstruction often presents with flank pain or vague abdominal pain, Dietl’s crisis, haematuria and fullness of flank region due to enlarged hydronephrotic kidney. GH may also present with vague symptoms like nausea, dyspepsia, urinary tract infection, renal insufficiency, gross haematuria after trauma, or compressive symptoms like bowel or gastric obstruction and respiratory distress.^{4 5} Mechanical duodenal or gastric outlet obstruction is a rare presentation of a GH. In literature, only handful cases of such kind are reported.^{6 7} GH is usually unilateral in most cases but in 15%–25% of cases bilateral presentation may be seen.

Ultrasonography and CT scans are used as main modalities for diagnosis of hydronephrosis and GH. GH can be defined as the presence of hydronephrosis occupying a hemiabdomen, which meets, or extends beyond the midline, and which extends at least five or six vertebral bodies in length.^{8 9} Contrast-enhanced CT of the abdomen and the pelvis is considered as the ‘gold standard’ for an accurate diagnosis of GH. The differential diagnoses of GH may include massive ascites, intraperitoneal cysts, renal or adrenal retroperitoneal cysts and ovarian cysts or tumours.^{5 9 10}

The standard treatment for GH in non-functioning or poorly functioning kidney is laparoscopic, robotic or open simple nephrectomy. The laparoscopic and robotic nephrectomy may be a difficult procedure for such a GH kidney, in presence of previous abdominal surgery or intra-abdominal adhesions, but experienced surgeons may opt for laparoscopic or robotic nephrectomy. The available options in a functional kidney include percutaneous nephrostomy tube placement, reduction pyeloplasty with nephropexy calico-ureterostomy and calico-cystostomy.5 7 9 10 The mechanical or mass effects secondary to GH usually subside after nephrectomy or with chronic urinary decompression.

Learning points.

• Giant hydronephrosis is a rare clinical entity. The causes may include pelvic-ureteric junction obstruction, ureteric stone or tumour, ureteric stricture due to trauma or inflammatory diseases, vesicoureteric growth, bladder mass and bladder outlet obstruction.

• In cases of delayed presentation, it may lead to non-functioning or poorly functioning kidney on affected side.

• Rarely, acute duodenal obstruction may be seen due to extrinsic compression by giant hydronephrotic kidney.

• It may respond to urinary decompression with nephrostomy catheter placement or simple nephrectomy. An early management should be instituted to prevent further deterioration of renal function and to reduce complication rates of pyeloplasty.