The patient is a premature boy, born in gestation week 26+2 with a birth weight of 1068 grams. He was treated in neonatal intensive care and suffered from both necrotizing enterocolitis, as well as grade IV intraventricular haemorrhage and posthemorrhagic hydrocephalus. His abdominal condition required two laparotomies with intestinal resections, while his posthemorrhagic condition included 32 shunt procedures/revisions (Table I). He initially underwent implantation of a ventriculoperitoneal (VP) shunt, that due to infection and peritoneal malabsorption was replaced with a ventriculoatrial (VA) shunt. Due to atrial catheter malfunction, a VP shunt was reimplanted. However, also this VP shunt had to be replaced with another VA shunt, secondary to problems with malabsorption and the development of a CSF cyst that caused right-sided hydronephrosis. Unfortunately, extensive central venous thrombosis with subsequent vena cava syndrome eventually required the removal of the second VA shunt. A pleural shunt was now being considered, but due to the large drainage volumes, this was abandoned. The urinary bladder was also considered, but due to episodes of documented non-symptomatic bacteriuria during the past year, this was believed to be a risky endeavour. Finally, a VU shunt remained a viable option, and while acknowledging the risks of urinary tract infections as well as the risk of the shunt becoming a nidus for the formation of urinary calculi, the VU shunt was deemed the best option for this patient.
The parents have consented to the publication of the case.
Preoperative work-up
An MRI of the brain was performed to rule out hematoma, subdural collections or new adhesions. Due to a left-sided posthemorrhagic ventricular dilatation, this side was chosen for the proximal catheter. CSF cultures were performed and found negative. Repeated urinary cultures showed no signs of bacteriuria. Persistent hydronephrosis was ruled out by ultrasound. Abdominal MRI showed that both kidneys were normal in size with adequate parenchymal thickness. The right ureter was found to be slightly wider than the left. A review of a previous CT scan showed a right-sided ureteric dilatation, sufficient to harbour the distal catheter. A voiding cystourethrography (VCUG) was performed to rule out vesicoureteral reflux while the bladder volume was estimated to be approximately 150 ml. A high-pressure bladder was considered unlikely, as there were no signs of bladder trabeculation or diverticulae on VCUG and both ultrasound and MRI showed a thin-walled bladder of normal size. Cystometry was not performed.
Surgical Technique
The child was positioned semi-prone with his right side slightly elevated. A radiologist experienced in ultrasound-assisted percutaneous nephrostomies (MJ) and a pediatric urologist (JS) were present for the implantation of the distal catheter. The renal pelvis was reached with a micropuncture technique (0.9 mm needle and 0.018inch guidewire) under ultrasound guidance and fluoroscopic control. Using the Seldinger technique and serial dilatation to 8 F, PTFE-coated stainless steel, 0.035 inch (0.89 mm) guidewire was placed via the ureter into the bladder (Figure 1) After a small skin incision, the distal shunt catheter was then placed 3 cm cranially to the ureteric orifice and the final position was verified with fluoroscopy (Figure 2). The shunt catheter was then tunnelled subcutaneously over the back, medially to the right scapula and connected to the shunt valve of a left-sided frontal ventricular catheter (inserted by neurosurgeons JB and US, Figure 3).
On postoperative day 2, the child developed new neurological symptoms and a CT of the abdominal cavity showed that the distal catheter had migrated 2 cm distally, close to the ureteric orifice where the ureter typically is slightly narrower. There is also the possibility of the tubing being clogged by blood. The problem was resolved by shortening and flushing the distal catheter. The catheter was shortened by 2cm (neurosurgeon EE). After this revision, the recovery was uneventful.
Outcome
Follow-up at six months included urinary cultures and a low-dose CT to rule out the development of hydronephrosis or urinary calculi, as well as any possible formation of calcifications on the distal catheter. The patient remains on a daily dose of oral prophylactic antibiotics (trimethoprim-sulfamethoxazole). At the 15-month follow-up, there have been no urinary tract or CNS infections, and no further episodes of shunt dysfunction. A new MRI of the brain was performed one year postoperatively and showed expected ventricular size and adequate location of the proximal catheter No new abnormalities have emerged on radiological imaging, apart from those related to the pre-existing condition. There have not been any problems related to the maintenance of a normal electrolyte homeostasis and the patient has not required any form of fluid or electrolyte substitution. Neurological follow-up has consisted of out-patient appointments at the neurosurgical department, initially after four weeks and further every six months