Ureterocalicostomy - Indications and Contraindications

Introduction

Ureterocalicostomy is a procedure to preserve renal function and is done by connecting the ureter to the lower pole of the kidney. Calyces are parts of the kidney where urine collection begins, and each kidney comprises up to six to ten calyces and is present in the outer edges of the kidneys. Ureterocalicostomy surgically connects nondilated healthy ureters proximal (close to the center) to the lower calyceal system. The lower calyceal system is exposed by removing the most dependent portion of the lower pole of the kidneys. This is done to divert peripelvic fibrosis (scarred and contracted renal pelvis) with a long proximal ureteral stricture or ureteropelvic junction. Stricture is simply the narrowing or constriction of the ureter, restricting urine flow from the bladder.

Neuwirt initially described ureterocalicostomy in 1947. Advanced or modern ureterocalicostomy was described in 1976. Priorly the procedure was performed with minimal amputation of the lower pole of the kidney. But this leads to anastomotic stricture and obstruction. Hawthorn et al. suggested the liberal resection of the lower pole tissue, extending towards the anterior extremity to the calyx to be joined to the ureter.

This frees the ureter caliceal attachments from the neighboring cortical tissue. The need for ureterocalicostomy has increased because of prenatal ultrasonography, which helps in uretero-pelvic junction (ureteropelvic junction obstruction) diagnosis and the complications of pyeloplasty.

What Are the Indications for Ureterocalicostomy?

Pyeloplastyis a procedure that is done for uretero-pelvic junction obstruction. It is done to repair blocks in the ureter near the exit of the kidney. A failure in this procedure leads to peripelvic fibrosis or leaves an extended gap between the renal pelvis and the non-obstructed proximal ureter. The kidney can be retrieved by ureterocalicostomy. Ureterocalicostomy may be preferred in uretero-pelvic junction obstruction or proximal stricture associated with a small intrarenal pelvis as a primary procedure. In retreatment cases, open (surgical approach where organs are exposed through incisions) or percutaneous (surgical access to organs through a needle) pyeloplasty and balloon dilatation carry high stricture recurrence rates. If an extended ureter length is not included during the procedure, preferred surgery would be retrograde endopyelotomy and an Acusize catheter (minimally invasive). Another preferred method would be ureteropyelostomy.

Ureterocalicostomy is performed in uretero-pelvic junction cases associated with malrotated or horseshoe kidneys, where performing a standard pyeloplasty will not give the desired outcomes.

The other possible procedure for ureterocalicostomy includes :

• Autotransplantation with or without a boari flap pyelovesicostomy.

• Long-term nephrostomy tube.

• Ureteral stent placement.

• Renal capsule.

• Peritoneal or pericardial flap.

• Davis was intubated with a urethrostomy.

• Buccal mucosa graft.

• Nephrectomy.

A nephrectomy should be performed based on the level of obstructed kidney function and the contralateral kidney's function. If the affected kidney has a renal function of less than 25 percent, surgery may be at risk for failure.

What Are the Clinical Symptoms of Obstruction?

Clinical signs include:

• Urosepsis.

• Failure to thrive.

• Flank pain.

• Nausea.

• Vomiting.

• Dietl crisis (vomiting during rapid diuresis or large volume liquid intake).

• History of pyeloplasty.

• Ureteroscopy.

• Endopyelotomy.

• Renal stones.

• Cancer.

• Trauma.

What Is the Pathophysiology of Ureterocalicostomy?

Peripelvic fibrosis is caused due to failed pyeloplasty or stone diseases, inflammatory processes, trauma, or other surgical procedures. Occasionally the same can be observed with severe obstruction in individuals with transplanted kidneys. The transplanted ureters become devascularised during harvest. Histologic findings are nonspecific in cases of benign ureteral strictures. There is prominent scar formation with collagen deposition and inflammatory infiltrate. The obstruction can lead to impairment of renal function, infection, pain, or renal calculi.

What Is the Epidemiology of Ureterocalicostomy?

The most frequent indication of ureterocalicostomy is pelvic fibrosis, along with proximal ureteral stricture or intrarenal pelvis, after multiple failed pyeloplasty attempts. However, this is an extremely rare case; only 0.5 percent of the cases need intervention with ureterocalicostomy. Likewise, the possibilities for horseshoe kidneys with the intervention of ureterocalicostomy are extremely rare, and few cases have been reported. Similarly, cases of ischemic fibrosis of the renal pelvis, extensive fibrosis after surgery for the upper urinary tract stone disease, or following ablative techniques such as radiofrequency and cryotherapy of lower pole renal masses.

Relevant Anatomy for Ureterocalicostomy:

The ureteral length depends on the individual's height; the average length is around 20 to 30 cm. The size of the lumen circumference is 4 to 10 mm, depending on its location. The uretero-pelvic junction, and the overpass where the ureteropelvic junction crosses above the bifurcation of the iliac arteries and the ureterovesical junction, are considered the narrowest areas of the ureteropelvic junction.

When the ureters enter the pelvis, they move anterior to the iliac vessels and posterior to the gonadal vessels. In females, the ureter is posterior to the ovaries and lateral to the infundibulopelvic ligament. In men, the vas deferens swing anterior to the ureter before the ureter enters the bladder. In women, the ureter is posterior to the uterine arteries (the water under bridge analogy). The ureter is close to the uterine cervix before reaching the intramural bladder.

The ureter has numerous sources of blood supply. The main supply source to the ureter is the renal artery which branches out with the gonadal artery. In addition, the aorta provides multiple small branches as the ureter takes the route toward the retroperitoneum.

The iliac, uterine, vesical, and hemorrhoidal arteries also supply blood to the ureter in the pelvis. The venous drainage is combined with the arteries. Understanding the vascular supply is critical in ureteral surgery because destruction or obstruction in blood vessels supplying the ureter leads to complications such as leak and stricture. Lymphatic drainage of the superior ureter connects the renal lymphatics to the lumbar nodes. The middle ureter drains to the internal and common iliac nodes. The pelvic ureter lymphatic vessels drain to the internal iliac and vesical nodes.

What Are the Contraindications of Ureterocalicostomy?

The contraindications include:

• An untreated and active urinary tract infection is the prime contradiction for any stricture surgery.

• Uncorrected or unattended bleeding susceptibility.

• Long-term stenting may be appropriate or an adjunct in cases of terminal malignancy.

• Contraindicated in extremely old individuals prone to surgical risk.

• It is contraindicated in individuals being able to tolerate internal stenting.

• The nephrectomy may be the apt procedure for individuals with less than 10 percent renal function, as recovery is less likely.

• Ureteral obstruction because of retroperitoneal malignancy, retroperitoneal fibrosis, or lymphadenopathy.

• Strictures caused by urinary tuberculosis untreated and those that remained stable for three to six months. It is contraindicated to avoid post-inflammatory scarring.

Conclusion

Ureterocalicostomy is often performed in individuals with failed pyeloplasty. Ureterocalicostomy is often considered in conditions like uretero-pelvic junction obstruction associated with renal fusion, ascent or rotation, a shorter ureter, or an intrarenal pelvis. As of today, ureterocalicostomy is a reliable rescue procedure.