Retroperitoneal fibrosis in four cats following renal transplantation

Abstract

Four cats developed fibrosis within the retroperitoneal space following renal transplantation. In human transplant patients, retroperitoneal fibrosis is an uncommon complication following surgery and may be secondary to operative trauma, infection, deposition of foreign material in the operative field, urinary extravasation, and perirenal hemorrhage caused by trauma to the allograft. Possible causes of fibrosis in the cats of this report include abdominal inflammation associated with allograft rejection, pyelonephritis, and septic peritoneal effusion. All of the cats of this report were readmitted to the veterinary teaching hospital following renal transplantation because of recurrence of azotemia 1 to 5 months after transplantation. Abdominal ultrasonography revealed a 2- to 4-mm-thick capsule surrounding the allograft in 2 of 4 cats, hydronephrosis in 4 cats, and hydroureter proximally in 2 cats. An exploratory laparotomy was performed in all cats to remove the fibrotic tissue causing the ureteral obstruction. Normal renal function was restored in all cats following surgery. Histologic evaluation of biopsy specimens revealed smooth muscle (3 cats) and fibrous connective tissue (4). All 4 cats, regardless of the cause, responded well to surgical resection of the scar tissue that was causing a ureteral obstruction. None of the cats had recurrence of obstruction following surgery.

Partial ablation of a para‐ureteral pseudocyst without ureteronephrectomy in a cat

“…Only a few case reports of retroperitoneal masses in cats have been described (Aronson 2002, Liptak and others 2004, Marvel and MacPhail 2013): fibrous masses following renal transplantation (Aronson 2002), sublumbar abscess associated with discospondilitis (Packer and others 2005), infarction (Ragni and Fews 2008) and urinoma (Lemire and Read 1998, Moores and others, 2002, Worth and Tomlin 2004, Pollaci and Nicoli 2011). …”

Validation of a model of feline ureteral obstruction as a tool for teaching microsurgery to veterinary surgeons

“…Experienced surgeons were recruited for their expertise relating to microsurgery . Specifically, criteria for inclusion of expert microsurgeons were >10 years experience with ureteral surgery, performance of at least 10‐15 feline ureteral surgeries or comparable laboratory animal microsurgeries per year, and significant experience with feline renal transplantation.…”

Ethical considerations in feline renal transplantation

“…However, it can also lead to post-operative pain and there is a risk of complications, such as transplant rejection, infections , retroperitoneal fibrosis (Aronson, 2002;Wormser et al, 2013), hypertension (Kyles et al, 1999), neoplasia (Wooldridge et al, 2002) and diabetes mellitus Case et al, 2007;Gregory, 2007). Kidney implantation may shorten a cat's life through peri-operative mortality (Adin et al, 2001) or may extend a cat's life, perhaps for several years (Schmiedt et al, 2008).…”