Torsion of the Retroperitoneal Kidney: Uncommon or Underreported?

Abstract

Vascular torsion in a renal allograft after placement in the retroperitoneum is rare and has only been reported twice in the literature. It is an extrinsically mediated process that occurs at the vascular pedicle resulting in graft compromise and potential loss. Rapid diagnosis and immediate surgical intervention may salvage allograft function. Herein, we present a unique case of a 42-year-old male that developed renal allograft torsion following a second kidney transplant placed in the retroperitoneum. Immediate detorsion did not resolve allograft dysfunction, and a biopsy revealed acute cellular mediated rejection. After antithymocyte globulin treatment, allograft function was salvaged. A review of the current literature shows that the incidence, morbidity, and long term allograft function of intraperitoneal and extraperitoneal torsion are different. As such, torsion of the retroperitoneal kidney demonstrates encouraging allograft salvage rates. Only the third case reported to date, this serves as a contribution to the growing body of literature in retroperitoneal renal torsion and reviews the risks, medication considerations, diagnostic tests, and treatment modalities in a unique disease process.

Renal Allograft Torsion: US and CT Imaging Findings of a Rare Posttransplant Complication

“…While torsion is much less common than other vascular complications, it should be included in the differential and diagnosed rapidly as immediate surgical intervention can salvage allograft function. Delays in diagnosis result in an increased risk of frank necrosis, acute cellular rejection, and possible transplant nephrectomy [ 1 ].…”

“…Data is limited regarding salvage rates of extraperitoneal torsion given that only 3 cases have been reported in the literature. Of these cases, however, all resulted in salvage of the allograft without the need for nephrectomy [ 1 ].…”

“…Torsion is a rare complication of renal transplants and can be seen with both intraperitoneal and extraperitoneal allografts [ 1 ]. Clinical presentation and diagnostic imaging are nonspecific and often result in delayed surgical exploration [ 2 ].…”

Salvage after Retroperitoneal Kidney Allograft Torsion

“…Winter et al described a case of torsion they believe resulted from the patient's increased BMI and error in surgical technique [4]. In 2014, Sosin et al reported laxity of the abdominal wall and accompanying potential large retroperitoneal space as the primary factors leading to rotation of the graft [3]. We believe that our case represents yet another situation whereby an enlarged native polycystic kidney exerted pressure and caused rotation of the renal allograft about its pedicle.…”

“…Torsion of kidneys transplanted into the retroperitoneal space is a rare complication. Only three other cases have been reported, all within the last ten years [2][3][4]. These cases represent examples of warm ischemic time in kidney transplants.…”