Abstract: SA-PO1223
Preserved Doppler Flow Does Not Exclude Allograft Torsion: A Diagnostic Lesson from a Simultaneous Pancreas-Kidney Recipient with Late-Onset Ureteral Obstruction
Session Information
- Transplantation: Clinical - Complications, Pediatrics, and Multi-Organ Considerations
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2002 Transplantation: Clinical
Authors
- Montejo, Carlos, University of Vermont, Burlington, Vermont, United States
- Haq, Kanza, University of Vermont, Burlington, Vermont, United States
- Prikis, Marios, University of Vermont, Burlington, Vermont, United States
Introduction
Renal allograft torsion is underdiagnosed in simultaneous pancreas-kidney (SPK) transplantation. Clinical teaching emphasizes absent or reversed Doppler flow as the hallmark, yet this reflects vascular pedicle involvement specifically. When torsion affects the ureter selectively, vascular flow may remain normal, creating a diagnostic blind spot that delays recognition and intervention.
Case Description
A 48-year-old SPK recipient (baseline creatinine 1.1–1.3 mg/dL) presented five years post-transplant with abdominal pain, reduced urine output, and leukocytosis (WBC 41.5 K/cmm). Creatinine peaked at 5.1 mg/dL. Renal Doppler showed preserved vascular flow with a normal resistive index. Allograft biopsy (acute tubular necrosis, thrombotic microangiopathy, rejection-negative) and urine culture (Enterobacter cloacae) were non-diagnostic. Diagnosis was established by serial cross-sectional imaging with non-contrast CT that demonstrated caudal allograft migration from the left iliac fossa to the lower pelvis, a more horizontal axis, and progressive pelvicalyceal dilatation, consistent with the imaging signature of allograft torsion. Nephrostogram confirmed complete proximal ureteral obstruction. Severe coronary artery disease and heart failure precluded surgical nephropexy. Under IR guidance, a guidewire-catheter combination negotiated the kinked ureter, establishing drainage. Creatinine recovered to 1.5–1.7 mg/dL and the patient is maintained with a long-term indwelling nephrostomy tube.
Discussion
This case emphasizes three important points. First, normal Doppler does not exclude torsion. Ureteral torsion without vascular compromise is a distinct entity missed when Doppler is treated as the sole diagnostic gate. Second, serial CT comparison is critical since allograft migration and axial change are pathognomonic and invisible on flow imaging alone. Third, IR-guided ureteral negotiation is a feasible, graft-preserving alternative when surgery is prohibitive (not previously documented in SPK-related allograft torsion). Torsion must be included in the differential of any unexplained SPK graft dysfunction, regardless of Doppler findings.