Correlation of Imaging and Hemodynamic Findings with Clinical Outcomes for Diagnosis of Left Renal Vein Compression Syndrome.

Purpose: Left renal vein compression syndrome (LRVCS) remains a challenging diagnosis. This study aimed to correlate imaging and hemodynamic findings with clinical outcomes for patients with LRVCS.

Materials and methods: A retrospective review of 66 renal venography procedures with or without intravascular ultrasound (IVUS) was performed from 2017 to 2023 at a single institution. Patients with prior LRVCS treatment or other indications were excluded (n = 11). Primary outcome measure was correlation of catheter-based endovascular (CBE) findings with clinical outcomes (n = 55). Secondary outcome measures included correlation of CBE findings and LRV (i.e., beak) angle > 32°, beak sign, aortomesenteric angle (AMA < 41°), and hilar-to-aortomesenteric ratio (HTAMR ≥ 4.9) on cross sectional imaging. Descriptive statistics, chi-square testing, and ROC analyses were used.

Results: Of the 55 patients, 52 (94.5%) were females (median age 31, range 14-72) and 56.4% (n = 31) had a diagnosis of LRVCS on CBE evaluation. A renocaval pressure gradient of ≥ 3 mmHg, presence of collaterals, and > 50% area stenosis on IVUS were significantly associated with CBE diagnosis of LRVCS (p < 0.001). Surgical treatment (renal autotransplantation or LRV transposition) was recommended to all patients with CBE diagnosis of LRVCS (n = 31). 81.2% (18/22) of patients who underwent surgery reported symptom resolution or improvement. When the cross sectional imaging measurements were compared with CBE evaluation, AMA was the most sensitive (100%), HTAMR and beak sign were highly specific (93.3%), and beak angle was the most predictive (77.4% sensitivity; 86.7% specificity).

Conclusion: CBE diagnosis of LRVCS was highly predictive of surgical candidacy and post-surgical symptom resolution. The presence of collaterals, > 50% area stenosis on IVUS, or a renocaval pressure gradient ≥ 3 mmHg had a significant association with a CBE diagnosis of LRVCS.