Postrepair Pitfalls: Recurrent Loin Pain Hematuria Syndrome Following Nutcracker Syndrome Correction

Introduction: Loin Pain Hematuria Syndrome (LPHS) was first described in 1967 as a rare idiopathic condition of severe unilateral or bilateral loin pain associated with microscopic or macroscopic hematuria. We report a patient with persistent LPHS despite renal autotransplantation (AT) for nutcracker syndrome (NCS) Case Description: A 42-year-old female with a history of nutcracker syndrome s/p autologous left renal transplant seven months ago presented to the ED with left lower quadrant abdominal pain for one month, worsening in the past three days. She stated intractable pain 10/10 in intensity, leading to syncope and associated with intermittent gross hematuria, nausea, and vomiting. On examination, she had left lower quadrant and suprapubic abdominal tenderness. Labs showed BUN-9 mg/dL, Creatinine – 1 mg/dL, WBC 10 *3/µL, Hemoglobin – 10.2 g/dL. Urinalysis was positive for large blood, 21-50 RBC, 0-5 WBC, but negative for UTI. Ultrasound KUB and CT abdomen showed unremarkable left and right kidney with normal enhancement without intrarenal stones or hydronephrosis. MRA abdomen and pelvis showed patent renal arteries and veins bilaterally. She was diagnosed with persistent LPHS despite renal autotransplantation, and her pain was appropriately managed with opioid medications and discharged with outpatient follow up to urology and pain management. Discussion: LPHS is a diagnosis of exclusion with no identifiable primary kidney pathology and a prevalence of 0.012%, predominantly in women. The pain is among the most severe in medicine and often leads to narcotic dependency. Possible causes include renal vascular disease or vasospasm, ureteral peristalsis abnormalities, or intratubular crystal deposition. Treatments include opioids, nerve block, renal denervation, autotransplantation, neurectomy, or nephrectomy. Aber and Higgins first proposed renal AT for long-term relief. After AT, most patients are expected to be weaned off narcotics. Our patient had recurrent chronic pain at the site of autotransplanted kidney, suggesting that AT was ineffective for long term pain control. We report this case of failure of renal AT to relieve pain in NCS, suggesting re-evaluating its efficacy in tackling LPHS and to carefully select patients who may benefit from it.