Novel Use of Time-Resolved Magnetic Resonance Angiography to Evaluate Retrograde Lumbar Vein Flow and Epidural Venous Plexus Enhancement in Chronic Headache Patients With and Without Nutcracker Physiology.

OBJECTIVE: Compression of the left renal vein by the superior mesenteric artery, known as nutcracker phenomenon (NCP), can cause retrograde flow and congestion in communicating venous systems. It has recently been speculated that NCP can result in retrograde flow and congestion of the lumbar veins and epidural venous plexus (EVP), thereby affecting the central nervous system. This study describes the novel use of time-resolved magnetic resonance angiography (trMRA) to evaluate for retrograde left second lumbar vein (L2LV) flow and early EVP enhancement in patients with chronic daily headache (CDH) with and without NCP. METHODS: A retrospective analysis was performed of 31 patients with CDH (27 females and 4 males; median age, 38 years [range, 18-63 years]) who underwent trMRA centered over the L2LV to evaluate the direction of blood flow and presence of early EVP enhancement from May 2020 to March 2022. Descriptive statistics were performed, and anatomic associations were analyzed in patients with and without retrograde L2LV flow and early EVP enhancement. The accuracy of magnetic resonance imaging findings in detecting these flow patterns was also assessed. RESULTS: Patients with NCP who demonstrated narrowing of the left renal vein, a positive beak sign ( P = 0.052), decreased aortomesenteric distance ( P = 0.038), and decreased SMA angle demonstrated increased rates of retrograde L2LV flow and early EVP enhancement. A positive beak sign was 83% specific, and an aortomesenteric distance of ≤6.5 mm was 61% sensitive and 83% specific for identifying retrograde L2LV flow with early regional EVP enhancement in patients with CDH. CONCLUSIONS: Retrograde L2LV flow with early EVP enhancement in CDH patients can be effectively evaluated using trMRA and was seen with greater propensity in those patients with NCP.

Daily persistent headache with nutcracker physiology and spinal epidural venous congestion: Treatment with lumbar vein embolization.

Nutcracker phenomenon (NCP) can cause various congestion syndromes secondary to the superior mesenteric artery (SMA) compressing the left renal vein (LRV) resulting in venous reflux. It has recently been suggested that reflux into the lumbar vein (LV) and epidural venous plexus (EVP) may cause headaches in some patients with NCP. This report illustrates an example of a patient with refractory headaches and imaging findings suggestive of NCP that underwent treatment with percutaneous LV embolization. The patient is a 60-year-old female with daily persistent headaches for 5 years that failed numerous headache preventative medications. Time-resolved magnetic resonance angiography demonstrated NCP with reflux and congestion of the LV and EVP. Catheter-based venography confirmed these findings and the patient was treated with percutaneous embolization of the LV. This case report demonstrates the use of LV embolization to prevent EVP reflux and treat daily headaches due to NCP. The patient's headache resolved the next day. She has been headache-free for 5 months post-treatment. These findings support prior data suggesting that NCP can cause retrograde LV flow, EVP congestion, and elevated cerebrospinal fluid pressures leading to daily persistent headaches. Percutaneous embolization of the LV may be a minimally invasive treatment option for refractory headaches in patients with NCP, retrograde LV flow, and EVP congestion.

Radiation Segmentectomy for the Treatment of Primary Hepatic Malignancies of the Caudate Lobe: A Case Series.

PURPOSE: Tumors involving the caudate lobe present a unique therapeutic challenge due to their complex anatomy and the safety and efficacy of locoregional therapy can be variable. The purpose of this study is to analyze the outcomes of radiation segmentectomy for primary caudate lobe tumors. MATERIALS AND METHODS: Eight patients [5 women and 3 men; median age = 69 y (range 50-79)] that underwent transarterial radioembolization (TARE) using yttrium-90 (Y90) glass microspheres for primary caudate lobe tumors (hepatocellular carcinoma = 6, intrahepatic cholangiocarcinoma = 2) from August 2017 to March 2021 were retrospectively analyzed. Descriptive statistics, treatment parameters, tumor response (using modified response evaluation criteria in solid tumors), adverse events [using common terminology criteria for adverse events (CTCAE)], and survival outcomes were evaluated. RESULTS: Eight primary caudate lobe tumors with a median size of 2.2 cm [interquartile range (IQR), 1.7-3.3] and Child-Pugh class A liver function underwent TARE of the caudate lobe. The median radiation dose was 596 Gy (IQR 356-1585), median total activity was 0.84 GBq (IQR 0.56-1.31), median specific activity was 473 Bq/sphere (IQR 226-671), and the median number of Y90 microspheres used was 1.4 million (IQR 1.2-3.4). All complications were CTCAE grade 1, and no clinically significant hilar plate complications were observed. In targeted tumors, complete response was seen in all patients.  At a median follow-up period of 16.6 months (IQR 6.6-21.6) 75% (6/8) of patients were alive with no in-field progression. CONCLUSION: Radiation segmentectomy of primary caudate lobe tumors appears effective and is well tolerated in this limited case series within the described treatment parameters. LEVEL OF EVIDENCE: Level 4, Case Series.

Thoracic epidural lipomatosis associated with syrinx: A case report.

Epidural lipomatosis with associated syrinx formation is an exceedingly rare clinical entity. In this case report we present a 48-year old female who initially presented with symptoms of progressive myelopathy and later developed urinary incontinence. Her imaging studies showed upper thoracic epidural lipomatosis and associated spinal stenosis, cord compression and a mildly expansile right paracentral syrinx at C7-T1. She underwent a decompression surgery which provided her with partial symptomatic relief. On MRI, there was a mild decrease in the size of syrinx and some improvement in the degree of spinal stenosis. However, the subsequent clinical improvement supported the possibility that spinal compression caused by epidural lipomatosis could have resulted in syrinx formation. Therefore, such cases can be appropriately treated with spinal decompression surgeries or syrinx shunting procedures.

Association between Drug Use and In-hospital Outcomes after Infrainguinal Bypass for Peripheral Arterial Occlusive Disease.

BACKGROUND: Drug abuse may affect lower extremity vessels due to ischemia following intra-arterial injections, vasospasm, arterial and venous pseudoaneurysms, arteriovenous fistulae, vasculitis, and complicated abscesses. Little is known about the outcomes of lower extremity bypass (LEB) for peripheral arterial disease (PAD) in patients with a history of drug abuse disorder. The aim of this study is to evaluate the outcomes of LEB in this patient population. METHODS: A retrospective study of the Premier Healthcare Database 2009-2015 was performed. In-hospital complications, mortality, and hospitalization costs were assessed in patients with a history of drug abuse disorder (opioids, cannabis, cocaine, sedatives/hypnotics/anxiolytics, and hallucinogens/methamphetamine/psychoactive drugs) who underwent LEB for PAD. Multivariable logistic and generalized linear models were utilized to study the association between drug use/misuse and in-hospital outcomes after LEB. RESULTS: Our cohort included 50,976 patients, of which 967 (2%) had a history of drug abuse disorder on admission. The majority of drugs were cannabis (38.5%), followed by opioids (21.5%) and cocaine (14.5%). Patients with a history of drug use/misuse were significantly at a higher risk of developing complications during their hospital stay (71.9% vs. 64.2%, P < 0.001) including acute renal failure (11.8% vs. 9.1%), stroke (1.6% vs. 0.6%), respiratory complications (pneumonia and respiratory failure) (15.0% vs. 9.6%), hemorrhage/shock (36.2% vs. 31.8%), vascular or graft-related complications (29.8% vs. 26.4%), wound complications (9.1% vs. 6.3%), cellulitis (8.5% vs. 6.8%), and sepsis (2.1% vs. 1.2%, all P < 0.001). In addition, drug users were found to have higher risk of concomitant major amputations compared to nondrug users (2.0% vs. 0.9%, P < 0.001). On multivariable analysis, no difference was noted between the 2 groups in terms of in-hospital mortality and concomitant major amputations. However, drug use/misuse was associated with 57% higher odds of overall in-hospital complications (odds ratio [OR] 1.57, 95% confidence interval [CI] 1.34-1.83, P < 0.001), a prolonged length of hospital stay (median: 7 days vs. 5 days in nonabusers, P < 0.001), and higher hospitalization costs compared to nonusers (adjusted mean difference: OR $3,075, 95% CI $2,096-$4,055, P < 0.001). CONCLUSIONS: Drug use/misuse is significantly associated with increased odds of in-hospital complications, longer hospital stays, and higher hospitalization costs following LEB. Vascular surgeons need to pay special attention to this patient population and explore interventions to decrease the morbidity and economic burden associated with drug use.