Magnetic Resonance Imaging in Proximal Venous Outflow Obstruction.

BACKGROUND: Proximal venous outflow obstruction (PVOO) in the abdomen and pelvis is increasingly recognized as an important contributor to venous disease of the lower extremity. There are currently no guidelines regarding a noninvasive screening tool for PVOO, although magnetic resonance venography (MRV) is commonly used in many practices. The objective of this study was to determine the value and utility of MRV in diagnosis and screening for PVOO. METHODS: This retrospective study consisted of 46 consecutive patients, all of whom presented with signs and/or symptoms of PVOO and were evaluated with MRV followed by intravascular ultrasound (IVUS) and venography. Of these 46 patients suspected to have PVOO based on clinical evaluation, 24 patients had PVOO confirmed with IVUS and venography and PVOO was not observed on IVUS and venography in the remaining 22 patients. The MRV of these 46 patients was retrospectively reviewed in a blinded fashion and then correlated with IVUS and venography by 1 vascular surgeon. A scoring system was developed to define the types of radiography findings that were observed: normal, suspicious, and abnormal. RESULTS: When compared with IVUS and multiplane venography, the interpretation of MRV had a sensitivity of 100% and a specificity of 22.7%. The positive predictive value of MRV was 58.5%, and the negative predictive value was 100%. CONCLUSIONS: The high sensitivity (100%) and low specificity (22.7%) of MRV suggest that it can be a screening tool at best, used only to rule out PVOO; it cannot be used to confirm PVOO, given its a 41.5% false positive rate. Thus, the development of a different, noninvasive diagnostic test that can more accurately assess patients with suspected PVOO during the initial evaluation of their lower-extremity venous disease should be explored.

Hyperbaric oxygen therapy for sudden sensorineural hearing loss: a prospective trial of patients failing steroid and antiviral treatment.

OBJECTIVE: To investigate the safety and efficacy of hyperbaric oxygen therapy (HBOT) in adult patients with sudden sensorineural hearing loss (SSNHL) who fail standard of care steroid and antiviral therapy. STUDY DESIGN: Prospective cohort study. SETTING: An urban tertiary referral center. PATIENTS: Nine adult patients presenting with SSNHL from December 2002 through February 2004. Patients with acute onset SSNHL of greater than 30 dB in three contiguous frequencies who failed to show audiometric improvement after 2 weeks of systemic steroids and antivirals were enrolled. INTERVENTIONS: Study patients received HBOT at 2.0 atmospheric pressure for 90 minutes while breathing 100% oxygen under a clear plastic hood in the chamber. Treatments were administered daily for 10 days over a 2-week period. MAIN OUTCOME MEASURES: Pre-and postHBOT mean hearing gains measured in decibels for pure-tone audiometry at 0.5, 1, 2, 3, and 4 KHz for bone and additional 8 KHz for air; pure-tone averages for air and bone; speech reception thresholds; and speech discrimination levels. Patient-reported subjective recovery rates (completely, substantially, partially, not improved) were also recorded. RESULTS: Overall, two patients had a dramatic improvement, and one patient had a dramatic improvement in his speech discrimination without improvement in other audiometric measures. Six patients had no demonstrable hearing gains. Two patients had complications of serous otitis media requiring myringotomy and pressure equalizing tube placement. No other complications were observed. CONCLUSIONS: Secondary HBOT after failure of systemic steroid and antiviral therapy may be associated with hearing gains in some patients with SSNHL.