Post-lymphangiographic computed tomography in chylothorax after esophagogastrectomy: a case report.

Chylothorax is a rare complication of thoracic surgery. Lymphangiography has long been considered to be the standard of reference for diagnosis and post-treatment evaluation while the role of post-lymangiographic CT is debated. We report a case of chylothorax in a 68-year-old male following esophagogastrectomy for which conservative treatment and thoracic duct ligation failed. Lymphangiography performed after these attempts revealed persistent thoracic duct leakage into the right pleural space. Subsequent non-contrast CT and reformatted images clearly depicted the sources of leakage, and this documentation targeted direct percutaneous treatment. Unfortunately, the lack of access precluded the planned percutaneous CT-guided embolization of the thoracic duct. Nevertheless, this case suggests that post- lymphangiographic CT can serve as a value-added modality in the evaluation and potential treatment of chylothorax.

Chemical breakdown of technetium-99m DTPA during nebulization.

Aerosols of 99mTc diethylenetriaminepentaacetic acid ([99mTc]DTPA) used for measuring lung permeability and lung ventilation require a radioaerosol delivery system to produce an aerosol with reproducible size and radiochemical purity. To test how well nebulizers meet this requirement, radiochemical purity of aerosols produced with a jet and an ultrasonic nebulizer was evaluated. The activity median aerodynamic diameter (AMAD) and geometric standard deviation (sigma g) of radioaerosols were 0.46 micron (sigma g = 1.6) for the jet nebulizer and 0.70 micron (sigma g = 1.7) for the ultrasonic nebulizer. Paper and liquid chromatographic assays were obtained on the [99mTc]DTPA aerosol solute produced with each nebulizer. The results of these tests showed major differences in radiochemical purity. Aerosols produced in the jet nebulizer consistently showed greater than 90% of the radioactivity bound to the DTPA ligand whereas aerosols produced in the ultrasonic nebulizer showed less than 10% of the radioactivity bound to DTPA. The results support the need to test radiochemical purity of aerosols before using an aerosol nebulizer for pulmonary imaging and clearance studies.

Preliminary assessment of captopril sonography in screening for renal artery stenosis.

RATIONALE AND OBJECTIVES: We assessed the usefulness of the resistive index (RI) and renal length in predicting a significant renal artery stenosis (RAS) and evaluated the effect of captopril on the RI in kidneys with and without a significant RAS. METHODS: The RIs and renal lengths of both kidneys were measured in 39 patients who were referred for captopril renography for suspected renovascular hypertension. The difference in RIs (delta RI), the smaller RI (SRI), the difference in lengths (delta L), and the shorter length (SL) of the patient's two kidneys were determined. The accuracy of each of these parameters was calculated using captopril renography (n = 39) and arteriography (n = 9) as the gold standards. RESULTS: There was a significant difference in the delta RI (P < .05), SRI (p < .001), and delta L (p < .05) in patients with a positive captopril renogram for a significant RAS. Captopril increased delta RI (p = .052) in patients with a positive captopril renogram (n = 6). Use of an SRI threshold of less than .55 resulted in ultrasound being as accurate as captopril renography in predicting an angiographically documented stenosis of greater than or equal to 50%. CONCLUSION: The RI and renal length are useful in detecting a significant RAS. In this preliminary study, captopril was shown to increase delta RI in patients with a significant RAS, but larger prospective studies are necessary to further assess the value of captopril sonography in detecting a significant RAS.

Comparison of vasa vasorum after intravascular stent placement with sirolimis drug-eluting and bare metal stents.

The cytostatic drug, sirolimis has shown prevention in neointimal hyperplasia after stent placement. Recent studies have shown persistent inflammation seen with drug-eluting stents (DES) may result in late stent thrombosis. The aim of this study is to compare effects of bare metal stents (BMS) and sirolimis DES on the neointima and vasa vasorum in stented rabbit aortas. Stents were implanted in eight New Zealand rabbits for 9 weeks. Group I rabbits received BMS. Group II rabbits received sirolimis DES. A balloon-mounted BMS or DES was placed in the infrarenal aorta. Following euthanasia, aortas were perfused with barium sulfate and sectioned for histology. After 9 weeks the qualitative intrastent luminal diameter was fairly uniform in both the DES and the BMS. The thickness of neointima was similar in both groups. The number of vasa vasorum in the sirolimis DES increased compared with the BMS (P < 0.05). An increased number of vasa vasorum produced by the DES when compared with the BMS shows a difference in response to local vessel injury in rabbits. This result suggests that vasa vasorum may play a role in the persistent inflammation generated by sirolimis-coated stents.

Transvenous retrieval of a Greenfield filter lodged in the tricuspid valve.

A 77-year-old man had an inferior vena cava Greenfield filter placed for bilateral deep venous thrombosis acquired during a complicated hospitalization for a hip fracture. The filter migrated and lodged at the level of the tricuspid valve. We describe a transvenous retrieval approach which is safer and performed under more controlled technique than previously reported.

Direct graft puncture with use of a crossed catheter technique for thrombolysis of peripheral bypass grafts.

PURPOSE: To determine the efficacy and safety of direct graft puncture of peripheral arterial bypass grafts with placement of retrograde and antegrade catheters within the graft for thrombolytic therapy. This study also evaluated potential clinical benefit to patients. MATERIALS AND METHODS: A retrospective study was performed on 19 patients with 24 peripheral bypass grafts and lower extremity ischemia of less than 1 month duration. Thrombolysis was performed with a continuous high-dose infusion of urokinase. Successful lysis was defined as greater than 95% clot dissolution with antegrade flow within the graft. RESULTS: Technical success was achieved in 17 of 19 patients (89%). The complexity of operative intervention was diminished in 12 of 19 patients (63%). The major complication rate (16%) was significantly higher and, therefore, this technique has a role for patients in whom traditional access is not optimal, such as in those in whom access cannot be achieved or in those with long bypass grafts. CONCLUSION: Direct graft puncture with placement of catheters across the proximal and distal anastomoses of bypass grafts is a safe method of access, with a major complication rate similar to conventional access techniques. This mode of graft access demonstrates efficacious thrombolysis and acts as a conduit for ancillary procedures.

Diagnosis of renal artery stenosis in transplanted kidneys: value of Doppler waveform analysis of the intrarenal arteries.

OBJECTIVE: The objective of this study was to determine in renal transplant patients if the acceleration time and subjective assessment of dampening of the waveforms from the intrarenal arteries improves the accuracy of detecting a hemodynamically significant (> or = 50%) proximal arterial stenosis compared with measurements of peak systolic velocity from a main renal artery. MATERIALS AND METHODS: In 15 patients, the findings of 19 Doppler sonograms and corresponding arteriograms of their renal transplants were reviewed, with arteriography serving as the gold standard. Four patients had a significant proximal arterial stenosis; three were of the main renal artery and one was of the adjacent external iliac artery proximal to the anastomosis with the renal artery. RESULTS: We found a significant prolongation of the acceleration time in patients with a significant proximal arterial stenosis (p = .0004). Use of a threshold acceleration time of 0.10 sec or subjective assessment of dampening of the waveforms resulted in an accuracy of 95% in detecting a significant proximal arterial stenosis. This compared with an accuracy of 62% in detecting a significant proximal arterial stenosis using a peak systolic velocity threshold of 2.0 m/sec as the sole criterion. Using intrarenal arterial Doppler waveform parameters alone would have spared arteriography in 11 patients and would have detected three of four significant proximal arterial stenoses. CONCLUSION: In this study, Doppler waveform analysis of the intrarenal arteries improved the accuracy of screening for a significant proximal arterial stenosis. The results suggest that such analyses can be used to spare many patients with suspected renal vascular hypertension from unnecessary arteriography.

Clinical implications of internal iliac artery embolization in endovascular repair of aortoiliac aneurysms.

To overcome constraints imposed by iliac artery anatomy, the anatomic inclusion criteria for endovascular aortic aneurysm repair can be extended by means of intentional coil occlusion of one or both internal iliac arteries and extension of the distal limb of the graft into an external iliac artery. We reviewed our experience with this intervention to determine the safety and efficacy of this approach to aneurysm repair. Over a 30-month period, 84 patients underwent endovascular abdominal aortic aneurysm repair; 23 underwent intentional unilateral (22) or bilateral (1) internal iliac artery occlusion. Morbidity, mortality, and long-term clinical outcomes were evaluated in these 23 patients. Patients were specifically questioned about exercise-induced buttock and extremity symptoms. Our results showed that intentional internal iliac artery embolization to allow endovascular repair of abdominal aortic aneurysms is accompanied by significant morbidity and should be approached with caution.

Sclerotherapy with use of doxycycline after percutaneous drainage of postoperative lymphoceles.

PURPOSE: To assess the use of doxycycline as a sclerosing agent after percutaneous drainage of postoperative lymphoceles. MATERIALS AND METHODS: Symptomatic postoperative lymphoceles (n = 21) in 18 patients were treated by percutaneous tube drainage for an average of 10.8 days. Sclerosis was performed when the patient became asymptomatic, drainage had slowed to less than 30 mL/d and follow-up imaging (CT or US) showed either near complete or total resolution of the lymphocele. Doxycycline (500 mg) combined with 1% lidocaine (5 mL) was instilled into the cavity with use of a syringe after any remaining lymphocele fluid was removed through the tube. When possible, patients were instructed to perform a series of maneuvers for the next hour to distribute the sclerosing agent evenly throughout the cavity. After 1 hour, the sclerosing agent was aspirated from the cavity and the drainage tube was removed. Three patients with four lymphoceles underwent sclerotherapy immediately after percutaneous insertion of a drainage tube and aspiration of the lymphocele. No patients underwent previous sclerosis with any agent. RESULTS: Successful treatment of postoperative lymphoceles was achieved in 17 of 18 patients. Primary success was achieved in 17 of 21 lymphoceles treated. There were four lymphocele recurrences in three patients. Three of the four recurrences were successfully treated by means of repeated drainage and sclerotherapy. One recurrent lymphocele persisted after re-treatment with 1 g of doxycycline. This patient underwent successful surgical repair. There were no complications related to doxycycline sclerosis. The mean duration of drainage for initial and recurrent lymphoceles was 10.8 days (range, 0-30 days). CONCLUSION: Sclerotherapy with use of doxycycline after percutaneous drainage is an easy, safe, inexpensive, and effective means of treating postoperative lymphoceles.

Use of intraoperative ultrasonography during hepatic transplantation.

The aim of this study was to evaluate if intraoperative vascular ultrasonography is of clinical value in the perioperative management of hepatic transplant patients. Fifteen intraoperative ultrasonographic examinations were performed on 13 patients (five female, eight male) during transplantation. These patients had clinically suspected vascular compromise. Among the 13 patients studied intraoperatively, five were correctly diagnosed as having hemodynamically significant vascular compromise. Of the intraoperative vascular sonographic examinations, the results of 13 were in concordance with the surgical impression as to whether further intervention was necessary or if the procedure could be terminated. Intraoperative sonography demonstrates potential to be of aid to the surgeon in recognition of vascular compromise.

Effect of pattern of aerosol inhalation on clearance of technetium-99m-labeled diethylenetriamine pentaacetic acid from the lungs of normal humans.

The clearance rate of inhaled aerosols of technetium-99m-labeled diethylenetriamine pentaacetic acid (99mTc-DTPA) from the lungs provides a rapid, clinically useful, noninvasive index of pulmonary epithelial permeability. In order to identify a method that minimizes intrasubject and intersubject variability and thereby provides a reliable means to identify patients with abnormal values, we administered a submicronic aerosol of 99mTc-DTPA to 10 healthy, nonsmoking male subjects with either tidal breathing (Vtidal) or multiple vital capacity maneuvers (VVC). Subjects then spontaneously breathed room air while counting continued for 30 min. Monoexponential clearance rates over 7, 15, and 30 min were compared with a two-compartment, biexponential analysis over 30 min. Intrasubject reproducibility was evaluated by repeating clearance 2 to 156 days later. Monoexponential clearance following VVC at 30 min equaled 1.36 +/- 0.55%/min compared with 0.83 +/- 0.25%/min for Vtidal (p less than 0.025). VVC inhalations resulted in a larger fast compartment of 16 +/- 12% compared with 3 +/- 2% with tidal breathing (p less than 0.01). The least intrasubject variability with coefficient of variation (CV) of +/- 18% was obtained with monoexponential analyses after Vtidal during 15 min of scanning and with either breathing maneuver over 30 min. Monoexponential clearance for 30 min with Vtidal gave the least scatter between subjects, with CV of +/- 30%. These data show that simple tidal inhalations of 99mTc-DTPA followed by a monoexponential analysis of the 30-min time-activity curve from both lungs minimize the degree of variability between and among subjects and provide a predicted normal value of clearance of 0.83 +/- 0.25%/min. The development of a more rapid curvilinear clearance followed by delivery VVC suggests that several deep breaths transiently increase epithelial permeability or reduce the volume of liquid in the alveolar subphase in some regions. Resting for 20 min prior to inhaling the aerosol of 99mTc-DTPA is recommended to avoid alterations in clearance rates from deep breathing.