Biomedical subjects
Publications and source records attributed to M Sapoval.
A case of arteriovenous fistula and false aneurysm of the internal mammary artery due to sternotomy is reported. The diagnosis was suspected by echo-Doppler and confirmed by arteriography, allowing percutaneous embolization in the same session.
PURPOSE: To evaluate the safety and efficacy of a porcine-derived gelfoam, Curaspon, for the temporary occlusion of the visceral arteries. METHODS: Curaspon was used for the selective embolization of segmentary hepatic, unilateral polar renal, and single lumbar arteries of 10 pigs under general anesthesia. Sequential angiographic checks were carried out and the pigs killed between 3 days and 2 weeks later. Macroscopic and microscopic studies using standard techniques were used to evaluate the immediate efficacy of embolization, duration of and completeness of recanalization on angiography, macroscopic appearance of target-organ ischemia, and microscopic analysis of inflammatory reaction. RESULTS: Immediate arterial occlusion was obtained in all cases. Renal arteries showed a total recanalization in 63% of cases on day 7 and 100% on day 14. Total hepatic recanalization was obtained in 100% of animals on day 7. All lumbar arteries were recanalized on day 14. Microscopic analysis in the kidney revealed a mild inflammatory reaction and a progressive lysis of the Curaspon (87% of samples at day 3 showed a persistence of Curaspon and 5% at day 14). In some cases, localized and partial destruction of the arterial wall was visualized. In the liver the same patterns were observed but resolved more completely and more rapidly. CONCLUSIONS: Curaspon is an efficient material for the temporary occlusion of visceral and parietal arteries in pigs. However, arterial aneurysms were observed and a relationship of these with the material cannot be excluded.
PURPOSE: To test the effectiveness of endoluminal exclusion of the false lumen in experimental thoracic aortic dissection by occlusion of the entry site with a balloon-expandable endograft. MATERIALS AND METHODS: Thoracic aortic dissections were induced surgically in six beagles. The endograft consisted of an ultrathin, 12-mm-wide polyester tube sutured over a Strecker stent that was already crimped onto an angioplasty balloon. Fluoroscopic and intravascular ultrasonographic (IVUS) guidance were used. Endografts were introduced by means of femoral arteriotomy, via a 12-F sheath positioned in the aorta, and were then expanded on the angioplasty catheter. RESULTS: IVUS and aortography showed an extensive thoracic dissection in all animals. Only four of six endografts were successfully placed. At 1 month, all thoracic endografts were patent, but the false lumen was never thrombosed. IVUS scans demonstrated a malpositioned endograft in two cases and persistent reentry in all cases. CONCLUSION: Endovascular grafting of the aorta was feasible in experimental thoracic aortic dissection, but thrombosis of the false lumen was not achieved.
PURPOSE: To report the feasibility, safety, and effectiveness of manual thromboaspiration as a single means of declotting dialysis access. MATERIALS AND METHODS: Between April 1994 and December 1996, 59 consecutive conduits (43 polytetrafluoroethylene [PTFE] grafts, 16 native fistulas) were declotted with 8-F or 7-F angulated catheters. Unmasked stenoses were dilated. Clinical and paraclinical nephrologic surveillance (poor flow, palpation, difficulties with cannulation, increased compression times, increasing venous pressures) led to redilations and stent placements. Rethromboses were treated with further declotting by aspiration. The results are presented according to the life-table method. RESULTS: The initial success of 43 of 43 PTFE grafts (mean procedure time, 119 min +/- 29 [standard deviation]) led to a primary patency rate of 85% +/- 5% (SE) at 1 month, 33% +/- 8% at 6 months, and 24% +/- 12% at 1 year. A graft was ligated 6 days after declotting for acute bleeding in one patient given high-dose warfarin. The secondary patency rates were 86% +/- 7% at 6 months and 86% +/- 9% at 1 year, with a mean duration of patency of 5.7 months between two radiologic interventions performed to maintain or to restore patency, and 19 stents were placed at a mean follow-up of 3 months. The success rate was 81% for native fistulas, with primary patency rates of 81% +/- 10% at 1 month, 74% +/- 14% at 6 months, and 60% +/- 27% at 1 year; secondary patency rates of 81% +/- 12% at 6 months and 81% +/- 18% at 1 year. CONCLUSION: Thromboaspiration is a safe and effective method for declotting dialysis access, yielding a low rethrombosis rate during the first month. Overall radiologic management with reintervention on average every 6 months results in high secondary patency rates at 1 year (81%-86%).
PURPOSE: To report the value of selective placement of self-expandable stents (Wallstent and Craggstent) for the treatment of limitations and, occasionally, of complications of dilation in hemodialysis access, and especially for delaying restenosis. MATERIALS AND METHODS: This is a retrospective study of a 7-year period, during which 41 Wallstents and 11 Craggstents were placed in 26 polytetrafluoroethylene (PTFE) grafts, 15 native fistulas, and nine central veins of 47 patients. The indications were stenosis recoil (n = 13), recurrent restenosis within 6 months (n = 33), restenosis after 6 months (n = 3), and acute angioplasty-induced rupture (n = 1). Restenosis after stent placement necessitated redilation and percutaneous declotting and 10 additional stent placements. RESULTS: Two initial misplacements were corrected immediately. Primary patency rates for PTFE grafts were 58% +/- 10% at 6 months and 23% +/- 10% at 1 year, respectively. Secondary patency rates were 100% at 6 months and 88% +/- 8% at 1 year, respectively. For native fistulas, primary patency rates were 47% +/- 12% at 6 months and 20% +/- 18% at 1 year. Secondary patency rates were 95% +/- 6% at 6 months and 79% +/- 14% at 1 year. It was necessary to reintervene after stent placement to maintain or to restore patency every 9 months for PTFE grafts and every 7.3 months for native fistulas. When stents were placed for treatment of early recurring restenosis, the mean interval between radiologic interventions (redilations or declottings) performed to maintain or to restore patency before stent placement was multiplied by 2.1 after stent placement for both grafts (3.2 months increased to 6.9, P < .01) and native fistulas (2.9 months increased to 6.2, P < .02). CONCLUSIONS: Wallstents and Craggstents are valuable for the treatment of failure of regular dilation and they double the intervals between reinterventions for early (< 6 months) recurring stenoses in PTFE grafts and native fistulas.
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PURPOSE: The purpose of this work was to assess typical findings of Takayasu arteritis on serial CT examinations following therapy. METHOD: Serial CT studies were performed on 16 patients with early phase Takayasu arteritis. Mural or luminal changes of the aorta on successive CT scans were compared with clinical data. RESULTS: Vascular lesions progressed during follow-up in 6 of 16 patients. In one patient, progression of lesions was symptomatic. In the other five of six patients with worsening lesions, vascular progression occurred without new clinical symptoms and was first identified on CT scans. One of these five had dilatation of the ascending aorta and required aortic repair. Four others had progression of stenotic vascular lesions leading to changes in medical treatment only or in combination with either surgery or angioplasty. For two of them, CT examinations showed decreased mural lesions after changes in medical treatment. CONCLUSION: CT examinations performed in treated patients with Takayasu arteritis demonstrate either regression, stabilization, or progression of vascular lesions. Serial CT examinations may thus be useful for evaluating response to treatment.
The long-term prognosis of Takayasu's disease depends on an elective surgical treatment which requires full and accurate assessment of the lesions. We present here a retrospective study of 50 patients explored before surgery by intra-arterial digital angiography. In 92 percent of the patients the thoraco-abdominal aorta and its branches were well documented on 2 orthogonal projections performed in one single session. The high-quality intra-arterial opacification made it possible to detect incipient parietal lesions and to evaluate the lesions of the small caliber branches and the downstream bed in case of occlusion. These advantages, and the absence of morbidity in our experience, make digital panarteriography a method of choice to evaluate Takayasu's disease.
The crucial need for donors of paediatric or small sized organs has been a great obstacle to overcome in organ transplantation in children or small adults. Some progress in adapting size of the donor organs has been achieved with surgical procedures for reducing the size of donor organs, partial transplantation (single lobe of the liver or the lung) and liver partition, offering a partial solution to the insufficient supply of paediatric organs. We propose an experimental model in the dog of lung partition associated with monolateral (series I) or bilateral (series II) lobe transplantation. The results have been encouraging both in terms of quality of healing and in morphological and functional adaptation of the transplanted lobes, allowing us to apply this technique of lung partition and bilateral lobe transplantation in human patients. The outcome has been excellent in the first case after 18 months follow-up.