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Biomedical subjects

V S Sottiurai

Publications and source records attributed to V S Sottiurai.

At least 19 recordsLinked to original sources
PubMed1997

Revascularization of cerebral ischemia after previous bilateral extracranial-intracranial bypass procedures.

Extracranial-intracranial (EC-IC) bypass grafting procedures were specially designed for treatment of bilateral internal carotid artery occlusion. When performed in an expeditious manner, EC-IC bypass procedures have produced effective and durable results, despite the recent disfavor given to this procedure. This communication reports a 68-year-old white man who developed generalized cerebral ischemia manifested as confusion, incoherence, disorientation, ataxia, and numerous episodes of syncope daily. A cerebral angiogram revealed bilateral external carotid arteries and left solitary vertebral artery critical stenosis. Transcranial Doppler study demonstrated reduction of cerebral and vertebral-basilar perfusion. However, the patient's EC-IC bypass graft had remained patent since 1985. The patient's recurrent symptoms of global ischemia and syncope resolved after carotid endarterectomy, vein patch external carotid artery, and vertebral-to-common carotid artery transposition. This report reiterates the value of the EC-IC bypass procedure and presents the surgical management of symptomatic external carotid and vertebral artery stenosis in patients after EC-IC bypass procedures.

Aged↗
PubMed1997

Comparative results of early and delayed cannulation of arteriovenous graft in haemodialysis.

OBJECTIVE: To determine whether arteriovenous graft (AVG) can be cannulated for haemodialysis 24-48 h following placement. DESIGN AND MATERIALS: Thirty-six upper extremity Gore-Tex PTFE arteriovenous grafts were cannulated for haemiodialysis 24-36 h (n = 18) and at 10-14 days (n = 18) following insertion. The determinant parameters were compression time to control bleeding, venous back pressure, haematoma, infection and occlusion. MAIN RESULTS: In a 40 day follow-up, there were no significant difference in cannulation of AVG at 24-36 h vs. 10-14 days using the predetermined parameters. CONCLUSION: Early graft cannulation produced no adverse results than late cannulation when the diameter of the tunneller matched the diameter of the graft. Early graft cannulation was safe and recommended.

Arm↗
PubMed1996

Surgical management of brachioaxillary-subclavian vein occlusion.

OBJECTIVE: The possibility of using RING PTFE graft as venous bypass to preserve arteriovenous graft function and reduce upper extremity swelling. METHODS: Twenty-two patients with stenosis/occlusion of the brachial-axillary-subclavian vein segment in haemodialysis patients (n = 19) and patients with penetration injury (n = 3) who were not candidates for balloon angioplasty were treated with ring PTFE venous bypass in renal patients and jugular to axillary vein transposition for trauma patients and followed for 10-87 months (mean 31) using venography, Doppler analysis and Duplex scanning. RESULTS: There was no death or neurologic deficit resulting from the venous bypass. Resolution of swelling occurred in 8-48 h. 19/22 (86%) of the bypasses and 3/3 transpositions remained patent after a mean follow-up of 31 months (10-87) months. The attrition was due to AV graft occlusion (n = 2) and infection requiring graft removal (n = 1). CONCLUSIONS: Ring PTFE graft is an acceptable venous bypass for brachial-axillary-subclavian stenosis/occlusion to reduce arm swelling and preserve the function of AV grafts in patients with lesions not amendable with balloon angioplasty or thrombolytic therapy. Jugular-axillary transposition is inappropriate for renal patients.

Adult↗
PubMed1994

Femoral artery hypoplasia and persistent sciatic artery with blue toe syndrome: a case report, histologic analysis and review of the literature.

When the primitive sciatic artery remains the major artery in the thigh, the superficial femoral artery is usually poorly developed or absent. This abnormal vasculature is ascribed to the persistent embryologic arterial system which can occur unilaterally or bilaterally. Sciatic artery is known to be susceptible to aneurysmal changes. Pulsatile gluteal mass, distal embolization and, lower extremity ischemia in the sitting position are the pathognomonic clinical symptoms. Excision of the sciatic artery combined with femoro-popliteal bypass is the established recommended surgical treatment.

Aneurysm↗
PubMed1994

The role of vein patch in distal anastomotic intimal hyperplasia: an histologic characterization.

Comparison of the cumulative patency of four types of Polytetrafluoroethylene (PTFE) grafts with and without a vein patch at the distal anastomosis in one hundred and twenty ilio-femoral by-passes of sixty dogs revealed: (i) Vein patch improved patency in standard PTFE graft 10/16 (62.5%) versus without a vein patch 6/16 (27.5%) (p < 0.1). (ii) The less rigid thin wall PTFE graft did not benefit from vein patching 22/45 (48.8%) versus those without a vein patch 28/45 (62.2%) (p < 0.2). (iii) DAIH was present in all grafts with and without a vein patch and occurred exclusively at the heel and the toe of the graft plus the floor of the host artery three months after implantation. (iv) An organized fibrocellular multilamination characterized the cytoarchitecture of the DAIH. (v) A process of gradual cell transformation and orientation occurred in DAIH that spanned between the graft and the lumen. Vein patch at the distal anastomosis improved the patency of the more rigid standard PTFE grafts, and adversely affected the less rigid thin walled PTFE graft in dogs. The formation and distribution of DAIH was not altered by a vein patch at the distal anastomosis of PTFE grafts.

Anastomosis, Surgical↗
PubMed1991

Technique to prevent aortic anastomotic bleeding and kinking with bifurcated PTFE grafts.

The bifurcated polytetrafluoroethylene (PTFE) graft was introduced for use in aortic reconstructive procedures in 1980. Despite reports showing excellent patency rates and minimal complications, widespread acceptance of this graft has not been optimal. Bleeding from needle holes at the proximal aortic-PTFE anastomosis has caused particular concern. In addition, because the PTFE is comparatively more rigid than the Dacron material it has a tendency to kink or "buckle" anteriorly due to displacement by the oversewn distal aorta. This paper describes the creation of an everted cuff of PTFE bifurcated graft to prevent aortic suture-line bleeding, and stapling of the distal aortic stump to avoid graft displacement and kinking at the bifurcation.

Aorta, Abdominal↗
PubMed1989

Distal anastomotic intimal hyperplasia: histopathologic character and biogenesis.

Although thrombogenicity of the prosthetic graft, progression of the atherosclerotic disease and distal anastomotic intimal hyperplasia are known etiologic factors of late graft failure, its occurrence is frequently encountered in the late graft occlusion. Forth-two canine PTFE iliofemoral grafts (all with end-to-side distal anastomosis) were studied. Computer digitization revealed that distal anastomotic intimal hyperplasia occurred exclusively at the heel and the toe of the graft and the floor of the host artery. The distal anastomotic intimal hyperplasia was 80-130 cells thick. Light microscopy and transmission electron microscopy revealed a similar architecture of interlamination of cellular elements and extracellular matrix in the hyperplastic cells. Transmission electron microscopy further defined a gradual cell transformation and orientation from the graft to the lumen. The cells near the graft were characterized by a gradual reduction of rough endoplasmic reticulum with a concomitant acquisition of myofilaments, transforming ovoid mesenchymoid cells to slender myofibroblasts. The orientation of cells in distal anastomotic intimal hyperplasia was embodied by random cell distribution at the periphery to a well-organized interlamination of myofibroblasts and extracellular matrix near the lumen. Distal anastomotic intimal hyperplasia is a biologic entity with active cellular and subcellular events. Its biogenesis appears to be influenced by the hemodynamics of blood flow at the distal anastomosis.

Animals↗
PubMed1989

Obturator bypass with nonreversed translocated saphenous vein.

Obturator bypasses with nonreversed translocated saphenous veins were performed in two patients with femoral graft infections. There were no deaths, limb loss, or graft occlusions at two and one-half years of follow-up in the first case and one and one-half years of follow-up in the second case. The nonreversed translocated saphenous vein is a versatile graft that allows for extraanatomic autogenous reconstruction in the face of infection. In both cases, small-caliber distal saphenous veins precluded performing reversed saphenous vein grafts.

Blood Vessel Prosthesis↗
PubMed1989

Adaptability of endothelial orientation to blood flow dynamics--a morphologic analysis.

Vascular endothelium has a certain specificity in its anatomical orientation. The long axis of the endothelial cell and the shingle effect of cell process overlapping is always oriented parallel to the direction of blood flow. To determine whether this specific anatomical orientation would be maintained when the direction of blood flow was altered, twenty ilio-femoral vein segments and twenty vascular patches of carotid artery and jugular vein were studied. Valvulotomised ilio-femoral vein segments (n = 20) were interposed into adjacent arteries in a non-reversed fashion (the direction blood flow is reversed to the cell process overlapping). One centimeter-square carotid artery and jugular vein patches (n = 20) were rotated 90 degrees (endothelial cell orientation is perpendicular to the direction of blood flow). Reversal of endothelial cell overlapping to complement the complete reversal of the direction of blood flow exists in the vein graft through re-endothelialisation and endothelial reorientation. The process of endothelial reversal occurred in stages (endothelial cell process retraction, interdigitation, complete reversal) and was completed within 8-16 days. In the vascular patch, endothelial re-orientation occurred in 8 days through cell re-orientation and replacement. Mitosis was not encountered in either study. This report highlights certain functions and the adaptive capability of endothelial cells to complement the direction of blood flow.

Adaptation, Physiological↗
PubMed1988

Distal anastomotic intimal hyperplasia: biogenesis and etiology.

Anastomotic intimal hyperplasia occurred exclusively at the heel and the toe plus the floor of the distal end-to-side anastomosis of canine autologous femoro-femoral bypass (n = 14) and not in the end-to-end carotid or femoral interposition graft (n = 14). The occurrence of anastomotic intimal hyperplasia in the absence of compliance mismatch in an autologous bypass suggests that the geometry of the end-to-side anastomosis is primarily responsible for intimal hyperplasia formation. It is believed that because an end-to-side distal anastomosis is not a natural occurrence it is conductive to turbulent flow. The latter causes endothelial injury which in turn allows platelet growth factor to incite subendothelial myoblasts in extracellular matrix synthesis and intimal hyperplasia formation. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) identify myofibroblasts and fibrocollagenous matrix as the dominant cellular and extracellular substances in anastomotic intimal hyperplasia.

Anastomosis, Surgical↗
PubMed1988

Nonreversed translocated saphenous vein bypass for arterial trauma.

Nonreversed translocated saphenous vein (NTSV) bypasses were performed for 17 acute arterial injuries. The technique involved controlling hemorrhage, inserting indwelling shunts, perfusing the harvested saphenous vein with papaverine solution, placing the vein in a nonreversed orientation over the shunt, performing valvulotomy under arterial pressure with a modified Mills' valvulotome and completing the distal anastomosis just before removing the shunt. Followup ranged from 2 to 36 months. There were no graft occlusions. The advantages of using NTSV graft for reconstruction of arterial injuries include autogenous reconstruction, reduced size discrepancy between graft and artery at both the proximal and distal anastomosis, improved hemodynamics when spasm compromises distal runoff, and increased vein utilization. NTSV provides increased versatility with both large and small vessel trauma and may improve patency rates.

Arteries↗
PubMed1986

Vascular anastomoses with laser energy.

Laser-assisted arterial and venous anastomoses are now feasible. A microscope-guided CO2 laser was used to deliver 60 to 100 mW to anastomose end to end 44 rabbit carotid arteries (1.5 to 2.0 mm) and 27 rabbit vena cavae (4 to 6 mm). These were compared with control arteries repaired with interrupted suture technique. Anastomoses were examined from between 24 hours and 19 weeks. Laser carotid anastomoses yielded 93% patency (41 of 44) and 9% aneurysms (4 of 44), whereas hand-sewn carotid anastomoses produced 91% patency (40 of 44) and no aneurysms. In the vena cava, 26 of 27 laser anastomoses were patent (96%) compared with 19 of 20 (95%) sutured controls. Venous aneurysmal dilatation was seen in 2 of 27 laser (7%) and in 3 of 20 (15%) hand-sewn anastomoses. Histologic examination of laser-assisted anastomoses showed local full-thickness thermal injury. Repair was by fibroblast and myofibroblast proliferation, and luminal cell coverage was complete by 14 days in both laser and sutured repairs. Laser arterial and venous anastomoses are attractive because of their simplicity and rapidity of performance. Their patency is comparable to sutured anastomoses, but arterial aneurysms remain a hazard despite use of extremely low laser energy.

Animals↗
PubMed1986

Ruptured abdominal aortic aneurysm presenting as symptomatic inguinal mass: report of six cases.

Six elderly male patients (mean age, 73 years; range, 66 to 78 years) were admitted with groin masses caused by ruptured abdominal aortic aneurysms. A palpable abdominal mass was present in 33%. All patients eventually underwent abdominal aortic aneurysmectomy with a resultant mortality rate of 50%. Delayed diagnosis, preoperative hypotension, advanced age, poor nutritional status, and excessive intraoperative blood loss were factors contributing to this high mortality rate. In this unusual clinical presentation of ruptured abdominal aortic aneurysm, a high index of suspicion by the emergency room staff and prompt surgical intervention are mandatory to improve mortality rates. The anatomy of the retroperitoneal space and the phylogenetic development of a channel between the scrotum and the kidney are important factors in the development of this symptom complex.

Aged↗
PubMed1985

Effects of papaverine on smooth muscle cell morphology and vein graft preparation.

Venous injury following mechanical distension and its late sequelae were studied in a canine model. Jugular vein segments distended without and with papaverine (60 mg/100 ml) were compared with nondistended vein segments after they had been placed into the arterial circulation for 1 to 12 months. Arteriography showed no significant statistical discrepancy in luminal diameter of the three vein segments. Complete reendothelialization had occurred in all vein grafts at the time of harvesting. Similar histocytologic features existed in the nondistended segments and in the portion distended with human plasma protein fraction (Plasmanate) plus papaverine (150 to 300 mm Hg). The intimal-medial hyperplasia was characterized by an increase in fibrocellular layers with an elaboration of vasa vasorum. Conversely, collagen and extracellular matrix replaced the myocyte, producing medial fibrosis in vein mechanically distended with Plasmanate alone. Papaverine prevented mechanical stimulation of smooth muscle cells to overproduce extracellular connective tissue elements. Mechanical stretching of intimal and medial myocytes induced fibrogenesis and fibroplasia. Papaverine is useful in vein preparation; it protects the endothelium and smooth muscle cells in the intima and media and prevents leukocyte infiltration and medial fibrosis.

Animals↗