No abstract

In this model, arteries and VG responded to flow reduction by wall thickening, but the mechanism differed. Arteries underwent medial remodeling, lumen caliber reduction, and shear stress normalization, whereas VG responded by an upward modulation of the proliferative response that follows graft placement. These data support a primary role for tangential stress and a secondary role for shear stress in determination of VG dimensions.

No abstract

Angiography, angioscopy, and duplex scanning have each been advocated for intraoperative assessment of in situ saphenous vein grafts. We compared these three modalities during operation in a prospective, blinded study during the construction of 20 femoral-infragenicular in situ saphenous vein grafts. Bach modality was used and interpreted by a surgeon blinded to the results of the other studies. Abnormalities requiring intervention were defined as (1) patent vein side branches, (2) residual valve cusps, and (3) anastomotic stenoses > 30%. Criteria, specific to the modality, corresponding to each category were prospectively defined. Fourteen residual valve cusps, 49 patent vein branches, and 6 anastomotic stenoses were suggested by at least one modality. Nine residual valve cusps, 32 patent vein branches, and no anastomotic stenoses were actually found (and corrected) by direct inspection. Sensitivityofdetecting patent side branches for angiography, duplex scanning, and angioscopy was 44%, 12%, and 66%, respectively. Both angiography and angioscopy were significandy more sensitive than duplex scanning for detection ofunligated side branches (p < 0.01). Sensitivity ofdetecting residual valve cusps was 22% (angiography), 11% (duplex scanning), and 100% (angioscopy). Angioscopy was significandy more sensitive than either duplex scanning or angiography in detection of residual valve cusps Cl < 0.01). Since no anastomotic stenoses were confirmed, the false-positive rates for stenosis detection were 20% for angiography, 10% for duplex scanning, and 0% for angioscopy. Time requirement was 17 to 20 minutes and did not differ among the three modalities. No stenosis or arteriovenous fistula has been detected in any graft by postoperative duplex surveillance (mean, 10-month follow-up). Angiography and angioscopy were superior to duplex scanning for detecting patent vein branches. Angiography or duplex scanning alone would have missed > 75% of residual valve cusps. These results suggest that angioscopy is the preferred method for intraoper-. ative in situ vein graft evaluation.

Vascular malformations of the tongue (hemangiomas, lymphangiomas, AV fistulae, etc.) compromise a significant portion of head and neck angiodysplastic lesions. Complications requiring treatment include bleeding, pain, and difficulties related to increased tongue volume. Treatment modalities have included embolization, excision, cryotherapy, sclerosis, radiation, and chemotherapy. The more aggressive therapies often result in major functional disability to loss of lingual tissue. A series of nine patients has been treated for one or more of the complications of lingual vascular malformations with either argon of Nd:YAG laser photocoagulation. The therapeutic objective was provision of symptomatic relief with conservation of functioning lingual tissue. Results have varied from good to excellent with markedly decreased bleeding frequency as well as reduction in lesion size. No serious complications, such as bleeding or invasive infection, have been noted. Laser phototherapy is beneficial in the palliation of selected benign lingual vascular malformations.