A prospective evaluation of arterial intimal injuries in an experimental model

The management of arterial intimal defects remains controversial because of uncertainty concerning their natural history. We developed an experimental canine model to prospectively evaluate posterior wall intimal flaps in the superficial femoral artery. Arterial intimal flaps were constructed in 20 anesthetized dogs (40 arteries) and evaluated by arteriography, and angioscopy, and intravascular ultrasound. Postoperative patency rates at 1 (n = 20) and 3 weeks (n = 20) were compared with a control group of ten animals (n = 20, arteriotomy without intimal flap). Acute thromboses occurred in five experimental arteries with thromboses of eight additional experimental arteries at followup. Control patency was 100%, while experimental group patencies were 75% (p less than 0.05) at 1 week and 60% (p less than 0.009) at 3 weeks. All thrombosed arteries had intimal flaps with greater than 75% luminal stenosis. We conclude that intimal injuries cause arterial thromboses acutely and during subsequent followup. Intimal flaps with stenosis greater than 75% as determined arteriographically are at greatest risk for thrombosis. Angioscopy and intravascular ultrasound characterize arterial intimal defects and may delineate injuries requiring surgical or endovascular repair.     

The natural history of intimal flaps caused by angioscopy

This study tried to determine the natural history of angioscopy-induced arterial intimal flaps as assessed by video angioscopy, light and transmission electron microscopy. Eight mongrel dogs were anesthetized and bilateral femoral and carotid arteries surgically exposed. A 3.0 mm American Edwards angioscope was inserted into each artery and passed vigorously until an intimal flap was visualized by angioscopy. The location of intimal flaps was externally marked with 6–0 polypropylene adventitial sutures. Animals were then recovered and follow-up angioscopy performed at one, two, three, and four week intervals. Following repeat angioscopy, all animals were sacrificed and vessels perfusion-fixed in situ with 2.5% glutaraldehyde in 0.1 M sodium cacodylate. A total of 37 intimal injuries were created (immediate, n=10; one week, n=8; two weeks, n=4; three weeks, n=8; four weeks, n=7). No arterial thrombosis occurred following intimal flap formation. Only one of 37 (2.7%) lesions progressed to a hemodynamically significant stenosis. Histology of immediate lesions demonstrated deep intimal fractures extending into the tunica media. Complete healing of intimal flaps was observed by follow-up angioscopy in zero of eight lesions by one week, zero of four lesions by two weeks, one of eight lesions by three weeks, and four of seven lesions by four weeks (p=0.02). Light and electron microscopy confirmed the angioscopic intimal fractures and regrowth of denuded endothelium. Conclusion: follow-up angioscopy and microscopy one month after angioscopy-induced arterial intimal trauma demonstrated a significant trend towards complete endothelial healing.Presented at the 16th Annual Meeting of the Peripheral Vascular Surgery Society, June 2, 1991, Boston, Massachusetts.     

Saratin, an inhibitor of von Willebrand factor-dependent platelet adhesion, decreases platelet aggregation and intimal hyperplasia in a rat carotid endarterectomy model.

PURPOSE: Post-carotid endarterectomy, thrombosis, and intimal hyperplasia may be decreased by the inhibition of platelet adhesion and activation. In this study, a novel agent, saratin, was used to inhibit platelet-to-collagen adhesion in a rat carotid endarterectomy model. Saratin is a recombinant protein isolated from the saliva of the medicinal leech Hirudo medicinalis, which is thought to act by binding to collagen, and inhibits von Willebrand factor-collagen interaction under conditions of increased shear and therefore, the adherence and activation of platelets at the vessel wall. Saratin has the advantage of being a nonsystemic, site-specific topical application. METHODS: A rat carotid endarterectomy model was used in which an open technique with arteriotomy and intimectomy was used. Saratin was applied to the endarterectomized surface of the carotid artery before arterial closure. End point measurements included platelet adhesion, thrombosis rate, intimal hyperplasia development, bleeding times, and platelet counts. Electron micrographs of carotid arteries were used for quantitative analysis of platelet aggregation and platelet counts. Intimal hyperplasia and thrombosis were assessed with computer-assisted morphometric analysis of elastin-stained carotid artery sections with direct measurement of the intimal hyperplasia area. RESULTS: The topical application of saratin significantly decreased platelet adhesion compared with controls at 3 hours after carotid endarterectomy (64 +/- 17 vs 155 +/- 33 platelets per grid, P = .05), and 24 hours after carotid endarterectomy (35 +/- 11 vs 149 +/- 37 platelets per grid, P = .0110), respectively. A percent luminal stenosis, as a measure of intimal hyperplasia, was significantly decreased with saratin application compared with controls (10.9% +/- 1.8% vs 29.8% +/- 6.8%, P = .0042). This decrease in intimal hyperplasia formation correlated with the inhibition of platelet adhesion. Thirty-three percent of control arteries were found to be thrombosed 2 weeks after carotid endarterectomy compared with a 0% thrombosis rate in the saratin-treated group (P = .0156). No increased bleeding was encountered along the arterial suture line in the saratin group. Bleeding times and systemic platelet counts were not found to change significantly in the saratin-treated rats compared with control rats at 3 and 24 hours after endarterectomy. CONCLUSION: Saratin significantly decreased platelet adhesion, intimal hyperplasia, luminal stenosis, and thrombosis after carotid endarterectomy in rats. Saratin did not increase suture line bleeding or bleeding times, and did not decrease platelet counts. Saratin may serve as a topical agent to be used for the site-specific inhibition of thrombosis and intimal hyperplasia after vascular manipulation.     

The fate of unrepaired minor technical defects detected by intraoperative ultrasonography during carotid endarterectomy

This report describes the natural history of unrepaired minor technical defects detected by intraoperative B-mode ultrasonography during carotid endarterectomy. Intraoperative ultrasonography was used to assess the technical adequacy of 80 carotid endarterectomies. Sixty-two arteries were normal on intraoperative ultrasound examination, whereas the remaining 18 arteries had a total of 21 minor residual technical defects. The 21 minor defects consisted of four internal carotid artery lesions, nine common carotid artery lesions, and eight external carotid artery lesions, 19 had 1 to 3 mm intimal flaps, and two had small stenoses. Sixteen of the 19 intimal flaps resolved before the first postoperative ultrasound study. These arteries had normal examination results, which indicated that these intimal flaps had healed. The two stenoses detected intraoperatively could not be detected by postoperative carotid duplex scanning at 1 month follow-up. No statistically significant relationship was found between the presence of a minor residual defect on intraoperative ultrasonography and the subsequent development of recurrent stenosis or occlusion in any of the arteries assessed. These data suggest that certain minor technical defects in the carotid artery that were detected by intraoperative ultrasonography are benign and may not require repeat exploration of the carotid artery for repair.     

The CO2 laser as an intraluminal repair tool

The CO2 laser can weld vessels together and vaporize plaque. This study evaluates its use as an intraluminal reparative tool. In 17 dogs, a 1-cm circumferential intimectomy with a 1-mm distal intimal flap was performed in both carotids. In each dog, one carotid (CON, control) underwent suture flap repair. On the contralateral side (LR, laser repair), the flap was tacked with 20 250-mW 1-sec pulses and the denuded medium was g-lased for 90 sec (250 mW continuous). Animals were randomized into five groups and sacrificed on the day of surgery (Group I, n = 3), at 3 days (Group II, n = 3), at 1 week (Group III, n = 4), at 2 weeks (Group IV, n = 4), or at 4 weeks (Group V, n = 3). Vessel patencies were 88.2 and 82.4% for CON and LR, respectively. Flap repair appeared similar. No aneurysms were noted. Histology revealed a relative absence of platelet adherence to the g-lased surfaces in Groups I and II when compared to that of mechanical methods (CON). The ratio of the thickness of the regenerated surface to the total wall thickness demonstrated hyperplasia in LR vessels (0.54 +/- 0.12) when compared to that in CON (0.30 +/- 0.15) at 2 and 4 weeks (ANOVA, P less than 0.001). Coverage with endothelial-like cells appeared complete at 4 weeks in both methods. The CO2 laser can effectively repair intimal flaps. However, our results demonstrate a significant increase in medial hyperplasia following g-lasing even in the face of minimal early platelet adherence. This may prove detrimental to the long-term patency of intraluminal CO2 laser-treated vessels.     

Renal artery intimal flaps after blunt trauma: indications for nonoperative therapy

After sustaining blunt abdominal trauma, two patients were found to have intimal flaps in extrahilar renal arteries without thrombosis. These renal artery injuries were observed without surgical repair because of severe concomitant multiple organ trauma. Continued patency of the renal arteries was confirmed by sequential renal scans or arteriograms. To decrease the risk of morbidity and death after blunt renovascular trauma, a patent artery with an intimal flap may be observed. Mandatory urgent repair is reserved for patients with bilateral renal injuries or for patients with a solitary kidney. Should symptomatic renal infarction or hypertension develop, delayed renal artery repair or nephrectomy is indicated.     

Endovascular management of arterial intimal defects: an experimental comparison by arteriography, angioscopy, and intravascular ultrasonography

To determine the feasibility of the endovascular management of intimal defects while comparing the accuracy of arteriography with angioscopy and intravascular ultrasonography, we developed an in vivo model of arterial intimal flaps. In 10 superficial femoral arteries of five anesthetized mongrel dogs, intimal flaps were constructed and then imaged by arteriography, angioscopy, and intravascular ultrasound. A flexible microbiopsy forceps was used to remove each intimal flap under angioscopic guidance. Arteriographic lumen diameters were measured and cross-sectional areas calculated. Corresponding measurements by angioscopy and intravascular ultrasound with reduction in luminal area at the flap were obtained by use of computerized planimetry. Uniplanar arteriography identified 60% (6/10) of the intimal flaps, whereas angioscopy and intravascular ultrasound demonstrated 100%. Lumen diameter (in millimeters) measured by arteriography (3.4 +/- 0.6) correlated significantly with measurements by angioscopy (3.5 +/- 0.5, r = 0.77) and intravascular ultrasound (3.5 +/- 0.6, r = 0.96). Similarly, lumen area (square millimeters) by arteriography (9.2 +/- 2.9) correlated with measurements by angioscopy (8.9 +/- 2.2, r = 0.82) and intravascular ultrasound (8.6 +/- 2.7, r = 0.91). Reduction in lumen area by the flap by angioscopy (37 +/- 7%) and intravascular ultrasound (33 +/- 8%) also correlated significantly (r = 0.72). The intimal flaps were removed successfully in all 10 arteries as confirmed by arteriography, angioscopy, and intravascular ultrasound. We conclude that the endovascular management of intimal defects is possible. Additionally, angioscopy and intravascular ultrasound accurately evaluate lumen diameter and area while providing direct assessment of intimal defects.     

Natural history, duplex characteristics, and histopathologic correlation of arterial injuries in a canine model.

The treatment of patients with penetrating extremity trauma in proximity to major arteries as well as the nonoperative treatment of clinically occult arterial injuries remain controversial. Duplex ultrasonography (DUS) has recently been advocated in this setting. We therefore studied experimentally induced arterial injuries in dogs to correlate the natural history, duplex findings, and histopathologic condition of different injuries and to help define criteria for operation. Fifty-two canine femoral and carotid arteries were randomized to have surgically created intimal flaps (n = 15), crush injuries (n = 15), or lacerations (n = 15) or to be controls (n = 7). An experienced sonographer, blinded to the presence or type of injury, evaluated the vessels every 10 days for 1 month. Histopathologic study was performed 1 month after injury when the arteries were retrieved. The sensitivity (96.5%), specificity (86.4%), and accuracy (95.1%) of DUS in evaluating arterial injuries at 1 month correlated well with histopathologic evaluation. All arteries subjected to crush injuries showed abnormal duplex findings. These findings correlated well with the histologic picture of severe injury (arterial wall thickness = 2.72 x +/- 0.23 x control; intramural hemorrhage, 93%; mural thrombus, 60%). DUS and histologic study revealed healing of intimal flaps in 27% of the arteries. Other intimal flaps deteriorated (stenoses, 47%; dilation, 13%; occlusion, 13%). Most lacerations (86%) revealed duplex evidence of healing within 10 days of injury. This was confirmed by histologic study at 1 month in 73% of lacerated arteries. This study confirms the accuracy of DUS in diagnosing various arterial injuries and shows that the natural history of these injuries varies with the mechanism of injury.(ABSTRACT TRUNCATED AT 250 WORDS)     

Selective management of nonocclusive arterial injuries

Between 1978 and 1988, 50 patients were demonstrated arteriographically to have 61 nonocclusive arterial injuries (44 major arteries, 17 minor arteries). The 61 injuries consisted of 19 intimal defects, 4 intimal flaps, 26 pseudoaneurysms, 2 arterial stenoses, and 10 arteriovenous fistulas. End-organ ischemia or ongoing hemorrhage were not present. All patients were treated nonoperatively. At 1 to 12 weeks after the injury, 30 arterial injuries (24 major, 6 minor) were studied by repeated arteriography. Resolution, improvement, or stabilization of the injury occurred in 21 (87%) major artery injuries. Progression occurred in the remaining 3 injuries, including 1 patient who underwent subsequent successful repair. Twenty-one injuries were followed up without repeated arteriography. Delayed arterial thrombosis, hemorrhage, or ischemia did not develop, and no patient required operative management. Eight of 10 additional arterial injuries had successful percutaneous embolization at the time of repeated arteriography. The overwhelming majority of small arterial injuries or intimal fractures do not lead to vascular complications if managed nonoperatively. A routine policy of operative exploration for all such injuries is therefore unwarranted. These injuries are best managed by observation and serial arteriography to document spontaneous healing or progression.     

Detection of arterial defects by real-time ultrasound scanning during vascular surgery: An experimental study

Real-time ultrasound B-mode scanning was used experimentally to detect vascular defects resembling those which might occur in arterial reconstructive surgery. The lesions established were arterial strictures, subintimal hematomas, intimal flaps, and thrombi attached to the arterial wall. All types of lesions were readily identified by direct contact ultrasonography. Ultrasonography was evaluated in terms of qualitative and quantitative assessment. Qualitatively, 68% of 1 × 5-mm flaps and 100% of all larger flaps were detected. There were no false positive ultrasound diagnoses in the interpretation of sonograms from normal arterial segments. Quantitatively, ultrasonic estimation of flap size correlated with actual flap dimensions with a coefficient of correlation of 0.84 (P < 0.001). This study indicates that operative ultrasound to detect relatively small vascular defects at arterial operative sites is a feasible procedure which should be evaluated in clinical application.     

Dysvascular lower extremity reconstruction using free flaps with a "Y" configuration of the arterial pedicle

For patients with a dysvascular lower extremity, free flaps have been transferred by end-to-side anastomosis, in order to maintain peripheral circulation. For such patients, the authors have applied free flap transfers with a "Y" configuration of the arterial pedicle. Eight free flaps with a Y configuration of the arterial pedicle were used in seven patients: latissimus dorsi musculocutaneous flaps in six, and scapular flaps in two. For the former, flaps were harvested with the subscapular and circumflex scapular arteries forming a Y pedicle in three cases, and with the thoracodorsal artery and the branch of the serratus anterior muscle in three. For the scapular flap transfers, the flap was harvested with the subscapular and thoracodorsal arteries forming a Y pedicle in one case, and with the circumflex scapular artery and the descending branch in the other. This procedure was performed for single-artery extremities in two cases. One developed arterial thrombosis of the branch to the foot, but removal of the thrombus and reanastomosis resulted in peripheral blood circulation being maintained. Eventually, all flaps survived. This procedure is indicated in patients with lower-leg reconstruction, especially with vascular disease.     

手指皮瓣分类和急诊修复

目的选择应用伤指本体皮瓣和邻指皮瓣重建指端缺损的方式,总结临床应用疗效。方法2001年8月~2005年6月,收治108例112指手外伤,其中男68例71指,女40例41指;年龄16~63岁。损伤原因:均为切削、挤压和撕脱伤,伤后2 h内手术。采取9种皮瓣,对手指指端的急性软组织损伤缺损进行修复.将皮瓣分为两大类:①指动脉主干血管营养皮瓣,包括:指神经血管束V-Y岛状提升瓣,指动脉逆行皮瓣,改良M oberg皮瓣和指神经血管束蒂双翼皮瓣,皮瓣范围2.0 cm×1.5 cm;②指动脉侧支血管营养皮瓣,包括:拇指尺背侧动脉逆行皮瓣,皮瓣范围:1.5cm×1.5 cm~3.0 cm×2.5 cm,指动脉背侧支逆行皮瓣,皮瓣范围1.7 cm×1.0 cm~4.5 cm×3.0 cm;指掌横支皮瓣,其皮瓣范围:2.0 cm×1.0 cm~2.5 cm×2.0 cm;食指背岛状皮瓣和手指局部皮瓣。结果术后3指坏死,3指浅表性坏死。其余106指移位完全成活。术后随访2周~8个月,皮瓣两点辨别觉5~10 mm,指活动良好,外观令人满意。结论选择上述皮瓣可修复所有的末节指端软组织缺损创面,并获得良好的修复外形。     

Turbulence occurring after carotid bifurcation endarterectomy: a harbinger of residual and recurrent carotid stenosis

The goal of carotid endarterectomy is to remove an obstructing or embologenic lesion and reconstruct a durable arterial segment free of flow abnormality. The technical adequacy of 250 endarterectomy sites in 235 patients was assessed at operation by pulsed Doppler spectral analysis and arteriography and was correlated with postoperative patency, the incidence of residual and recurrent stenosis, and clinical outcome. Duplex scanning was used after operation to categorize disease severity. At operation, 10 patients (4%) had angiographic and Doppler flow abnormalities identified in the internal carotid artery. Vessel exploration identified intimal flaps, platelet aggregation, or stricture. Residual flow disturbances at the endarterectomy site correlated with perioperative thrombosis and stroke, angiographic abnormalities, primary closure of the arteriotomy, and a postoperative duplex scan consistent with stenosis. In 175 patients (182 sites) with normal arterial flow after carotid bifurcation endarterectomy, no thrombotic events occurred and the incidence of recurrent stenosis (life-table analysis) was zero at 3 months, 5% at 1 year, and 9% at 2 years. The incidence of occlusion and recurrent stenosis was increased (8% at 3 months, 18% at 1 year, and 21% at 2 years) in 68 arteries with residual flow disturbance identified at operation. Assessment of endarterectomy sites for turbulence identifies anatomic lesions that threaten patency and increase the incidence of residual and recurrent stenosis.     

Free radical attenuation prevents thrombosis and enables photochemical inhibition of vein graft intimal hyperplasia

OBJECTIVE: Photodynamic therapy (PDT) inhibits post-interventional stenosis in balloon-injured arteries, but causes thrombosis when applied to vein grafts. This may result from added free radicals produced during the hypoxia-reperfusion injury of vein graft implantation. The purposes of this study were to determine whether a free radical scavenger could inhibit vein graft thrombosis, enabling PDT to inhibit intimal hyperplasia; and to investigate the role of neutrophils, also a source of radicals, in this setting. METHODS: Jugular vein bypass grafts of the common carotid artery were performed in rats. PDT was administered in situ to the vein graft and artery in the presence or absence of deferoxamine (DFX), an OH- scavenger. RESULTS: PDT alone induced thrombosis in all untreated vein grafts. DFX administration or inhibition of neutrophil adhesion to the graft prevented PDT-induced vein graft thrombosis. Moreover, DFX given together with PDT significantly decreased vein graft intimal hyperplasia (0.010 mm2 +/- 0.005 mm2; P<.002) as compared with DFX alone (0.113 mm2 +/- 0.009 mm2) or untreated control animals (0.112 +/- 0.007 mm2). CONCLUSIONS: OH- radicals and neutrophils both have key roles in PDT-induced vein graft thrombosis. By inhibiting free radical production or neutrophil adhesion to the graft, adequate PDT can be administered for successful inhibition of vein graft intimal hyperplasia.     

Nonoperative observation of clinically occult arterial injuries: a prospective evaluation

Forty-seven patients with 50 clinically occult injuries of major arteries were studied prospectively to determine the natural history of these lesions and the safety of nonoperative management. Penetrating trauma was the predominant mechanism and lower extremity arteries were most commonly involved. The morphology of these arterial injuries included 22 cases of intimal flaps, 21 cases of segmental arterial narrowing, 6 pseudoaneurysms, and 1 acute arteriovenous fistula. There was one death as a result of unrelated causes and another three injuries operated on immediately after arteriographic diagnosis. The remaining 46 injuries were followed up nonoperatively by serial arteriography (39) or clinical examination (7) during a mean interval of 3.1 months (range, 3 days to 27 months). Complete resolution was documented for 29 injuries (63%), whereas 3 improved, 9 remained unchanged, and 5 worsened during the period of follow-up. All worsened cases involved small or occult pseudoaneurysms that subsequently enlarged and then underwent immediate surgical repair without subsequent morbidity. Because 89% of the followed injuries never required surgery, nonoperative observation appears to be a safe and effective management option for clinically occult arterial injuries.     

应用前臂游离皮瓣折叠法修复大型腭部洞穿性缺损

目的 探讨大型腭部洞穿性缺损修复的方法.方法 2003年至2006年,我们应用前臂游离皮瓣折叠法为7例患者进行了腭部洞穿性缺损修复,共使用皮瓣8块,其中前臂游离皮瓣7块,胸大肌岛状瓣1块.结果 除1例前臂游离皮瓣因动脉栓塞失败外,其余组织瓣完全成活,再造腭部形态良好.患者可经口腔正常进食,并进行基本正常的语言交流.结论 利用前臂游离皮瓣折叠法进行大型腭部洞穿性缺损的修复,是一种有效可行的方法.     

指端缺损的急诊岛状皮瓣修复

目的介绍8种指岛状皮瓣对指端缺损创面的修复,并探讨其相关手术适应证。方法应用指神经血管束VY岛状推进皮瓣、拇指尺背侧动脉逆行皮瓣、指动脉背侧支逆行皮瓣、改良Moberg皮瓣、指动脉逆行皮瓣、Hueston皮瓣、指筋膜脂肪翻转瓣、指总神经血管束蒂双翼皮瓣等8种皮瓣修复79例82指指端缺损。结果手指外形和功能均取得了令人满意的结果。结论这些指岛状皮瓣适宜指端缺损的修复。     

Corrective Hair Restoration Techniques for the Aesthetic Problems of Temperoparietal Flaps

BACKGROUND: Temperoparieto-occipital flaps (Juri flap) and temperoparietal flaps (Elliott) were commonly performed in the previous decades but have fallen out of favor for the most part with the development of follicular unit hair transplantation. Besides high complication rates, these procedures created straight abrupt hairlines in many cases, posterior hair direction, hair density that was disproportionately thick, and blunt temperofrontal angles. OBJECTIVE: Because there are many patients who live with cosmetic deformities created by previous flap procedures, the objective of this article is to present a series of techniques that will restore these patients to normal cosmesis. METHODS: The techniques for amelioration of poor cosmesis secondary to flap procedures are (1) undulating follicular unit grafting anterior to the hairline, (2) removal of 2- to 3-mm cylinders of hair-bearing scalp at the anterior hairline, (3) removal of 2- to 3-mm cylinders of hair-bearing scalp from within the flap itself, and (4) appropriate fusiform excision techniques to create a normal temperofrontal angle. RESULTS: The combination of the aforementioned techniques has restored a very natural cosmesis in patients who have poor aesthetics after flap surgery. CONCLUSION: Many patients exist who have had Juri and Elliott flaps. Although the cosmetic deformities that are created from these flaps are difficult to improve, they can be ameliorated effectively through a series of maneuvers that are described in this article.     

An experimental evaluation of arteriography and imaging ultrasonography in detecting arterial defects at operation

Vascular lesions resembling those which might occur in arterial reconstructive surgery were produced in canine aortas and examined by portable arteriography, serial biplane arteriography, and B-mode real-time ultrasonography. The lesions established were intimal flaps, thrombi, strictures, and intimal defects. The accuracy and sensitivity of imaging ultrasonography was higher than both portable and serial biplane arteriographies for detecting 2 × 5-mm intimal flaps, 5 × 5-mm, intimal flaps and thrombi. There was no difference for aortic segments with strictures. Serial arteriography was more sensitive than portable arteriography for 2 × 5-mm flaps and for thrombi. Sensitivity for intimal defects was higher for both types of arteriographies than for ultrasonography. The specificity for all three procedures was high and without significant difference among them. This experimental study indicates that operative ultrasonography is more precise for detecting intravascular defects than both portable and serial biplane arteriographies. Clinical application and evaluation of this diagnostic procedure is warranted.     

Preservation of endothelial integrity and function in experimental vascular anastomosis with non-penetrating clips

BACKGROUND: Vascular repair with sutures is associated with disruption of the endothelial lining and subsequent thrombus formation on the intraluminal lesions. This experimental study was designed to determine whether the use of non-penetrating clips improved endothelial preservation. METHODS: In ten female pigs, 25-mm arteriotomies were made in both carotid arteries. The arteriotomies were repaired with jugular vein patches. On the left side, the repair was done with 1.4-mm titanium clips, and on the right side with two running 6/0 polypropylene sutures. Next, the aorta was divided and subsequently repaired with 2-mm clips in five of these pigs, and with two running 5/0 polypropylene sutures in the remaining five pigs. Endothelial function was studied at the anastomotic site in the carotid arteries by determination of endothelium-dependent and -independent relaxatory responses. Morphometric examination of the carotid arteries and inspection of the aortic endothelium were performed by means of scanning electron microscopy. RESULTS: Maximal endothelium-dependent relaxation to adenosine 5'-diphosphate was less in sutured than in clipped carotid arteries (P < 0.05), while there was no difference in maximal endothelium-independent relaxation to sodium nitrite. This result in clipped carotid arteries was not accompanied by less intimal hyperplasia. Screening of the aortic anastomotic line showed better preservation of endothelial architecture after clip anastomosis. Mean cross-clamp time for carotid patch repair was significantly less when using clips than with sutures. CONCLUSION: The use of non-penetrating clips for vascular anastomoses preserved endothelial function and structural integrity better than running sutures, although the degree of intimal hyperplasia was similar.