Vein Wall Injury Research Articles

Angioscopic evaluation of valvular disruption during in situ saphenous vein bypass.

Several valvulotomes are currently available to achieve valvular disruption; however, studies comparing the efficacy of these endoluminal instruments are lacking. This prospective study evaluates the efficacy and safety of the three most commonly employed valve cutters: the Hall, LeMaitre, and Mills valvulotomes. A total of 30 in situ greater saphenous vein bypass grafts were included in this investigation. Valvular disruption was attempted with either the LeMaitre (11 cases), Hall (12 cases), or Mills (7 cases) valvulotomes. Subsequently, angioscopy was employed to assess the completeness of valvulotomy and to identify vein wall injury. Incomplete disruption of one or more valve complexes was identified in 2 of 12 (17%) grafts in the Hall group, 10 of 11 (91%) grafts in the LeMaitre group, and 0 of 7 grafts in the Mills group (p < 0.01). Intact valve cusps were noted in 2 of 36 (5.5%) valves, 31 of 42 (74%) valves, and 0 of 38 valves after valvulotomy with the Hall, LeMaitre, and Mills instruments, respectively (p < 0.01). A total of three valvulotome-related injuries occurred; two injuries were noted in conjunction with the Hall instrument, one was associated with the Mills valvulotome, and no injuries were detected after use of the LeMaitre instrument (p = 0.33). These data demonstrated a significantly increased incidence of retained valve cusps when the LeMaitre valvulotome was used. No significant difference in the rate of vein wall injury was noted in the three groups. Thus this study suggests that the LeMaitre instrument is not as effective as either the Hall or Mills valvulotomes for achieving valvular disruption.

The Use of Dihydroergotamine and Heparin in the Prophylaxis of Deep Venous Thrombosis

Three factors leading to the development of postoperative deep venous thrombosis (DVT) are the hypercoagulable state, stasis, and vein wall injury, which occur in patients undergoing surgical procedures. Vein wall injury is thought to occur as a smooth muscle response to surgical trauma in veins distant from the operative site. Heparin and dihydroergotamine (DHE) were combined in an attempt to decrease the hypercoagulable factor and minimize stasis. We believe that by maintaining venous smooth muscle tone, the degree of endothelial damage is also diminished. Low-dose heparin acts through its effect of factor Xa and activation of antithrombin III; DHE selectively increases venous smooth muscle tone to accelerate venous blood flow velocity and minimize venous pooling. The European experience with combination DHE-heparin prophylaxis shows that this combination is more effective than either agent alone, and studies on orthopedic patients have shown that DHE/5,000 is effective in preventing postoperative DVT in this high-risk group. In the US, the Multicenter Trial evaluated postoperative DVT in general surgical patients. The combination of DHE/5,000 was statistically more effective in the prophylaxis of postoperative DVT than placebo (p = 0.0011). The interim results of an ongoing Multicenter Trial on the prophylaxis of postoperative DVT in patients undergoing total hip replacement indicate that DHE/5000 has significant prophylactic efficacy compared to placebo. It is proposed that the mechanism of action of the DHE-heparin combination is synergistic, since all 3 limbs of Virchow's triad are potentially affected.

Prophylactic efficacy of low-dose dihydroergotamine and heparin in postoperative deep venous thrombosis following intra-abdominal operations

Postoperative pulmonary embolism continues to be a problem in patient care, especially in high-risk patients. This study was designed to evaluate a combined pharmacologic approach to the prophylaxis of postoperative deep venous thrombosis (DVT) by mediating at least two and probably three of Virchow's predisposing factors. Patients 40 years of age and older undergoing operations greater than 45 minutes under general anesthesia were placed in one of five treatment groups and studied by a prospective randomized, double-blind protocol. Study drugs were the following: (1) 0.5 mg of dihydroergotamine plus 5000 IU of sodium heparin (DHE 5000), (2) 0.5 mg DHE plus 2500 IU heparin (DHE 2500), (3) 5000 IU of HEP (HEP 5000), (4) 0.5 mg of DHE (DHE 0.5), and (5) a placebo. Study medications were administered 2 hours preoperatively and continuously thereafter every 12 hours postoperatively subcutaneously in the anterior abdominal wall for 5 to 7 days or until a positive radiofibrinogen uptake test (RFUT). The RFUT was performed according to standardized technique and was used to establish the presence or absence of DVT. This report is an analysis of the major subgroup of patients undergoing intra-abdominal operations. Results showed a highly statistically significant prophylactic benefit from DHE 5000 compared with the placebo (p < 0.003) and all other treatment groups (p < 0.05). There was no significant benefit from DHE 2500, HEP 5000 (p > 0.13), and DHE 0.5 (p > 0.3). All patients who entered the study had two or more risk factors for postoperative DVT, and high-risk patients were distributed equally throughout all treatment groups. DHE 5000 maintained its prophylactic benefit in high-risk patients. Evaluation of operative blood loss, postoperative blood loss, hematomas (wound or injection site), hematuria, postoperative hemoglobin difference, and adverse reactions revealed no significant difference between the study medications and the placebo. It is proposed that DHE 5000 has a synergistic prophylactic effect by mediating all three limbs of Virchow's triad: hypercoagulability (heparin), stasis (DHE), and vein wall injury secondary to venodilatation (DHE). DHE 5000 is recommended for patients at high risk of developing postoperative DVT and pulmonary embolism; however, it should be avoided in patients with acute myocardial infarction, sepsis, and sustained hypotension.

Vascular complications following cancer surgery of the pelvis and groin.

Ten vascular complications associated with radical cancer surgery of the pelvis and groin in 9 patients are reported. Case analyses and illustrative vascular studies are presented to stress early recognition and treatment which lead to a satisfactory outcome. Seven complications were venous in origin; 3 were arterial. Obvious vessel injury at the primary operation occurred in only 2 instances. In 5 cases, immediate thrombectomy, thromboendarterectomy, or bypass grafting resulted in relief of symptoms. Three instances of venous thrombosis were treated conservatively; 2 made a satisfactory recovery, but one died of pulmonary embolism 4 days after direct vein wall injury at operation. In another case, direct lysis of cicatrix around a narrowed femoral vein resulted in partial resolution of lower leg edema 2 1/2 years after total pelvic exenteration.