Dean T. Sato

Endoleak after aortic stent graft repair: Diagnosis by color duplex ultrasound scan versus computed tomography scan

PURPOSE The purpose of this study was to compare the accuracy of a color duplex ultrasound scan (CDU) to a computerized axial tomography scan (CT) in the diagnosis of endoleaks after stent graft repair of abdominal aortic aneurysms. METHODS The Endovascular Aneurysm Clinical Trial Core Laboratory records were reviewed from 117 concurrent CDU and CT studies that were performed in 79 patients who were implanted with the Endovascular Technologies stent graft device between December 1995 and January 1997. All of the studies were interpreted by the Core Laboratory as having the presence or the absence of an endoleak or as being indeterminate because of technical factors. Of the 117 videotaped CDU studies available for reexamination, 100 were reassessed for technical adequacy on the basis of the following criteria: a satisfactory imaging of the aneurysm sac and of the stent graft with gray scale, and both color and spectral Doppler scan evaluation for endoleak outside the endograft and within the aneurysm sac. RESULTS Of the 117 studies, 103 CDUs (88%) and 114 CTs (97%) were recorded as having the presence or the absence of an endoleak and 14 CDUs (12%) and 3 CTs (3%) were indeterminate. For the studies that were recorded to have the presence or the absence of an endoleak, the sensitivity, the specificity, the positive and the negative predictive values, and the accuracy of CDUs as compared with CTs were 97%, 74%, 66%, 98%, and 82%, respectively. Of the 100 CDU videotaped studies available for review, the following results were seen: (1) 93 CDUs had satisfactory B-mode images, (2) 76 had satisfactory color Doppler scan images to evaluate for endoleaks, (3) 55 had color Doppler scan assessment of the entire abdominal aortic aneurysm sac for endoleak, and (4) 27 had spectral Doppler scan waveform confirmation of suspected endoleaks. Only 19 CDU studies (19%) with all 4 criteria for complete assessment of endoleak were performed. CONCLUSION Although most of the CDU studies were technically suboptimal, the CDUs reliably identified endoleaks with an excellent sensitivity and a negative predictive value as compared with CT scans.

The natural history of calf vein thrombosis: Lysis of thrombi and development of reflux

PURPOSE Although the fact is well accepted that deep venous thrombosis (DVT) of the iliac, femoral, and popliteal veins can lead to the post-thrombotic (postphlebitic) syndrome, the significance of isolated calf DVT on the development of late venous sequelae and physiologic calf dysfunction is unknown. The purpose of this study was to review the outcome of 58 limbs with isolated calf DVT and report the clinical, physiologic, and imaging results up to 6 years after the onset of DVT. METHODS The study consisted of 58 limbs of 54 patients in whom isolated calf vein DVT was diagnosed between 1990 and 1995. Proximal propagation of clot, lysis of thrombi, and development of symptomatic pulmonary emboli were examined. Of the patients, 28 received anticoagulation therapy, and 26 did not, but they had follow-up with serial duplex scans. At late follow-up 1 to 6 years later (median, 3 years), 23 patients were examined for the post-thrombotic syndrome, and all 23 underwent clinical examination, color-flow duplex scanning, and air plethysmography. RESULTS Proximal propagation of DVT from the calf veins into the popliteal or thigh veins occurred in 2 of 49 cases (4%) within 2 weeks of diagnosis. No patient had clinically overt pulmonary emboli develop regardless of whether anticoagulation therapy was received or not. The most common site for calf DVT was the peroneal vein (71%). Complete lysis of calf thrombi was found in 88% of the cases by 3 months. At 3 years, 95% of the patients were either asymptomatic or mildly symptomatic, and 5% had discoloration of the limb. No ulcers occurred. By air plethysmography, physiologic abnormalities were found in 27% of the cases, which was not significantly different from normal controls. Valvular reflux by duplex scanning of the calf vein segment with DVT was found in 2 of 23 cases (9%). However, reflux in at least one venous segment not involved with DVT was found in 7 of 23 cases (30%), which was higher than, but not statistically different from, normal controls, with reflux occurring in 5 of 26 cases (19%). CONCLUSIONS Isolated calf vein DVT leads to few early complications (ie, clot propagation, pulmonary emboli) and few adverse sequelae at 3 years. The peroneal vein is most commonly involved and should be a part of the routine screening for DVT. Lysis of clot usually occurs by 3 months. Although valvular reflux rarely is found in the affected calf vein at 3 years, reflux may be found in adjacent uninvolved veins in approximately 30% of the cases. The question of whether this will lead to future sequelae, such as ulceration, will require longer follow-up.

Risk factors for venous thromboembolism following prolonged air travel. Coach class thrombosis.

Venous thromboembolism (VTE) in legs and lungs is a potentially life-threatening condition. The incidence of VTE associated with air travel is still unknown, but it may have increased. Most travelers who develop symptoms do so within 24 hours after their flight takes off. Predisposing risk factors may be divided into patient-related and cabin-related factors, both of which are described. It is emphasized that better information and better inflight precautions can minimize these risk factors.

Reflux from Thigh to Calf, the Major Pathology in Chronic Venous Ulcer Disease: Surgery Indicated in the Majority of Patients

The aim of this study was to define the underlying anatomical and pathophysiological conditions in limbs with venous ulcers in order to get information for the most appropriate treatment selection. Ninety-eight limbs (83 patients, 59 men), with active chronic venous ulcers, were analyzed retrospectively and classified according to the CEAP (clinical, etiological, anatomical, and pathophysiological) classification. Duplex-ultrasound was performed in all patients, while air-plethysmography and venography were performed selectively on potential candidates for deep venous reconstruction. Sixty-six ulcers were primary in origin and 32 were secondary. Reflux was present in all limbs except 1. Isolated reflux in 1 system (superficial = 3, deep = 4, perforator = 3) was seen in 10 legs (10%), while incompetence in all 3 systems was seen in 51 legs (52%). Superficial reflux with or without involvement of other systems was seen in 84 legs (86%), 72 legs (73%) had deep reflux with or without involvement of other systems, and incompetent perforator veins were identified in 79 limbs (81%). Axial reflux (continuous reverse flow from the groin region to below knee) was found in 77 limbs (79%). The femoral vein was the single most common deep venous segment in which either reflux or obstruction was found. Axial distribution of disease was found in the majority of cases and no patient had isolated deep venous incompetence below knee. Primary disease was the predominant etiologic cause and reflux was the main pathophysiological finding. Practically all patients were found to have 1 or more sites of reflux or obstruction that could benefit from operative treatment.

Subfascial perforator vein ablation: comparison of open versus endoscopic techniques.

Purpose: To compare the outcomes and complications of open (OSPS) versus endoscopic subfascial perforator surgery (SEPS) for treatment of chronic venous insufficiency. Methods: Data were retrospectively collected on 25 patients who underwent 27 SEPSs from February 1996 to August 1997 and from 22 patients who underwent 29 OSPSs between March 1978 and May 1993. Outcomes were evaluated for postoperative complications, ulcer healing, recurrence, and venous dysfunction scores on the last follow-up for the SEPS group and at 1-year follow-up for the OSPS group. Results: The 2 groups were similar in age, sex, history of previous venous surgery, healed or active ulcers, etiology, deep venous incompetency, pathophysiology, and venous refill times. Eighteen (90%) of 20 active ulcers in the SEPS group healed with recurrences in 5 (28%) limbs at 7.5 ± 5.4-month follow-up. All 19 ulcers in the OSPS group healed, with recurrences in 13 (68%) limbs at 35 ± 35-month follow-up. Clinical venous dysfunction scores showed significant improvement following SEPS (10.0 ± 3.6 to 5.4 ± 4.1, p < 0.001) and OSPS (10.0 ± 3.2 to 6.7 ± 3.6, p < 0.001) with no significant difference between groups. Both groups also had significant improvement in anatomical and disability scores. There was no postoperative mortality in either group. The OSPS group had significantly more wound complications (45%) than the SEPS group (7%) (p < 0.005). The hospital stay and readmission rate for wound problems were also higher in the OSPS group. Conclusions: The early outcome showed equal improvement in clinical venous dysfunction scores in the 2 groups, but with significantly fewer complications in the SEPS group. Although the long-term durability of the endoscopic approach has not been determined, the short-term results would favor SEPS for treatment of severe venous insufficiency when perforator incompetence is a significant component.

Risk Factors for Venous Thromboembolism Following Prolonged Air Travel: A “Prospective” Study

The aim of this study was to analyze patients with air-travel-related venous leg thromboembolism (VTE) concerning the occurrence of patient-related and cabin-related risk factors. Twenty-five patients, still in hospital, with deep-vein thrombosis (DVT) and/or pulmonary embolism (PE) with onset of symptoms during or after air travel were questioned according to a study protocol. There were 14 women and 11 men with an age range of 36-79 years. Flight times were 5-18 hours. All patients had DVT, and nine (36%) had PE as well. The proximal extensions of the thrombus were in tibial vein, five patients; popliteal vein, two patients; superficial femoral vein, three patients; common femoral vein, four patients; greater saphenous vein, four patients; and iliac vein, seven patients. All but two patients (92%) had one or more patient-related risk factors; the mean was three. Overweight was present in 76% of the patients; chronic heart disease in 44%; hormone medication in 40%; chronic disease, except chronic heart disease and malignancy in 32%; history of previous VTE in 28%; malignancy in 28%; smoking in 20%; recent lower limb injury in 16%; and recent surgery in 12%. Only two patients had no known patient-related risk factor. The flight travel itself does not seem to be an important risk factor in healthy individuals. However, when patient-related risk factors are superimposed, there is increasing evidence that cabin-related risk factors, such as immobilization, cramped “coach” position, insufficient fluid intake, low humidity, and hypoxia contribute to development of VTE. Improved information is required so that passengers can prepare their travel in good time. Active precautions are recommended.

A comparison of surgery for neurogenic thoracic outlet syndrome between laborers and nonlaborers

OBJECTIVE To determine factors of outcome following surgical intervention for neurologic thoracic outlet syndrome (NTOS). METHODS In a retrospective study of patients surgically treated for NTOS, outcome was evaluated by postoperative symptoms and the ability of patients to return to work. RESULTS Good, fair, and poor results were obtained in 26 (48%), 21 (39%), and 7 (13%) patients, respectively. The best predictor of a good outcome was occupation. Nonlaborers were more likely to have good outcome (21 of 32, 66%) when compared with laborers (5 of 22, 23%; P = 0.0025). Only 6 of 20 (30%) laborers were able to return to their original occupation compared with 17 of 26 (65%) nonlaborers (P = 0.036). CONCLUSIONS Laborers with NTOS are less likely to have a good result from surgical intervention, are unlikely to return to their original occupation, and may require retraining for a non-labor-intensive occupation if they cannot return to their original work.