Robert Y. Rhee

Mesenteric venous thrombosis: Still a lethal disease in the 1990s

PURPOSE This study was designed to evaluate progress in diagnosis, management, and clinical outcome of mesenteric venous thrombosis (MVT). METHODS We retrospectively reviewed the clinical course of 72 patients treated for mesenteric venous thrombosis between 1972 and 1993. RESULTS Fifty-three patients had acute and 19 had chronic mesenteric venous thrombosis. Fifty-seven patients had secondary mesenteric venous thrombosis; previous abdominal surgical procedure and hypercoagulable states were the most prevalent associated conditions. Computed tomography was abnormal in all patients who underwent this test for acute mesenteric venous thrombosis and in 93% of those who had chronic disease. Angiography diagnosed acute mesenteric venous thrombosis in five (72%) of seven patients. Acute mesenteric venous thrombosis presented most frequently as abdominal pain (83%), anorexia (53%), and diarrhea (43%). Thirty-three (75%) had symptoms longer than 48 hours. Thirty-four (64%) patients with acute mesenteric venous thrombosis underwent a surgical procedure. Bowel resection was necessary in 31 patients. One patient had unsuccessful mesenteric venous thrombectomy. Seven patients with acute mesenteric venous thrombosis underwent anticoagulation without a surgical procedure, and 12 were observed. All patients with chronic mesenteric venous thrombosis were observed; nine of the 19 underwent anticoagulation. The median delay in diagnosis for patients with acute mesenteric venous thrombosis was 48 hours and did not decrease during the last decade. Mesenteric venous thrombosis recurred in 19 (36%) patients. The 30-day mortality was 27%. Long-term survival of patients with acute mesenteric venous thrombosis was significantly worse than that of those with chronic disease (36% vs 83% survival at 3 years). The patients with acute mesenteric venous thrombosis who underwent anticoagulation with and without surgical procedure had improved survival when compared with the observed group. CONCLUSION Acute mesenteric venous thrombosis remains a lethal disease. Mortality has not improved in the last 22 years. Computed tomography is the most sensitive diagnostic test. Anticoagulation and surgical procedure enhanced survival in the acute subgroup. The underlying disease determined survival in chronic disease.

Does hostile neck anatomy preclude successful endovascular aortic aneurysm repair

OBJECTIVES Poor outcomes have been reported with endovascular aneurysm repair (EVAR) in patients with hostile neck anatomy. Unsupported endografts with active fixation may offer certain advantages in this situation. We compared EVAR results using the Ancure (Guidant) endograft in patients with and without hostile neck anatomy. METHODS Records of EVAR patients from October 1999 to July 2002 at a tertiary care hospital were retrospectively reviewed from a division database. Patients with elective open abdominal aortic aneurysm (AAA) repair during the same period were reviewed to determine those unsuitable for EVAR. Hostile neck anatomy, assessed by computer tomography (CT) scans and angiograms, was defined as one or more of the following: (1) neck length </=10 mm, (2) focal bulge in the neck >3 mm, (3) >2-mm reverse taper within 1 cm below the renal arteries, (4) neck thrombus > or =50% of circumference, and (5) angulation > or =60 degrees within 3 cm below renals. RESULTS Three hundred and twenty-two patients underwent EVAR with an average follow-up of 18 months. Patients in Phase II trials (n = 41), repaired with other graft types (n = 48), or without complete anatomic records (n = 27) were excluded. Demographics and co-morbidities were similar in the 115 good-neck (GN) and 91 bad-neck (BN) patients except for age (mean, 72.9 years GN vs 75.7 BN; P = 0.13), gender (11% female GN vs 22% BN; P =.04); neck length (mean, 21.8 mm GN vs 14.4 mm BN: P <.001), and angulation (mean, 22 degrees GN vs 40 degrees BN; (P <.001). Perioperative mortality (0 GN vs 1.1% BN), late mortality (5.2% GN vs 4.4% BN), all endoleaks (19.1% GN vs 17.6% BN), proximal endoleaks (0.8% GN vs 2.1% BN), and graft migration (0 for both groups) did not reach statistical significance. Neck anatomy precluded EVAR in 106 of 165 (64%) patients with open AAA. CONCLUSIONS Unsupported endografts with active fixation can yield excellent results in treating many medically compromised patients with hostile neck anatomy. Nonetheless, an unsuitable neck remains the most frequent cause for open abdominal AAA.

Thrombin injection versus compression of femoral artery pseudoaneurysms

OBJECTIVE The compression of femoral artery pseudoaneurysms is a time consuming, painful, and sometimes unsuccessful procedure. Thrombin injection has been advocated as a superior alternative. In this study, we compare our experiences with both techniques. METHODS All the records of femoral artery false aneurysms that were treated in the vascular laboratory from January 1996 to April 1999 were retrospectively reviewed. Treatment with ultrasound scan-guided compression was compared with treatment with dilute thrombin injection (100 U/mL). RESULTS Both groups had similar demographics and aneurysm sizes (P >.2). Of the pseudoaneursyms, 88% were caused by cardiac catheterization and the others were the results of femoral artery access for cardiac surgery (6%), arteriography (5%), and renal dialysis (1%). Compression was successful in 25 of 40 patients (63%). Nine persistent aneurysms necessitated operation, and six were treated successfully with thrombin injection. Primary thrombin injection successfully obliterated 21 pseudoaneurysms in 23 patients. Overall, 27 of 29 pseudoaneurysms were treated successfully with thrombin injection (93%). Thrombosis occurred within seconds of the thrombin injection and required, on average, 300 units of thrombin (100 to 600 units). The patients who underwent successful compression required an average of 37 minutes of compression (range, 5 to 70 minutes) and required analgesia on several occasions. No patients in the thrombin group required analgesia or sedation. Neither group had complications. A cost analysis shows that thrombin treatment results in considerable savings in vascular laboratory resource use but not in overall hospital expenditures. CONCLUSION Ultrasound scan-guided thrombin injection is a safe, fast, and painless procedure that completely obliterates femoral artery pseudoaneurysms. The shift from compressive therapy to thrombin injection reduces vascular laboratory use and is less expensive, although it does not significantly impact hospital costs.

Duplex ultrasound as the sole long-term surveillance method post-endovascular aneurysm repair: A safe alternative for stable aneurysms

OBJECTIVE Long-term surveillance with computed tomography (CT) after endovascular aneurysm repair (EVAR) increases both cost and risk. The purpose of this study was to evaluate the safety of an alternative follow-up modality with color flow duplex ultrasound scanning (CDU) as the sole method of imaging. METHODS In 2003, we initiated a new follow-up (FU) schedule with yearly CDU as the sole imaging method for selected patients. Indications included a residual sac of less than 4 cm, expanded later to stable sac size for more than 2 years. A stable type II endoleak was not a contraindication. CT scans were obtained selectively-based on suspicious findings of a new endoleak or enlarging sac on CDU. The records of all patients with at least 1 year FU under this schedule were reviewed. RESULTS One hundred eighty-four patients were followed with CDU only for 1 to 4 years for a mean of 24 +/- 13 months. The new schedule was initiated at a mean of 34 +/- 24 months after EVAR (range 1-112 months). Twenty-three patients had previous endoleaks that had resolved spontaneously or had been treated. During CDU FU, three new endoleaks were detected, one with sac enlargement. All prompted CT evaluation: one type II endoleak with stable sac size could not be identified on CT 3 months later, and two distal type I endoleaks that required limb extension. All three had a prior Ancure endograft. No ruptures or graft occlusions were noted. One abdominal aortic aneurysm (AAA) related death followed graft explantation for infection. There were two additional deaths from malignancy and two from cardiac causes. After the FU switch, freedom from endoleaks was 96%, and from secondary interventions 95% at 48 months by life table method. Mean AAA diameter at baseline was 54 +/- 8 mm and decreased to 40 +/- 11 mm before the switch to CDU only FU. At last FU mean aneurysm diameter was 39 +/- 11 mm. When the current switch criteria were applied to a consecutive series of 200 EVAR patients, 97% would have been eligible for CDU only surveillance by 3 years postoperatively. CONCLUSIONS CDU only surveillance post-EVAR is safe and can be initiated early after treatment in patients with shrinking or stable aneurysms. This policy should result in cost savings advantage and avoid the complications associated with CT.

Management of splenic artery aneurysms: the significance of portal and essential hypertension.

BACKGROUND Splenic artery aneurysm(s) (SAA) are rare. But the incidence and significance of SAA among patients with portal hypertension (PHTN), especially among those who undergo orthotopic liver transplantation (OLT), have not been clearly delineated. STUDY DESIGN An 11-year (February 1987 to June 1998) retrospective review of our experience with treated SAA was performed. Patient characteristics, risk factors, clinical presentation, surgical management, aneurysm characteristics, and patient outcomes were assessed. Patients were separated according to a history of PHTN for analysis. Patients were also subdivided into ruptured versus elective presentations. RESULTS Thirty-four patients (22 in the PHTN group) were treated for SAA during the study period. Sixty-two percent (21 of 34) were women; the average age was 50.6 years. In patients without a history of PHTN (n = 12), essential hypertension was a significant risk factor (p < 0.001) for development of SAA. All patients underwent surgical treatment for SAA: resection with splenectomy (n = 23), ligation with splenectomy (n = 5), ligation of SAA only (n = 4), and vascular reconstruction (n = 2). The average size of all treated SAA was 4.8 +/- 2.6 cm, ranging from 1.5 to 12cm. Operative mortality after SAA rupture (n = 15) was 40%, compared with zero mortality for elective SAA repair (n = 19, p < 0.005). Rupture of SAA was associated with a higher mortality in patients with PHTN compared with patients without such history (56% versus 17%, respectively). After a mean followup period of 46 months, survival after rupture was 60% in contrast to 84% after elective repair. The majority of our patients with a history of PHTN (20 of 22) has undergone OLT, representing 0.46% of all OLT recipients (n = 4,374) during the study period. In four patients, SAA were repaired concurrently during transplantation. Of the 7 patients presented with rupture of SAA after OLT, 6 patients presented within 3 to 16 days postoperatively, with a median of 6 days and an overall mortality of 57%. CONCLUSIONS Essential hypertension and PHTN appear to be significant risk factors for development of SAA. Rupture of SAA is associated with a significant mortality, highest among patients with PHTN. Elective repair remains a safe and effective method of treatment. The significance of SAA is recognized among patients undergoing liver transplantation. A decision should be made to screen and electively treat SAA found in liver transplant patients, especially if the aneurysm is larger than 1.5 cm. Awareness of the increased rupture risk is crucial in management during the immediate posttransplant period.

Progression of asymptomatic carotid stenosis: A natural history study in 1004 patients ☆ ☆☆

PURPOSE The purpose of this study was to delineate the natural history of the progression of asymptomatic carotid stenosis. METHODS In a 10-year period, 1701 carotid arteries in 1004 patients who were asymptomatic were studied with serial duplex scans (mean follow-up period, 28 months; mean number of scans, 2.9/patient). At each visit, stenoses of the internal carotid artery (ICA) and the external carotid artery (ECA) were categorized as none (0 to 14%), mild (15% to 49%), moderate (50% to 79%), severe (80% to 99%), preocclusive, or occluded. Progression was defined as an increase in ICA stenosis to >/=50% for carotid arteries with a baseline of <50% or as an increase to a higher category of stenosis if the baseline stenosis was >/=50%. The Cox proportional hazards model was used for data analysis. RESULTS The risk of progression of ICA stenosis increased steadily with time (annualized risk of progression, 9.3%). With multivariate modeling, the four most important variables that affected the progression (P <.02) were baseline ipsilateral ICA stenosis >/=50% (relative risk [RR], 3.34), baseline ipsilateral ECA stenosis >/=50% (RR, 1.51), baseline contralateral ICA stenosis >/=50% (RR, 1.41), and systolic pressure more than 160 mm Hg (RR, 1. 37). Ipsilateral neurologic ischemic events (stroke/transient ischemic attack) occurred in association with 14.0% of the carotid arteries that were studied. The progression of ICA stenosis correlated with these events (P <.001), but baseline ICA stenosis was not a significant predictor. CONCLUSION In contrast to recently published studies, we found that the risk of progression of carotid stenosis is substantial and increases steadily with time. Baseline ICA stenosis was the most important predictor of the progression, but baseline ECA stenosis also was identified as an important independent predictor. Contralateral ICA stenosis and systolic hypertension were additional significant predictors. We found further that the progression of ICA stenosis correlated with ischemic neurologic events but not baseline stenosis. The data provide justification for the use of serial duplex scans to follow carotid stenosis and suggest that different follow-up intervals may be appropriate for different patient subgroups.

Predictors of failure and success of tibial interventions for critical limb ischemia

OBJECTIVE The efficacy of tibial artery endovascular intervention (TAEI) for critical limb ischemia (CLI) and particularly for wound healing is not fully defined. The purpose of this study is to determine predictors of failure and success for TAEI in the setting of CLI. METHODS All TAEI for tissue loss or rest pain (Rutherford classes 4, 5, and 6) from 2004 to 2008 were retrospectively reviewed. Clinical outcomes and patency rates were analyzed by multivariable Cox proportional hazards regression and life table analysis. RESULTS One hundred twenty-three limbs in 111 patients (62% male, mean age 74) were treated. Sixty-seven percent of patients were diabetics, 55% had renal insufficiency, and 21% required hemodialysis. One hundred two limbs (83%) exhibited tissue loss; all others had ischemic rest pain. All patients underwent tibial angioplasty (PTA). Tibial excimer laser atherectomy was performed in 14% of the patients. Interventions were performed on multiple tibial vessels in 20% of limbs. Isolated tibial procedures were performed on 50 limbs (41%), while 73 patients had concurrent ipsilateral superficial femoral artery or popliteal interventions. The mean distal popliteal and tibial runoff score improved from 11.8 ± 3.6 to 6.7 ± 1.6 (P < .001), and the mean ankle-brachial index increased from 0.61 ± 0.26 to 0.85 ± 0.22 (P < .001). Surgical bypass was required in seven patients (6%). The mean follow up was 6.8 ± 6.6 months, while the 1-year primary, primary-assisted, and secondary patency rates were 33%, 50%, and 56% respectively. Limb salvage rate at 1 year was 75%. Factors found to be associated with impaired limb salvage included renal insufficiency (hazard ratio [HR] = 5.7; P = .03) and the need for pedal intervention (HR = 13.75; P = .04). TAEI in an isolated peroneal artery (odds ratio = 7.80; P = .01) was associated with impaired wound healing, whereas multilevel intervention (HR = 2.1; P = .009) and tibial laser atherectomy (HR = 3.1; P = .01) were predictors of wound healing. In patients with tissue loss, 41% achieved complete closure (mean time to healing, 10.7 ± 7.4 months), and 39% exhibited partial wound healing (mean follow up, 4.4 ± 4.8 months) at last follow up. Diabetes, smoking, statin therapy, and revascularization of > 1 tibial vessel had no impact on limb salvage or wound healing. Re-intervention rate was 50% at 1 year. CONCLUSIONS TAEI is an effective treatment for CLI with acceptable limb salvage and wound healing rates, but requires a high rate of reintervention. Patients with renal failure, pedal disease, or isolated peroneal runoff have poor outcomes with TAEI and should be considered for surgical bypass.

Pharmacomechanical thrombectomy for iliofemoral deep vein thrombosis: An alternative in patients with contraindications to thrombolysis

OBJECTIVE Venous lysis is usually reserved for symptomatic patients with acute deep vein thrombosis (DVT) and low risk for bleeding. This study reports the use of pharmacomechanical thrombectomy (PMT) in patients with contraindications to thrombolysis. METHODS A retrospective review of all patients with symptomatic DVT treated between 2007 and 2008 with PMT was performed. All patients were treated by a combination of local tissue plasminogen activator (tPA) with the Angiojet (Possis Medical, Minneapolis, Minn) or Trellis device (Bacchus Vascular, Santa Clara, Calif). Catheter-directed lysis was used sparingly. RESULTS Forty-three patients (mean age, 48.4 +/- 16.6 years) presented with symptoms averaging 13.6 +/- 9.6 days in duration. Nineteen (44%) had symptoms for >14 days, and 15 (35%) had a high risk for bleeding. Symptomatic subclavian thrombosis occurred in eight (19%), and 35 (81%) presented with disabling lower extremity DVT (4 phlegmasia) despite anticoagulation. Fifteen patients had a thrombosed indwelling permanent filter. Sixty-three percent were treated in one session, but 16 patients required a lytic infusion after suboptimal PMT. Iliac stenting was required in 35% of limbs treated. Successful lysis (>50%) was achieved in 95% of patients and symptom resolution in 93%. All patients became ambulatory with no or minimal limitation. There were no major systemic bleeding complications, but access site hematoma occurred in two patients and worsening of pre-existing rectus sheath hematoma requiring transfusion occurred in another two. Limb salvage was maintained in 100% of patients who presented with phlegmasia. Mean follow-up was 5.0 +/- 4.8 months. Freedom from DVT recurrence and reintervention was 95% at 9 months by life-table analysis. CONCLUSIONS PMT can be safely and effectively used for subacute iliocaval and iliofemoral DVT and in patients with contraindications for lytic therapy, resulting in improved functional outcomes relative to their debilitated state before the procedure.

Endovascular interventions for TASC II D femoropopliteal lesions

BACKGROUND Advances in endovascular techniques have provided new options in the treatment of complex infrainguinal occlusive lesions. The purpose of this study was to evaluate outcomes of endovascular interventions on TransAtlantic InterSociety (TASC) II D femoropopliteal occlusive disease. METHODS All patients undergoing endovascular interventions for femoropopliteal occlusive disease between July 2004 and July 2009 were reviewed. Patient demographics, pre- and postprocedure ankle-brachial indices (ABI) and anatomic factors were analyzed. Outcomes evaluated included primary patency, assisted-patency, secondary patency, predictors of restenosis, and wound healing. RESULTS Five hundred eighty-five limbs were treated during the period reviewed. The study group included 79 TASC D limbs in 74 patients (mean age 76.5 +/- 11.9 years, male sex: 53%). Fifty-six limbs (71%) underwent treatment for critical limb ischemia, including 42 (53%) with tissue loss. Eleven patients (15%) had previous failed bypasses. Preoperative ABIs were unobtainable for 23 patients, while the remaining 56 had a mean baseline ABI of 0.54 +/- 0.28. There was one periprocedural mortality. Five patients (6.3%) had periprocedural complications. Mean increase in ABI postprocedure was 0.49 +/- 0.35. Follow-up was available for 74 limbs at a mean of 10.7 months (range, 1-35). There were 18 mortalities (24.3%) during the follow-up period. No patient required a major amputation during this follow-up period. Twenty-one limbs (26.6%) experienced restenosis and nine limbs (11.4%) experienced occlusion. Twenty-nine limbs underwent reintervention during the follow-up time, including nine which underwent multiple reinterventions. Primary, assisted-primary, and secondary patency rates at 12 and 24 months were 52.2%, 88.4%, 92.6% and 27.5%, 74.2%, and 88.9%, respectively. Predictors of restenosis/occlusion included hypercholesterolemia, the presence of a popliteal artery stent, and patients who were current or former smokers. CONCLUSIONS Endovascular interventions for TASC II D lesions can be safely performed with excellent hemodynamic improvement and limb salvage rates. Restenosis is not uncommon in this population, which mandates strict follow-up. Further follow-up is necessary to determine the long-term efficacy of these interventions.

Duplex criteria for determination of in-stent stenosis after angioplasty and stenting of the superficial femoral artery

OBJECTIVE Endovascular intervention is considered first-line therapy for most superficial femoral artery (SFA) occlusive disease. Duplex ultrasound (DU) criteria for SFA in-stent stenosis and correlation with angiographic data remain poorly defined. This study evaluated SFA-specific DU criteria for the assessment of SFA in-stent stenosis. METHODS From May 2003 to May 2008, 330 limbs underwent SFA angioplasty and stenting and were monitored by serial DU imaging. Suspected stenotic lesions underwent angiography and intervention when appropriate. Data pairs of DU and angiographically estimated stenosis <or=30 days of each other were analyzed. Seventy-eight limbs met these criteria, and 59 underwent reintervention. In-stent peak systolic velocity (PSV), the ratio of the stented SFA velocity/proximal SFA velocity, changes in ankle-brachial indices (ABIs), and the percentage of angiographic stenosis were examined. Linear regression and receiver operator characteristic (ROC) curve analyses were used to compare angiographic stenosis with PSV and velocity ratios (Vrs) to establish optimal criteria for determining significant in-stent stenosis. RESULTS Mean follow-up was 16.9 +/- 8.3 months. Of the 59 limbs that underwent reintervention, 37 (63%) were symptomatic, and 22 (37%) underwent reintervention based on DU findings alone. Linear regression models of PSV and Vr vs degree of angiographic stenosis showed strong adjusted correlation coefficients (R(2) = 0.60, P < .001 and R(2) = 0.55, P < 0.001, respectively). ROC curve analysis showed that to detect a >or=50% in-stent stenosis, a PSV >or=190 had 88% sensitivity, 95% specificity, a 98% positive predictive value (PPV), and a 72% negative predictive value (NPV); for Vr, a ratio of >1.50 had 93% sensitivity, 89% specificity, a 96% PPV, and a 81% NPV. To detect >or=80% in-stent stenosis, a PSV >or=275 had 97% sensitivity, 68% specificity, a 67% PPV, and a 97% NPV; a Vr ratio >or=3.50 had 74% sensitivity, 94% specificity, a 77% PPV, and a 88% NPV. Combining a PSV >or=275 and a Vr >or=3.50 to determine >or=80% in-stent stenosis had 74% sensitivity, 94% specificity, a 88% PPV, and a 85% NPV; odds ratio was 42.17 (95% confidence interval, 10.20-174.36, P < .001) to predict >or=80% in-stent stenosis. A significant drop in ABI (>0.15) correlated with a >62% in-stent stenosis, although the adjusted correlation coefficients was low (R(2) = 0.31, P = .02). CONCLUSION PSV and Vr appear to have a significant role in predicting in-stent stenosis. To determine >or=80% stenosis, combining PSV >or=275 cm/s and Vr >or=3.50 is highly specific and predictive.