When the chimney is blocked: malignant renovascular hypertension after endovascular repair of abdominal aortic aneurysm.

BACKGROUND: The Chimney graft (CG) procedure is one of the novel modification techniques of the endovascular aneurysm repair (EVAR) surgery to treat suprarenal and juxtarenal abdominal aortic aneurysms. Other indications for the use of CG placement include thoracic and thoracoabdominal aneurysms with supraortic branches orifice involvement and cases of common iliac artery aneurysms with or without internal iliac artery involvement. The technique is used in patients who due to aortic-neck morphology and lack of adequate fixation and/or sealing zones are not eligible for standard EVAR. In this procedure, a parallel stent-graft is placed adjacent to the main body of the aortic endograft to maintain blood supply to renovisceral or supraortic branches, once the body of the aortic stent-graft is deployed. Symptomatic occlusions of the CG with novel renovascular hypertension were not described until now. CASE PRESENTATION: A-64-year-old male patient, presented with new-onset malignant hypertension, 13 months after an EVAR operation with CG placement to the left renal artery. The patient was on preventive clopidrogel therapy, which was withheld temporarily for several days, one month before presentation. Imaging studies revealed a novel form of iatrogenic renovascular hypertension, caused by occlusion of the CG. Any attempt to recanalize the covered stent or revascularize the left kidney was rejected and conservative treatment was chosen. Seven months after presentation, blood pressure was within normal ranges with little need for antihypertensive therapy. CONCLUSIONS: Physicians should be aware that the novel emerging techniques of EVAR to overcome the limitations of the aortic-neck anatomy may still adversely influence the renal outcome with potential development of new-onset hypertension.

Preferential use of basilic vein for surgical repair of popliteal aneurysms via the posterior approach.

The facedown position used for the posterior surgical approach to repair popliteal aneurysms limits access to the great saphenous vein. Using the basilic vein as the conduit of choice in five patients, we were able to harvest the vein conveniently and simultaneously with aneurysm exposure. On follow-up of 4 to 36 months, all grafts were functioning well.

Preoperative thallium scanning, selective coronary revascularization, and long-term survival after major vascular surgery.

BACKGROUND: Ischemia on thallium scanning is a strong predictor of long-term mortality in CAD patients. Whether coronary revascularization (CR) in patients with significant ischemia on preoperative thallium scanning (PTS) improves long-term survival after major vascular surgery has not been determined. METHODS AND RESULTS: The perioperative data, including PTS and subsequent CR in patients with moderate to severe reversible ischemia on PTS, and long-term survival of 502 consecutive patients who underwent 578 major vascular procedures were analyzed retrospectively. Patients with PTS who ultimately did not undergo the planned vascular operation were also studied. Cox regression and propensity score analyses were used to analyze survival. A total of 407 patients (81.1%) had PTS: 221 (54.3%) had no or mild defects (group I); 50 (12.3%) had moderate-severe fixed defects (group II); 62 (15.2%) had moderate-severe reversible ischemia yet did not undergo CR (group III); and 74 (18.2%) had moderate-severe reversible ischemia and subsequent CR by CABG (36) or PTCA (38; group IV). Patients who sustained major complications as a result of the preoperative cardiac workup were included in group IV. By multivariate analysis, age, type of vascular surgery, presence of diabetes, previous myocardial infarction, and moderate-severe ischemia on PTS independently predicted mortality (P=0.001, 0.009, 0.039, 0.006, and 0.029, respectively), and preoperative CR predicted improved survival (OR 0.52, P=0.018). Group IV had better survival than group III even when subdivided according to normal and reduced left ventricular function (OR 0.40 and 0.41, P=0.035 and 0.021, respectively). CONCLUSIONS: Long-term survival after major vascular surgery is significantly improved if patients with moderate-severe ischemia on PTS undergo selective CR.

Association of cardiac troponin, CK-MB, and postoperative myocardial ischemia with long-term survival after major vascular surgery.

OBJECTIVES: The aim of this study was to determine the long-term prognosis with postoperative markers of myocardial ischemia and infarction. BACKGROUND: Cardiac troponins (cTn) are superior to creatine kinase-MB fraction (CK-MB) in detecting perioperative myocardial infarction (PMI). However, their threshold levels signifying PMI and their long-term prognostic value are not yet determined. METHODS: A cohort of 447 consecutive patients who underwent 501 major vascular procedures was prospectively studied. Perioperative continuous 12-lead electrocardiogram monitoring, cardiac troponin-I (cTn-I) and/or cardiac troponin-T (cTn-T), and CK-MB levels on the first three postoperative days, and long-term survival were determined. The association of different cutoff levels of CK-MB, troponin, and ischemia duration with long-term survival was investigated. RESULTS: Between 14 (2.9%) and 107 (23.9%) of the patients sustained PMI, depending on the biochemical criteria used. Elevated postoperative CK-MB, cTn, and prolonged (>30 min) ischemia, at all cutoff levels examined, predicted long-term mortality independent of the preoperative predictors: patient's age, type of vascular surgery, previous myocardial infarction, and renal failure (Cox multivariate analysis). Both CK-MB >10% and cTn-I >1.5 ng/ml and/or cTn-T >0.1 ng/ml independently predicted a 3.75-fold and 2.06-fold increase in long-term mortality (p = 0.006 and 0.012, respectively). Similarly, both CK-MB >5% and cTn-I >0.6 ng/ml and/or cTn-T >0.03 ng/ml independently predicted a 2.15-fold and 1.89-fold increase in mortality (p = 0.018 and 0.01, respectively). Patients with both these markers elevated had a 4.19-fold increase in mortality (p < 0.001). CONCLUSIONS: Postoperative CK-MB and troponin, even at low cutoff levels, are independent and complementary predictors of long-term mortality after major vascular surgery.

Vascular trauma in high-velocity gunshot wounds and shrapnel-blast injuries in Israel.

High-velocity gunshot and shrapnel-blast vascular injuries pose a great challenge and need to be approached in a systematic, multidisciplinary fashion. Early revascularization with temporary shunts, the use of autologous tissue, major venous reconstruction, a low threshold for fasciotomy, and reliable tissue coverage are the mainstays of management.

Size of normal and aneurysmal popliteal arteries: a duplex ultrasound study.

OBJECTIVE: To define diameter at three levels along the popliteal artery and its relation to the inflow arteries in the normal state and in popliteal aneurysms. METHODS: The external diameter of the arteries was determined by duplex ultrasound scanning at the common femoral (CFA), superficial femoral artery (SFA), proximal popliteal artery (PPOP), mid-popliteal artery (MPOP), and distal popliteal artery (DPOP). Examinations were performed in 104 healthy men and 100 women. In addition, patients were screened for the presence of popliteal aneurysms (diameter >10 mm). Findings in healthy male subjects were compared with those with popliteal aneurysms. RESULTS: Mean arterial diameters in normal men were larger than in women, but the SFA/CFA ratio was smaller in women (0.74 +/- 0.08 vs 0.78 +/- 0.09; P < .001) and the MPOP/SFA ratio was larger (0.98 +/- 0.11 vs 0.94 +/- 0.12; P = .001). In both genders, normal popliteal artery diameter was not uniform throughout its length, with PPOP and MPOP being nearly identical, and DPOP was smaller. MPOP diameter correlated most closely with SFA diameter (r = 0.51; P < .001) and less with height, weight and body surface area (r = 0.2 to 0.3) and was not associated with age or the presence of hypertension. In 27 men with 45 patent, fusiform popliteal aneurysms (10 to 44 mm) the site of maximal dilatation was in the region of the MPOP in 39 cases and near the PPOP in only 6 cases. The DPOP was never the largest segment and only in one case was it >10 mm. Arterial diameter in aneurysm patients was larger than normal at all levels but was greatest near the MPOP level (15.7 +/- 6.9). Popliteal-to-SFA diameter ratios were increased in the aneurysm group at all three levels but were greatest at the MPOP level (1.85 vs 0.94, P < .001). Comparing 15 popliteal aneurysms >20 mm with smaller ones, distal popliteal artery changed to the least extent but did increase in diameter (6.1 +/- 1.2 vs 7.0 +/- 1.4, P < .04). In larger aneurysms the MPOP/SFA ratio increased from 1.54 to 2.5 (P < .001). CONCLUSION: The diameter of the normal popliteal artery is not uniform throughout its length. In popliteal aneurysms, the region of the MPOP is most commonly the largest diameter. The MPOP/SFA ratio is greater than normal in popliteal aneurysms and increases in larger aneurysms. DPOP does dilate but to a lesser extent then PPOP and MPOP, making endovascular repair anatomically feasible in most popliteal aneurysms.

Survival with intact cerebral function after gunshot injury to both internal carotid arteries.

A 24-year-old man was admitted after sustaining a single gunshot wound to the neck with an expanding hematoma on the left. Computed tomography angiography demonstrated bilateral internal carotid artery pseudoaneurysms, with disruption of flow on the left and a carotid-jugular fistula on the right. At operation, transection of the left internal carotid artery necessitated ligation of the artery. No injuries to the trachea or larynx were found, but the pharynx was lacerated and was repaired. The patient was transferred to the angiography suite where a stent graft was placed in the right internal carotid artery. This served to close the pseudoaneurysm and the arteriovenous fistula while preserving distal flow. The patient recovered with intact cerebral function and with mild paresis of the tongue related to hypoglossal nerve injury. He was discharged home after 7 days.

The first 150 endovascular AAA repairs at a single institution: how steep is the learning curve?

PURPOSE: To determine whether increasing experience with endovascular abdominal aortic aneurysm (AAA) repair in a single institution will result in improved outcome. METHODS: A retrospective review was undertaken of 150 consecutive cases of endovascular AAA repairs performed using the AneuRx device between October 1996 and April 2000 in a university-based medical center. The population was divided into early and late groups of 75 patients each. Endpoints included technical success; complications; early (< or =30-day) morbidity, mortality and rupture; endoleak at discharge and at 1 month; early secondary intervention; proximal neck and iliac tortuosity; extender cuff placement; femoral reconstructions beyond primary repair; total fluoroscopy time; and contrast load. RESULTS: Baseline patient and aneurysm characteristics were similar between the 2 groups. Technical success was 98.7%; 2 cases were converted intraprocedurally owing to difficult iliac access (early group) and a severely angulated proximal neck (late group). There was a tendency toward more frequent use of intraoperative proximal extender cuffs in the early group (12% versus 4% in the late group, p=0.13). Femoral reconstructions were more frequent in the early group (36% versus 19%, p<0.025). While total contrast volume was similar (111 +/- 56 versus 105 +/- 45 mL, p=NS), total fluoroscopy time was significantly reduced (p<0.05) between the early and late groups. CONCLUSION: With attention to detail and careful patient selection, successful endovascular AAA repair can be achieved with very few conversions and low perioperative mortality even during the center's early experience. Evidence indicates, however, that a learning curve definitely exists, as shown by fewer access site problems, more accurate device deployments, and decreased fluoroscopy times as proficiency is attained.

Changes in aneurysm volume after endovascular repair of abdominal aortic aneurysm.

OBJECTIVE: The purpose of this study was to define changes in aneurysm volume after endovascular repair of abdominal aortic aneurysm. METHODS: A total of 154 consecutive patients who underwent endovascular repair of abdominal aortic aneurysm with the Medtronic AneuRx stent graft at Stanford University Hospital were evaluated. During a mean follow-up period of 15.8 +/- 11.3 months, serial computerized measurements of aneurysm volume and orthogonal maximal diameter were performed on helical computed tomographic scan data sets and maximal transverse diameter was measured manually from transverse computed tomographic images. Aortoiliac length (renal to hypogastric artery origin) was measured along the median luminal centerline and along the straight line. RESULTS: Aneurysm volume increased immediately after endovascular repair (from 180.2 +/- 69.9 mL to 187.9 +/- 71.6 mL; P <.001), but orthogonal and transverse diameter and aortoiliac length did not change significantly. During the follow-up period, mean volume decreased to 171.9 +/- 70.2 mL (P <.05) and straight-line and centerline aortoiliac length remained unchanged from preoperative values. Overall, volume decreased at a rate of 1.7 +/- 5.9 mL/mo (P <.001). During periods without endoleak, the rate of decrease was 3.2 +/- 5.5 mL/mo (P <.001), and during periods with endoleak, aneurysm volume increased at a rate of 2.0 +/- 5.3 mL/mo (P <.005), without a difference between types of endoleak. Predictive values for the presence of endoleak were similar for transverse and orthogonal diameter and volume. Logistic regression analysis showed volume to be most closely associated with the presence of endoleak. CONCLUSION: Aneurysm volume increases immediately after endovascular repair. After repair, aneurysm volume gradually decreases and aortoiliac length remains unchanged. Changes in volume parallel changes in maximal aneurysm diameter, and their association with the presence of an endoleak does not appear to be appreciably stronger.

Late endoleak after endovascular repair of an abdominal aortic aneurysm with multiple proximal extender cuffs.

Late onset graft or attachment site-related endoleaks may be hazardous, and early identification of patients at risk is important. We describe a patient who underwent implantation of a bifurcated stent graft 5.5 cm below the renal arteries because of a technical error with three extender cuffs implanted proximally to bridge the gap. During the 1st year, aneurysm diameter decreased from 68 to 52 mm. After 1 year, the patient had an acute endoleak develop, which originated between two of the extender cuffs and which was accompanied by severe abdominal pain and reexpansion of the aneurysm. This endoleak was treated with insertion of an additional bifurcated stent graft within the extender cuff segment. The patient has been subsequently followed for 6 months and has had no endoleak or symptoms, and aortic diameter has decreased once again to 55 mm.

Gender differences in endovascular abdominal aortic aneurysm repair with the AneuRx stent graft.

OBJECTIVE: The objective of this study was to evaluate gender differences in the selection, procedure, and outcome of endovascular abdominal aortic aneurysm repair (EVAR). PATIENTS: Between October 1996 and January 2001, 378 patients were evaluated for EVAR and 189 patients underwent EVAR with the Medtronic AneuRx stent graft at a single center. RESULTS: Women constituted 17% of patients considered for EVAR. Their eligibility rate (49%) did not differ significantly from that of men (57%), and they constituted 14% of patients who underwent EVAR (26/189). Women who underwent EVAR were older (77.9 +/- 6.3 years versus 73.1 +/- 8.1 years; P <.005) with a higher rate of chronic obstructive lung disease (50% versus 28%; P <.05). Maximal aneurysm diameter (57.2 +/- 10.9 mm versus 57.8 +/- 9.4 mm; not significant) did not differ between men and women. Mean diameters of the proximal neck (20.4 +/- 2.3 mm versus 22.3 +/- 2.0 mm; P <.01), common iliac arteries (11.4 +/- 1.2 mm versus 13.5 +/- 3.6 mm; P <.001), and external iliac arteries (7.9 +/- 0.7 mm versus 9.4 +/- 1.4 mm; P <.001) were all smaller in women, and abdominal aortic aneurysm/neck diameter ratio was larger (2.82 +/- 0.59 versus 2.60 +/- 0.49; P <.05). The length of the proximal aortic neck was shorter in women (20.7 +/- 8.2 mm versus 24.5 +/- 11.8 mm; P <.05). Women had significantly more intraoperative complications (31% versus 13%; P <.05), primarily related to arterial access, and needed more frequent arterial reconstruction (42% versus 21%; P <.05), without a difference in postoperative mortality rate (0/26 versus 2/163; not significant) and complication rate (23% versus 20%: not significant). During a follow-up period of 13.8 +/- 11.7 months, no gender-related difference was found in survival rate, endoleak rate, or reintervention rate or in the rate of change in aneurysm diameter or volume. CONCLUSION: Eligibility rates of women for EVAR are similar to those of men. Women are at an increased risk for access-related complications during EVAR, but outcome is equivalent to that of men.

Open versus endovascular AAA repair in patients who are morphological candidates for endovascular treatment.

PURPOSE: To compare the outcomes of open versus endovascular repair of abdominal aortic aneurysm (AAA) in a cohort of patients who fulfill morphological criteria for endovascular repair. METHODS: A retrospective review of 229 consecutive AAA patients treated over a 3-year period identified 149 patients who were candidates for endovascular repair based on preoperative computed tomography and angiography. Of the 149 patients, 79 (68 men; mean age 74 +/- 8 years) underwent endovascular repair with the AneuRx stent-graft; the remaining 70 (56 men; mean age 72 +/- 8 years) had open repair. Short-term outcome measures were 30-day mortality and procedure-related morbidity, length of stay in the intensive care unit and hospital, intraoperative blood loss, interval to oral diet, and time to ambulation. Long-term outcome measures included death and secondary procedures. RESULTS: There was no difference in the 30-day mortality between endovascular repair (2, 2.5%) and open repair (2, 2.9%), even though endovascular patients had more comorbidities (p<0.05). Overall length of stay was reduced for endovascular patients (3.9 +/- 2.4 days versus 7.7 +/- 3.1 days for surgical patients, p<0.0001). Fewer endograft patients had complications (24% versus 40% for open repair, p<0.05), and the severity of these complications was less, as evidenced by the shorter hospital stays for endovascular patients with complications compared to conventionally treated patients with complications (6.7 +/- 2.4 days versus 22.5 +/- 35.2 days, p<0.05). There were no aneurysm ruptures or late surgical conversions in either group. CONCLUSIONS: Patients with AAA who were endograft candidates but who were treated with open repair experienced more morbidity and had more complications than patients treated with stent-grafts. Despite increased comorbidities in the endograft patients, there was no increase in mortality compared to open repair. Both treatments required secondary procedures and appeared to be equally effective in preventing aneurysm rupture up to 3 years.