A more proximal landing zone is preferred for thoracic endovascular repair of acute type B aortic dissections.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) has become first-line therapy for complicated acute type B aortic dissection (aTBAD). However, the strategy for optimal proximal landing zone remains to be determined. We compared early outcomes and late aortic-related adverse events in patients undergoing TEVAR for complicated aTBAD with endograft deployment in proximal landing zone 2 vs 3. METHODS: We performed a retrospective chart review of adult patients undergoing TEVAR for complicated aTBAD within 6 weeks of diagnosis from January 2008 to December 2018. We excluded patients with connective tissue disorders and prior type A repair. Patients were divided into landing zone 2 TEVAR (Z2T) and zone 3 TEVAR (Z3T) groups. Z2 patients were divided between left subclavian artery (LSA) revascularization (Z2R) vs LSA coverage without revascularization (Z2C). Groups were compared for the need for aortic reintervention within 36 months of initial admission and freedom from aortic-related adverse events and mortality (AREM), defined as the need for aortic reintervention, aortic-related death, or rupture. RESULTS: Eighty-three patients underwent TEVAR for complicated aTBAD within a mean of 4.1 ± 7.8 days; 89.5% of patients had less than 2 cm of healthy proximal descending thoracic aorta. The landing zone was Z3T in 35 patients and 48 underwent Z2T: 10 Z2C and 38 Z2R. There were no differences between Z2T and Z3T in time from diagnosis to TEVAR, demographics, comorbidities, and diameter aortic measurements. The 30-day survival was 87.8%-89.5% for Z2R, 88.6% for Z3, and 80.0% for Z2C (P = .610). The postoperative spinal cord ischemia rate was 3.7%-2.7% for Z2R, 0% for Z3T, and 20.0% for Z2C (P = .012). The postoperative thoracic aortic rupture was 2.2% in Z2 and 0 in Z3. The need for aortic reintervention at 36 months after TEVAR was lower for Z2T (10.4%) vs Z3T (31.4%; P = .025). Freedom from AREM at 36 months was higher in Z2T vs Z3T (87.5% vs 68.6%; P = .048). The freedom from proximal reintervention was higher in Z2T (95.8%) compared with Z3T (80.0%; P = .019). Z3T deployment was predictive for AREM (odd ratio, 3.648; 95% confidence interval, 1.161-11.465; P = .027) and need for proximal reintervention (odds ratio, 5.542; 95% confidence interval, 1.062-28.927; P = .042). CONCLUSIONS: Most patients with aTBAD have less than 2 cm of proximal healthy descending thoracic aorta. In patients treated for complicated aTBAD, Z2T is associated with a lower need for aortic reintervention and aortic-related adverse events than Z3T. Patients may benefit from a more aggressive proximal landing zone with similar perioperative morbidity when Z2T is done with LSA revascularization.

Impact of thoracic endovascular aortic repair timing on aortic remodeling in acute type B aortic intramural hematoma.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) is increasingly utilized in the management of acute type B aortic intramural hematoma (TBIMH). Optimal timing for intervention has not been described. The aim of this study was to evaluate TEVAR timing on postoperative aortic remodeling. METHODS: A retrospective chart review was performed on patients who underwent TEVAR for TBIMH from January 2008 to September 2018. Imaging was reviewed pre- and postoperatively. Primary data points included true lumen diameter (TLD) and total aortic diameter (TAD) at the site of maximal pathology. Primary endpoint was aortic remodeling evidenced by a TAD/TLD ratio closest to 1.0. Secondary outcome was occurrence of aortic-related adverse events and mortality (AREM): aortic rupture, aortic-related death, progression to dissection, or need for aortic reintervention within 12 months. Patients undergoing emergent TEVAR (within 24 hours, 'eTEVAR') were compared with the remainder - delayed TEVAR ('dTEVAR'). RESULTS: We analyzed 71 patients that underwent TEVAR for TBIMH; 25 underwent emergent TEVAR and 46 patients underwent dTEVAR (median, 5.5 days; range, 2-120 days). There were no differences in demographics and comorbidities, and patients did not differ in presenting IMH thickness (12.6 ± 3.1 vs 11.3 ± 4.1 mm; P = .186) nor presenting TAD/TLD ratio (1.535 ± 0.471 vs 1.525 ± 0.397; P = .928) for eTEVAR and dTEVAR groups, respectively. eTEVAR patients had larger average presenting maximal descending aortic diameter (45.8 ± 14.3 vs 38.2 ± 7.5 mm; P = .018) and higher incidence of penetrating aortic ulcer on presenting computed tomography angiography (52.0% vs 21.7%; P = .033). Thirty-day mortality was 2 of 25 (8.0%) for eTEVAR and 2 of 45 (4.4%) for dTEVAR (P = .602). Postoperative aortic remodeling was more complete in the dTEVAR group (1.23 ± 0.12 vs 1.33 ± 0.15; P = .004). Case-control matching (controlling for presenting descending aortic diameter and penetrating aortic ulcer) on 30 patients still showed better aortic remodeling in the dTEVAR group (1.125 ± 0.100 vs 1.348 ± 0.42; P < .001). The incidence of AREM was higher in the eTEVAR (6/25; 24.0%) group compared with the dTEVAR group (2/46; 4.3%). At 12 months, freedom from AREM was higher in the dTEVAR group (95.7% vs 76.0%; P = .011). Postoperative TAD/TLD ratio was the best predictor for late aortic-related adverse events (area under the receiver operator characteristic = 0.825; P = .003). CONCLUSIONS: TEVAR for acute TBIMH within 24 hours of admission is associated with lower aortic remodeling and higher occurrence of late AREM. Delaying TEVAR when clinically possible could improve aortic remodeling and aortic-related outcomes.

Dr Walter Henry Anderson (1870-1937) and the mission hospital at Safed, Palestine.

Walter Henry Anderson, a brewer's clerk in Burton-upon-Trent, became a missionary doctor, supported by a society promoting welfare and evangelism in Jewish communities abroad. His family background was rich in pastoral ministry at home and adventure abroad. Arguably, this background played a part in his decision to serve the Jews of Safed. His life in Palestine entailed much enterprise and hardship as he raised a family, fought disease and set up a mission hospital serving not only the Jewish community but persons of all faiths. His years in Palestine, from 1894 to 1915, were times of peace in the Middle East before the turmoil unleashed by the Great War. Jews from the Diaspora were gaining an increasing foothold in Palestine, their 'Promised Land'. Themes of that era - the rise of Zionism, confrontation between Judaism and evangelical Christianity, conflict between immigrant Jew and Palestinian Arab and the remarkable travels of Lawrence of Arabia were interwoven with the lives of Dr Anderson and his family.

Subintimal angioplasty of chronic total occlusion in iliac arteries: a safe and durable option.

BACKGROUND: Traditionally, aortobifemoral bypass has been the intervention of choice for iliac artery chronic total occlusions (CTOs). However, it is associated with significant morbidity and mortality, limiting its use in high-risk patients. To reduce procedural risk, subintimal angioplasty (SIA) for femoropopliteal CTO has been utilized by many, but few have extended this endovascular technique to treating iliac artery CTOs. We present our experience with 101 successful SIAs for iliac artery CTOs. METHODS: A retrospective review of consecutive patients with iliac artery CTOs treated with subintimal angioplasty from June 2000 to January 2009 was completed. Demographic and risk factor data were obtained, along with procedural data. Primary and secondary patency, survival, freedom from claudication, and limb salvage rates were determined by Kaplan-Meier survival analysis. Univariate and multivariate analyses were completed to identify factors adversely affecting primary patency. RESULTS: One hundred twenty patients underwent an attempted SIA of an iliac artery CTO, and 101 iliac artery CTOs were successfully treated, giving a technical success rate of 84%. Technical failure was due to the inability to re-enter the lumen in all cases. Indications for intervention were lifestyle-altering claudication in 64 patients (63%) and critical limb ischemia (CLI), in 37 (37%). Eighty-five patients underwent percutaneous SIA, while 11 patients underwent a combined SIA with surgical outflow procedure. Lesions were classified as TransAtlantic InterSociety Consensus (TASC) B, 39 (39%); TASC C, 27 (27%); and TASC D, 35 (35%). In 82 (81%) lesions, stents were deployed with an average of 1.2 (range, 0-3) stents utilized. A re-entry device was used in 14 (14%) lesions. Major complication rate was 3.0%, with a 30-day mortality rate of 1.0%. Primary and secondary patency rates at 1, 2, and 3 years were 86% and 94%, 76% and 92%, and 68% and 80%, respectively. Survival rate was 67% at 5 years, reflecting the poor health of this cohort. Limb salvage for CLI patients at 1 and 5 years was 97% and 95%, respectively. Freedom from claudication at 1 and 3 years was 89% and 73%. Univariate analysis identified hyperlipidemia, coronary artery disease, and prior surgical bypass in treated limb as factors for loss of primary patency; however, on multivariate analysis, no factors remained statistically significant. CONCLUSION: This study demonstrates that SIA of iliac CTOs is feasible and can be performed safely and effectively, even in high-risk patients. Excellent patency and limb salvage rates can be achieved. In our experience, the safety and durability of SIA makes it an attractive first-line therapy for iliac artery occlusive disease.

Outcomes of reinterventions after subintimal angioplasty.

OBJECTIVE: With increased use of subintimal angioplasty (SIA), the role of reintervention after recurrence is currently unknown. To more clearly define the technical feasibility, patency, and clinical outcomes of reinterventions after SIA, we reviewed our cumulative experience. METHODS: A retrospective review of patient information (including demographics, indications, procedures, noninvasive arterial studies, and postprocedural events) was performed on those patients undergoing reintervention after a primary subintimal angioplasty in the infrainguinal vessels. Continuous and noncontinuous data were compared using the Student t-test and the z test, respectively. Patency was calculated by Kaplan-Meier analysis. Survival curves were compared using log-rank and Wilcoxon testing for univariate analysis and Cox hazard-regression analysis for multivariate analysis. RESULTS: From December 2002, through July 2006, 495 SIAs were performed for infrainguinal disease in 482 patients. Of this cohort, 121 patients (25%) required 188 consecutive reinterventions. Each patient underwent an average of 1.5 +/- 0.8 (range, 1-7) reinterventions during this study. We analyzed only the outcomes of 124 consecutive, first reinterventions. Mean interval time between primary SIA and the first reintervention was 7.8 +/- 6.8 months (range, 1 day-31 months). Indications for reintervention were clinical only (recurrence of symptoms or worsening exam), diagnostics only (recurrence based on peripheral vascular lab studies), or both in 18%, 25%, and 52% of patients, respectively. Technical success was achieved in 94% (n = 117) of the procedures. Repeat SIA technique was utilized in 68% (n = 84) of reinterventions and other endovascular therapies (32%; n = 40), of which the majority were transluminal angioplasty, for the remaining reinterventions. Mean follow-up was 8.6 months (range, 0-34 months). The patency rate at 1 year for the first reintervention was 33%. One-year patency rates for reinterventions performed within 3 months of the primary SIA were worse than those performed after 3 months (22% vs 34%; P = .04). In addition, patients treated for claudication had better 1-year patency than those treated for critical limb ischemia (37% vs 27%; P = .03). Other demographic or procedural variables did not significantly affect patency. In patients with critical limb ischemia (CLI), limb salvage rate at 1 year was 71%. CONCLUSION: Endovascular reintervention after SIA is a safe and technically feasible procedure for recurrences and offers good limb salvage rate. Early reinterventions performed within 3 months of the original SIA portend a worse outcome. In addition, reinterventions are less durable in patients with CLI compared with claudication. Finally, by identifying a recurrent stenosis instead of an occlusion, close surveillance may contribute to improved overall outcome.

Retrograde open mesenteric stenting for acute mesenteric ischemia is a viable alternative for emergent revascularization.

OBJECTIVES: Significant comorbidities and an exhausted physiologic reserve lead to high mortality rates during operations for acute mesenteric ischemia. We present our experience with retrograde open mesenteric stenting. METHODS/RESULTS: A total of 3 female patients (mean age = 74.1 years) with acute mesenteric ischemia underwent exploratory laparotomy. Operative technique included isolating the superior mesenteric artery for cannulation and retrograde endovascular angioplasty and stenting. One required small bowel resection. All 3 patients survived. Mean follow-up was 8.4 months (range: 1.2-16.6). All remain with a 100% primary patency rate. CONCLUSION: Retrograde open mesenteric stenting for acute mesenteric ischemia is a viable alternative to bypass.

Successful repair of a ruptured Stanford type B aortic dissection during pregnancy.

We present our experience with an acute Stanford type B aortic dissection in a 25-year-old, 26-week gravid patient without a known connective tissue disorder and discuss a literature-based treatment strategy. After failed conservative treatment manifest by aneurysm rupture, emergency cesarean section delivery and immediate repair of her thoracic aorta was performed. Seven months later, she is fully caring for her healthy baby. During pregnancy, thoracic aortic dissection occurs from physiologic and hemodynamic changes. Emergency cesarean delivery, followed by immediate aortic repair, is the treatment choice if malperfusion syndrome, rupture, uncontrolled hypertension, or unremitting pain occurs.

Spontaneous superior mesenteric artery (SMA) dissection: an unusual cause of abdominal pain.

A 44-year-old woman presented to our Emergency Department with a 4-day history of severe, sharp left upper quadrant abdominal pain associated with nausea and vomiting. She had been seen 3 days prior at another Emergency Department, and had a negative work-up including a normal non-contrast computed tomography (CT) scan of the abdomen/pelvis for possible kidney stone. Vital signs were: temperature 36.3°C (97.3°F), pulse 100 beats/min, respiratory rate 18 breaths/min, and blood pressure 141/80 mm Hg. Physical examination was remarkable for marked tenderness in the left upper and middle quadrants and voluntary guarding. Bowel sounds were normal. Although laboratory studies were normal, a CT scan of the abdomen/pelvis with intravenous contrast suggested a superior mesenteric artery dissection. This was confirmed with arteriography. The clinical presentation, diagnostic evaluation, and management of superior mesenteric artery dissection are reviewed.

Endoleak after endovascular aneurysm repair: duplex ultrasound imaging is better than computed tomography at determining the need for intervention.

OBJECTIVE: Color duplex ultrasound (CDU) imaging is a noninvasive alternative to computed tomography (CT) for the detection of endoleak. This study compared CT and CDU imaging in the detection of endoleaks requiring intervention after endovascular aneurysm repair (EVAR). METHODS: All EVARs performed at our institution from 1996 to 2007 were retrospectively reviewed. CDU and CT scans < or =3 months were paired and the presence of an endoleak and its type were recorded. Clinical follow-up was reviewed and interventions for endoleak were recorded. Interventions were performed for type I, for type II with sac enlargement, and for type III endoleaks. The first analysis of clinical test outcomes used the findings of CT scan as a gold standard and the second used the findings at time of intervention as a gold standard. RESULTS: During the time period reviewed, 496 patients underwent EVAR, and 236 of these had CDU and CT follow-up studies paired < or =3 months of each other. Mean follow-up was 17 months (range, <1-111 months). We reviewed 944 studies or 472 pairs. Eighteen patients (7.6%) required intervention for 19 endoleaks: six type I, 11 type II, and two type III. Early endoleak (< or =1 month) requiring reintervention was detected in 1 vs late endoleak (mean, 28 months; range, 0.6-88 months) in 18. All type I and III endoleaks were treated with endovascular cuff or limb extension placement. Three type II endoleaks were treated with open ligation, and coil or glue embolization was used in eight. CDU imaging detected endoleaks requiring intervention in 89% of cases, whereas CT detected endoleak in 58% (P < .05). The ability to correctly identify the type of endoleak as confirmed at time of intervention was 74% with CDU imaging vs 42% by CT (P < .05). CDU, for the detection of endoleak requiring intervention, had a sensitivity of 90%, specificity of 81%, negative predictive value (NPV) of 99%, and positive predictive value (PPV) of 16%, while CT had a sensitivity of 58%, specificity of 87%, NPV of 98%, and PPV of 15%. CONCLUSIONS: CDU imaging has a high sensitivity in detecting endoleaks requiring intervention, is better at identifying the type of endoleak, and is an excellent test for graft surveillance after endovascular aneurysm repair. Compared with CT scan, CDU imaging in our experience is the preferred test on which to base an intervention for endoleak.

Management of hypertension in the elderly patient.

Hypertension in the elderly is associated with increased occurrence rates of sodium sensitivity, isolated systolic hypertension, and 'white coat effect'. Arterial stiffness and endothelial dysfunction also increase with age. These factors should be considered in selecting antihypertensive therapy. The prime objective of this therapy is to prevent stroke. The findings of controlled trials show that there should be no cut-off age for treatment. A holistic program for controlling cardiovascular risks should be fully discussed with the patient, including evaluation to exclude underlying causes of secondary hypertension, and implementation of lifestyle measures. The choice of antihypertensive drug therapy is influenced by concomitant disease and previous medication history, but will typically include a thiazide diuretic as the first-line agent; to this will be added an angiotensin inhibitor and/or a calcium channel blocker. Beta blockers are not generally recommended, in part because they do not combat the effects of increased arterial stiffness. The hypertension-hypotension syndrome requires case-specific management. Drug-resistant hypertension is important to differentiate from faulty compliance with medication. Patients resistant to third-line drug therapy may benefit from treatment with extended-release isosorbide mononitrate. A trial of spironolactone may also be worthwhile.

Should fistulas really be first in the elderly patient?

BACKGROUND: The Kidney Disease Outcomes and Quality Initiative (K/DOQI) has developed guidelines from available data suggesting that arteriovenous fistulas (AVF) be performed in the majority of patients. Patient demographics were not included nor suggested in their recommendations. The purpose of this study is to analyze the outcomes of elderly patients, age greater than 70, undergoing first-time permanent access surgery. METHODS: A retrospective review of consecutive patients undergoing new, first time access procedures from January 2005 through December 2005 was performed. Patients with previous attempts at permanent Arteriovenous (AV) access were removed from analysis. Standard statistical methods were used and patency was determined with Kaplan-Meier curves. RESULTS: One hundred and sixty eight patients underwent first time AVF, 48 of whom were older than 70 years of age. Comparing elderly patients to younger ones, the 12 month primary assisted patency was 35% and 67%, respectively (p=0.002) and secondary patency was 36% and 67%, respectively (p=0.004). Of the 48 elderly patients, 48% had died in the subsequent follow up period as compared to just 20% of the 120 patients younger than 70. The 18-month survival for the elderly group was 50% versus 74% for the younger patients (p=0.004). Of the elderly group who died, the average time to death was 13.1 months and only 8 AVF were able to be accessed. Similar intervention rates per year were seen in both groups. DISCUSSION: With an aging population, more patients older than 70 are being evaluated for permanent vascular access. This group poses a difficult dilemma for surgeons attempting to adhere to K/DOQI guidelines. In light of the increased mortality and decreased patency of AVF, this data questions which form of permanent access should be first-line treatment in this subgroup of patients. CONCLUSION: This data suggest in the elderly patients, autogenous fistulas may not be the best option for this set of patients.

Selective stenting in subintimal angioplasty: analysis of primary stent outcomes.

OBJECTIVE: Subintimal angioplasty (SIA) is being increasingly utilized to treat chronic arterial occlusions. The role of stents in SIA is currently unknown. We performed a retrospective review of selective stent use in SIA to assess outcomes and factors affecting these results. METHODS: A retrospective review of patient information--including demographics, indications, procedures, noninvasive studies, and post-procedural events--was performed on our database for patients undergoing SIA in the superficial femoral and popliteal arteries. Outcomes were calculated only on technically successful SIAs using Kaplan-Meier survival analysis. Continuous and non-continuous data were compared using the Student t test and the z test, respectively. Survival curves were compared using log-rank testing for univariate analysis and Cox hazard-regression analysis for multivariate analysis. RESULTS: Three-hundred-sixty-eight patients (382 limbs) underwent femoral and/or popliteal SIA for critical limb ischemia or disabling claudication from December 1, 2002 through July 31, 2006. Eighty-four limbs (22%) had a stent placed, while 298 (78%) did not receive a stent. Mean follow-up was 11.7 months (range, 0-45 months). One-year primary and secondary patency for stent vs no-stent group was 50% vs 45% (P = .73) and 70% vs 78% (P = .47), respectively. One-year limb salvage rate for the stent vs no-stent group was 85% vs 90% (P = .61). At 2 years, patients receiving a stent are more likely to undergo open bypass than those without a stent (P = .06). Eighty-three patients underwent 84 SIA with stent placement. The mean number of stents for each case was 1.4 +/- 0.7. Univariate analysis revealed that previous ipsilateral bypass surgery significantly decreased 1-year patency: 35% vs 56% (P = .05). SIA performed for disabling claudication had a trend toward improved 1-year patency 58% vs 39% for critical limb ischemia (P = .09). A stent diameter > or =7 mm displayed a trend toward better patency 53% vs 37% for diameter < or =6 mm (P = .08). None of these factors proved significant with multivariate analysis. CONCLUSION: Selective stents placed for suboptimal results after subintimal angioplasty produce similar patency rates to primary SIA without stents. Patients receiving stents with prior lower extremity bypass surgery will have worse outcomes than those without. Use of a stent diameter < or =6 mm and indication of critical limb ischemia will likely produce worse results. It appears that other stent variables (location, number, length, and overlap) do not alter patency. Finally, selective stent use after SIA provides excellent limb salvage.

Treatment of isolated systolic hypertension.

Isolated systolic hypertension (ISH) is the dominant form of hypertension in the elderly. It is associated with increased arterial pulse pressure, to which an early-returning and magnified pulse-wave reflection makes an important contribution. Treatment of ISH with diuretics, calcium channel blockers (CCBs), and angiotensin II inhibitors is effective in reducing systolic blood pressure, preventing cardiovascular morbid events, and lowering mortality; these agents may have to be used in combination to achieve the systolic blood pressure goal of < 140 mm Hg. Treatment with beta-blockers appears to be less effective. The relative efficacy of various classes of antihypertensive drugs for lowering pulse pressure and systolic blood pressure is determined in part by their differing abilities to reduce pulse-wave reflection. In patients with ISH that is refractory to dual or triple therapy, measurement of the reflected wave by applanation tonometry may be useful in determining which additional antihypertensive agent to use.

Nitrates as adjunct hypertensive treatment.

Isolated systolic hypertension (ISH) is an important cause of strokes and heart failure among the elderly, but it is difficult to control in some elderly patients, even with combination antihypertensive therapy. The presence of a prominent reflection wave in the arterial pulse-wave profile of such patients signifies that adjuvant nitrate therapy may prove effective in lowering pulse pressure. This reflection arises in the muscular arteries and is caused by arterial stiffness associated with hypertension and other cardiovascular risk factors, probably including endothelial dysfunction. By acting directly on the arterial wall, nitrates produce endothelium-independent vasorelaxation. The reflection wave and the contribution this makes to pulse pressure are thereby ablated. Controlled trials of the use of isosorbide mononitrate and isosorbide dinitrate in ISH have shown that these agents decrease systolic blood pressure as well as pulse pressure, and with the mononitrate, efficacy appears to be unimpaired by nitrate tolerance.

Long-term effectiveness of extended-release nitrate for the treatment of systolic hypertension.

Isosorbide mononitrate (ISMN) is effective in the short-term for decreasing systolic blood pressure, pulse pressure, and pulse wave reflection in patients with systolic hypertension. To determine whether tolerance negates the efficacy of this nitrate in the long-term, a placebo-controlled study was performed in which ISMN was withdrawn briefly in a group of patients (n=16) who had received extended-release ISMN 60 to 120 mg once daily for 16 to 109 months. Blood pressure and wave reflection were determined by 24-hour ambulatory recorder and tonometer, respectively. During a 4-hour delay of the regular morning dose of ISMN, mean systolic blood pressure was higher than with the regular ISMN dosing schedule (P<0.0001). The maximum placebo-active difference was 16+/-4 mm Hg. The corresponding difference in augmentation index (a measure of pulse wave reflection) corrected for heart rate was 25+/-4% (P<0.001). The difference in pulse pressure was 13+/-3 mm Hg (P<0.001). There was no significant difference in diastolic blood pressure. For a subgroup (n=12) in which the effects of a single ISMN dose had been determined at the initiation of regular ISMN therapy, the mean change in augmentation index was of similar magnitude to that observed in their initial study. Thus, tolerance does not seriously diminish the antihypertensive efficacy of ISMN used as adjunct therapy in the chronic treatment of systolic hypertension. This agent lowers systolic blood pressure sufficiently to achieve therapeutic goal in some patients refractory to conventional treatment regimens.

Is three-dimensional computed tomography reconstruction justified before endovascular aortic aneurysm repair?

OBJECTIVES: The endovascular management of abdominal aortic aneurysm (AAA) relies on accurate preoperative imaging for proper patient selection and operative planning. Three-dimensional (3-D) computed tomography (CT) with reformatted images perpendicular to blood flow has gained popularity as a method of AAA assessment and image-based planning before endovascular aneurysm repair (EVAR). The current study was undertaken to determine the interobserver agreement of AAA measurements obtained with axial CT and reformatted 3-D CT and to compare the consistency of the 2 methods in selecting patients for EVAR. METHODS: Eight observers assessed the axial CT and reformatted 3-D CT scans for 5 patients with AAAs to determine whether the patients were candidates for EVAR. 3-D CT with multiplanar reformatted images was performed by Medical Media Systems (MMS). Each observer measured the length and diameter of the proximal neck, maximal AAA, aortic bifurcation, common iliac diameter, and aortic angulation. The proximal neck and common iliac arteries were also assessed for thrombus, calcification, and tortuosity. Agreement of the measurements on axial CT scans was compared with those on MMS CT scans by calculating the kappa statistic. Complete agreement was defined as kappa = 1.0. The limits of agreement between observers were also calculated. RESULTS: The cumulative interobserver agreement of MMS CT scans (kappa =.81) was greater than for axial CT scans (kappa =.59). The kappa value for each of the diameter measurements was greater with the MMS CT scans. In 79% of cases the observers' measurements were less than 2 mm from the mean with MMS CT, compared with 59% for axial CT. The kappa value for deciding whether a patient was an endograft candidate on the basis of aortic neck was greater with the MMS CT (0.92 vs 0.63). The limits of agreement between observers were also better with the MMS CT. CONCLUSIONS: The interobserver agreement in planning EVAR is significantly better with MMS CT compared with traditional axial CT. The routine use of MMS CT appears justified before EVAR to improve the accuracy and consistency of patient selection.

Systolic hypertension in the elderly: pushing the frontiers of therapy--a suggested new approach.

In elderly patients with systolic hypertension resistant to treatment with conventional therapy, increased aortic pulse wave reflection and a high augmentation index are often present. These findings are indicative of endothelial dysfunction and deficient generation of nitric oxide, a potent vasodilator in the arterial tree. In such patients, treatment with the nitric oxide donor extended-release isosorbide mononitrate characteristically produces prompt and sustained falls in both pulse wave reflection and systolic blood pressure. The adjunct use of this nitrate produces useful additional decreases in systolic blood pressure ranging from 10 to 45 mm Hg, often achieving target blood pressure goals in isolated systolic hypertension. By combining this endothelium-independent nitric oxide donor with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, the potential exists to address both the nitric oxide deficiency and endothelial dysfunction of the vascular endothelium in these patients. Other possibilities for synergism with this combination include complementary hemodynamic, circadian, and metabolic actions together with prevention of nitrate tolerance. Isosorbide mononitrate may also be used successfully with calcium channel blockers, beta blockers, and diuretics.

Percutaneous treatment of symptomatic central venous stenosis [corrected].

OBJECTIVES: The increased use of central venous access primarily for hemodialysis has led to a significant increase in clinically relevant central venous occlusive disease (CVOD). The magnitude of and the optimal therapy for CVOD are not clearly established. The purpose of this study is to define the problem of CVOD and determine the success of percutaneous therapy for relieving symptoms and maintaining central venous patency. METHODS: Patients presenting with disabling upper-extremity edema suggestive of central venous stenosis or occlusion during a 3-year period were evaluated by venography of the upper extremity and central veins. Percutaneous venous angioplasty (PTA) and/or stent placement was performed as clinically indicated. The success of therapy was assessed, and the patients were observed to determine the incidence of recurrence and additional procedures. Recurrent lesions underwent similar evaluation and treatment. RESULTS: A total of 32 sides were treated in 29 patients with a mean of 1.9 interventions per side treated. Hemodialysis-related lesions were the underlying cause in 87% with the remaining 13% related to previous central venous catheterization. The lesions involved the axillary, subclavian, and innominate veins with complete venous occlusion in six (19%) cases. Percutaneous angioplasty was followed by stent placement in six (19%) cases. The procedure was a technical success and was performed without complications in all cases (100%). Mean follow-up was 16.5 months (range, 4-36 months). On average, patient symptoms were controlled for 6.5 months after the initial intervention. Recurrent edema led to additional PTA in 20 (63%) cases. Fifty percent (n = 14) of patients with an arteriovenous fistula (AVF) experienced recurrent symptoms after initial and/or repeat PTA and required AVF ligation. Complete resolution after the initial PTA was predictive of long-term success. CONCLUSIONS: Central venous occlusive disease has emerged as a significant clinical problem. Percutaneous venous angioplasty can provide temporary symptomatic relief; however, multiple procedures are often required and long-term relief is rarely achieved.

Interactions of L-arginine, isosorbide mononitrate, and angiotensin II inhibitors on arterial pulse wave.

BACKGROUND: Deficiency of nitric oxide (NO) production has been implicated in the pathogenesis of increased pulse wave reflection associated with systolic hypertension. We investigated the effects on systolic blood pressure (BP) and pulse wave contour of two nitrate donors, isosorbide mononitrate (ISMN) and L-arginine. METHODS: The subjects were 14 elderly patients chronically treated with antihypertensive agents. In seven of the subjects, agents causing angiotensin II (AII) inhibition (angiotensin-converting enzyme [ACE] inhibitor or AT(1) receptor antagonist, or both) were used. Study entry required systolic BP of 150 to 200 mm Hg, and aortic pulse wave augmentation more than 15 mm Hg. Pharmacodynamic responses to ISMN, L-arginine, and ISMN plus L-arginine, were assessed in double-blind crossover studies by standard sphygmomanometry and applanation tonometry. RESULTS: Peripheral systolic BP, aortic systolic BP, and the aortic augmentation index were decreased (P <.001) by ISMN, irrespective of AII inhibition. L-arginine enhanced these effects (P <.001) in the subjects without AII inhibition, but not in those receiving AII inhibitors. Given without ISMN or AII inhibitors, L-arginine decreased peripheral systolic BP, but to a lesser extent than ISMN. CONCLUSIONS: L-arginine has potential value as an adjunct to ISMN in combination with antihypertensive therapy in elderly patients with systolic hypertension. However, when given with single-dose ISMN, its vasodilator activity may overlap with that of AII inhibitors. Future studies of L-arginine in conjunction with chronic continuous ISMN dosing are warranted.

Effects of isosorbide mononitrate and AII inhibition on pulse wave reflection in hypertension.

The aortic pulse wave contour in isolated systolic hypertension often shows a prominent reflection peak, which combines with the incident wave arising from cardiac ejection so as to widen pulse pressure. We investigated the effects of an extended-release nitrate preparation and of 2 angiotensin II (AII) inhibitors (an AII receptor antagonist and an ACE inhibitor) on the aortic pulse wave contour and systemic blood pressure in hypertensive subjects with high augmentation index caused by exaggerated pulse wave reflection. Two double-blind, randomized, placebo-controlled crossover studies were carried out in a total of 16 elderly patients with systolic hypertension resistant to conventional antihypertensive therapy. In 1 study, pharmacodynamic responses to single doses of placebo, isosorbide mononitrate, eprosartan, and captopril were determined; in the other, single-dose isosorbide mononitrate and placebo were compared in subjects treated with AII inhibitors at baseline. Blood pressure was measured by sphygmomanometry and pulse wave components by applanation tonometry at the radial artery. All 3 agents were shown to decrease brachial systolic blood pressure, aortic systolic blood pressure, and aortic pulse pressure. Qualitative effects on the aortic pulse wave contour differed: augmentation index was not significantly altered by either captopril or eprosartan but was decreased (P<0.0001) by approximately 50% of the placebo value with isosorbide mononitrate in both study groups. We propose that isosorbide mononitrate corrected the magnified wave reflection in systolic hypertension of these elderly patients by an effect that was distinct from that exercised by either acute or chronic AII inhibition.