A lamb in wolff's clothing.
A symptomatic woman with an electrocardiogram (ECG)-based diagnosis of Wolff-Parkinson-White (WPW) syndrome underwent electrophysiologic studies that revealed a likely fasciculo-ventricular tract.
Diagnosis, Differential↗
Biomedical subjects
Daniel Katz
Publications and source records attributed to Daniel Katz.
Monthly access flow monitoring with increased prophylactic angioplasty did not improve fistula patency.
BACKGROUND: Regular access monitoring is recommended to detect and treat access stenosis in order to prevent access thrombosis and failure. METHODS: In 1999, we instituted monthly access blood flow monitoring using the ultrasound dilution technique (UDT). In a sequential observational trial, 222 patients were studied for the impact of UDT monitoring on patency of their first arteriovenous autogenous fistula. Group 1, the historic group (before 1999), had 146 arteriovenous fistulas (50.7% upper arm), followed for 259 access-years. Group 2, the UDT-monitored group, had 76 arteriovenous fistulas (60.5% upper arm), followed for 123 access-years. Decision to refer for angiography was based on clinical criteria for group 1, and clinical criteria plus results of UDT flow monitoring in group 2. RESULTS: Cumulative patency was longer (P < 0.01) and the thrombosis rate was lower (P < 0.05) in group 2. However, the improvement occurred prior to initiation of UDT flow monitoring. Comparing outcomes in group 2 patients whose fistula survived to start flow monitoring with group 1 patients whose fistula survived at least 160 days (the median time to starting UDT monitoring in group 2), there was a sevenfold increase in angioplasty procedures (0.67 vs. 0.09 per access-year) but no improvement in the thrombosis rate or cumulative fistula patency. CONCLUSION: UDT monitoring increased the rate of angioplasty procedures and thereby shortened primary unassisted patency, but did not decrease the thrombosis rate or improve cumulative fistula patency.
Angioplasty↗
Limb salvage after infrainguinal bypass graft failure.
OBJECTIVE: The purpose of this study was to examine the outcome of patients in whom an infrainguinal bypass graft failed. METHODS: This was a retrospective analysis of consecutive patients undergoing infrainguinal bypass grafting in a single institution over 8 years. RESULTS: Six hundred thirty-one infrainguinal bypass grafts were placed in 578 limbs in 503 patients during the study period. The indication for surgery was limb-threatening ischemia in 533 patients (85%); nonautologous conduits were used in 259 patients (41%), and 144 (23%) were repeat operations. After a mean follow-up of 28 +/- 1 months (median, 23 months; range, 0-99 months), 167 grafts (26%) had failed secondarily. The rate of limb salvage in patients with graft failure was poor, only 50% +/- 5% at 2 years after failure. The 2-year limb salvage rate depended on the initial indication for bypass grafting: 100% in patients with claudication (n = 16), 55% +/- 8% in patients with rest pain (n = 49), and 34% +/- 6% in patients with tissue loss (n = 73; P <.001). The prospect for limb salvage also depended on the duration that the graft remained patent. Early graft failure (<30 days; n = 25) carried a poor prognosis, with 2-year limb salvage of only 25% +/- 10%; limb salvage was 53% +/- 5% after intermediate graft failure (<2 years, n = 110) and 79% +/- 10% after late failure (>2 years, n = 15; P =.04). Multivariate analysis revealed shorter patency interval before failure (P =.006), use of warfarin sodium (Coumadin) postoperatively (P =.006), and infrapopliteal distal anastomosis (P =.01) as significant predictors for ultimate limb loss. CONCLUSION: The overall prognosis for limb salvage in patients with failed infrainguinal bypass grafts is poor, particularly in patients with grafts placed because of tissue loss and those with early graft failure.
Aged↗
Degree of carotid plaque calcification in relation to symptomatic outcome and plaque inflammation.
OBJECTIVE: We undertook this study to quantitate differences in the degree of calcification between symptomatic and asymptomatic plaques removed at carotid endarterectomy (CEA) and to determine associated extent of plaque macrophage infiltration, a histopathologic feature of plaque instability. METHODS: CEA plaques (n = 48) were imaged at 1.25-mm intervals with spiral computed tomography (CT; 10-15 images per plaque). Indications for CEA were transient ischemic attack (n = 16), stroke (n = 5), amaurosis (n = 4), and critical asymptomatic stenosis (n = 23). The percent area calcification for each plaque was determined in spiral CT serial sections and averaged for each plaque. In 31 of 48 plaques macrophage infiltration was quantitated in corresponding histologic sections with immunohistochemical techniques. RESULTS: The mean (+/- SD) age of patients with symptomatic and asymptomatic plaques was 66 +/- 7 years vs 71 +/- 7 years, respectively, and degree of stenosis was 76% versus 82%, respectively (P =.05). Atherosclerosis risk factors were similar between groups. Percent plaque area calcification was twofold greater in asymptomatic versus symptomatic plaques (48% +/- 19% vs 24% +/- 20%, respectively; P <.05). At receiver operating characteristic curve analysis, 80% of symptomatic plaques were below and 87% of asymptomatic plaques were above a cutoff point of 30% plaque area calcification. Macrophage burden was greater in the symptomatic plaques than in the asymptomatic plaques (52% vs 23%; P <.03). A strong inverse relationship between the degree of plaque calcification and macrophage infiltration was found in critical carotid stenoses (r = -0.87; P <.001). CONCLUSIONS: Symptomatic plaques are less calcified and more inflamed than asymptomatic plaques. Regardless of clinical outcome, a strong inverse correlation was found between the extent of carotid plaque calcification and the intensity of plaque fibrous cap inflammation as determined by the degree of macrophage infiltration. Carotid plaque calcification is associated with plaque stability, and is a potential spiral CT in vivo quantitative marker for cerebrovascular ischemic event risk.
Aged↗
Imaging of an accessory spleen presenting as a slow-growing mass in the transplanted pancreas.
Explore the source record for details and available documents.
Choristoma↗
Does variant hepatic artery anatomy in a liver transplant recipient increase the risk of hepatic artery complications after transplantation?
OBJECTIVE: Our aim was to determine whether variant hepatic artery anatomy in a liver transplant recipient increases the risk of hepatic artery complications after liver transplantation. MATERIALS AND METHODS: The study group consisted of 84 patients who underwent gadolinium-enhanced 3D MR angiography before orthotopic liver transplantation in which a branch patch arterial anastomosis at the gastroduodenal takeoff was used. MR angiography studies were retrospectively reviewed and assessed for the presence and type of variant hepatic artery anatomy. The diameter of the distal common hepatic artery was measured. The incidence of posttransplantation hepatic artery stenosis or thrombosis was assessed. RESULTS: Seven (8.3%) of the 84 patients developed hepatic artery complications after transplantation. Of the 24 patients with variant hepatic artery anatomy, five (20.8%) had posttransplantation/ hepatic artery complications. In contrast, only two (3.3%) of the 60 patients with classic hepatic artery anatomy had complications. The higher complication rate in patients with variant hepatic artery anatomy was statistically significant (p < 0.05). The odds ratio was 7.6 (95% confidence interval, 1.4-42.6). The diameter of the distal common hepatic artery was smaller in patients with variant hepatic artery anatomy compared with those with classic hepatic artery anatomy (range, 4.3-7.1 mm [mean, 5.8 mm] vs 4.0-8.9 mm [mean 6.3 mm], p < 0.05), and it was also smaller in patients who had posttransplantation hepatic artery complications compared with those who had no complications (range, 4.2-6.3 mm [mean, 5.2 mm] vs 4.0-8.9 mm, [mean, 6.2 mm], p < 0.01). CONCLUSION: Variant hepatic artery anatomy in a liver transplant recipient increased the risk of hepatic artery complications after transplantation. The smaller caliber of the native common hepatic artery may contribute to the higher risk.
Adolescent↗
Redo infrainguinal bypass: factors predicting patency and limb salvage.
The increased complexity of redo infrainguinal bypass procedures can result in prolonged operative time and increased morbidity. This review was undertaken to compare outcomes from primary and redo bypass procedures and to identify factors predictive of graft failure and limb loss after redo bypass. All infrainguinal bypasses ( n = 468) from 1995 to 1999 were reviewed. A total of 367 primary bypasses in 317 patients were compared to 101 redo grafts in 84 patients with previously failed bypasses. Risk factors and types of procedures were compared using Student's t-test and the chi(2) test. Patency and limb salvage were compared using life-table analysis. Patients requiring redo bypasses were less likely to have diabetes and end-stage renal disease. Two-year patency (66 +/- 4% primary vs. 55 +/- 7% redo, p = 0.13) and limb salvage (75 +/- 3% primary vs. 72 +/- 6% secondary, p = 0.43) were comparable between primary and redo bypass groups. Female gender was predictive of redo graft failure (2-year patency 73 +/- 8% male vs. 39 +/- 9% female, p = 0.01). Clinical indications that predicted failure of a redo bypass included thrombosis of an autologous graft (1-year patency 71 +/- 7% previous prosthetic vs. 49 +/- 10% previous autologous, p = 0.004), thrombosis of an infrageniculate bypass (2-year patency 65 +/- 10% suprageniculate vs. 46 +/- 9% infrageniculate, p = 0.044), and a limb salvage indication for the primary operation (2-year patency 86 +/- 9% claudication vs. 44 +/- 8% limb salvage, p = 0.008). When a primary bypass fails despite the use of optimal conduit (autologous vein) and an infrageniculate target vessel, the redo bypass has a higher risk of failure, particularly in female patients. Nonetheless, patency and limb salvage rates justify an attempt at revascularization after failed primary bypass.
Aged↗
Long-term outcome of infrainguinal bypass grafting in patients with serologically proven hypercoagulability.
OBJECTIVE: The purpose of this study was to test the hypothesis that the long-term outcome of infrainguinal bypass grafting in patients with congenital or acquired hypercoagulability is inferior to the results in patients without documented clotting disorders. METHODS: The study was a retrospective analysis of consecutive patients from January 1994 to January 2001. RESULTS: Five hundred eighty-two infrainguinal bypass grafts were created in 456 patients. Indication for surgery was limb-threatening ischemia in 84%; prosthetic conduits were implanted in 38%. Seventy-four grafts were created in 57 patients with one or more serologically proven hypercoagulable states, including heparin-induced platelet aggregation (n = 37), anticardiolipin antibodies (n = 11), lupus anticoagulant (n = 8), protein C or S deficiency (n = 7), antithrombin III deficiency (n = 3), and factor V Leiden mutation (n = 1). Patients with hypercoagulability were younger (63 +/- 2 years versus 69 +/- 1 years; P =.007), more likely to have undergone prior revascularization attempts (38% versus 21%; P =.003), and more likely to have chronic anticoagulation therapy after surgery (46% versus 25%; P =.001). After 5 years (median follow-up, 19 months), patients with hypercoagulability had poorer primary patency (28% +/- 7% versus 35% +/- 5%; P =.004), primary assisted patency (37% +/- 7% versus 45% +/- 6%; P =.0001), secondary patency (41% +/- 7% versus 53% +/- 6%; P =.0001), limb salvage (55% +/- 8% versus 67% +/- 6%; P =.009), and survival (61% +/- 8% versus 74% +/- 4%; P =.02) rates. Multivariate analysis identified only prosthetic conduit choice (P =.0001), hypercoagulability (P =.0003), and limb salvage indication (P =.01) as independent predictors of graft failure. CONCLUSION: Patients with serologically proven hypercoagulability have inferior long-term patency, limb salvage, and survival rates after infrainguinal bypass. The high prevalence rate (13%) of diverse hypercoagulable states in this patient population supports serologic screening, especially in referral practices.
Aged↗
Dose-adjusted cyclosporine c2 in a patient with jejunoileal bypass as compared to seven other liver transplant recipients.
Jejunoileal bypass (JIB) is a weight loss procedure in which malabsorption is produced by connecting a short length of proximal jejunum to the distal ileum. Because 90% of the small intestine is bypassed, it may have impact on the dose-concentration response of oral cyclosporine (CsA). The authors characterized the dose-adjusted blood concentrations of CsA obtained 2 hours (C2) after oral microemulsion CsA (ME-CsA) in a liver transplant (LTx) subject with an intact JIB, as compared with those from seven LTx controls without JIB. The biliary reconstruction involved choledochocholedochostomy without external drainage in all patients. ME-CsA was administered via a nasogastric tube within 24 hours after graft reperfusion. Oral fluconazole was given prophylactically to the study subject only for 6 days after LTx. During the first week after LTx, the dose-adjusted C2 (mean +/- SD) for the study subject and for controls was 53 +/- 10 and 106 +/- 47 ng/mL, respectively (P < 0.001). The corresponding value during the period from day 7 to day 107 was 105 +/- 40 and 257 +/- 86 ng/mL, respectively (P < 0.001). Multiple linear regression revealed that dosage, days after LTx, and the presence of a JIB were all independent predictors of C2 (R2 = 0.798, P = 0.037). Lack of bile resulting in malabsorption of ME-CsA was not thought to be significant contributor to her low dose-adjusted C2 because there was no external bile drainage and a portion of terminal ileum, where most bile acid reabsorption occurred, was still available after JIB. The fact that fluconazole failed to increase the dose-adjusted C2 in the study subject supports that enteric clearance of CsA may become clinically unimportant after JIB. Therefore, the low dose-adjusted C2 is most likely explained by the reduced bowel length and associated absorptive surface area after JIB. In conclusion, patients with JIB may require higher doses of ME-CsA.
Biological Availability↗
Long-term results of infrageniculate bypass grafting using all-autogenous composite vein.
Infrageniculate (below-knee) bypass using all-autogenous composite vein requires multiple incisions, venovenostomy, and prolonged operating time. The purpose of this study was to evaluate the long-term results of this procedure, with comparisons to grafts created from single-segment greater saphenous vein (GSV) or polytetrafluoroethylene (PTFE). A total of 362 consecutive infrainguinal bypass grafts with infrageniculate distal target arteries were created in 283 patients in a single institution between January 1995 and December 2000. Comorbid conditions were common, including diabetes (58%), coronary artery disease (56%), prior lower extremity revascularization (41%), end-stage renal failure (20%), and prior coronary artery bypass grafting (18%). The indication for revascularization was limb salvage in 93% of cases. The grafts were constructed from single segments of GSV (n = 239), from two or more vein segments resulting in an all-autogenous composite graft (n = 61), or from PTFE (n = 62). All-autogenous composite grafts were constructed using segments of ipsilateral or contralateral GSV (n = 49), upper extremity vein (n = 23), superficial femoral vein (n = 7), or lesser saphenous vein (n = 5). Infrageniculate all-autogenous composite vein grafts exhibited similar long-term results to those of GSV grafts, and far superior results to those of PTFE grafts. For patients with available autogenous segments, the all-autogenous composite vein graft is the conduit of choice.
Aged↗
Conduit choice for above-knee femoropopliteal bypass grafting in patients with limb-threatening ischemia.
Many surgeons consider PTFE to be the conduit of choice for above-knee femoropopliteal bypass grafting, since PTFE is relatively easy to implant and spares autogenous saphenous vein (ASV) for subsequent peripheral or coronary artery bypass grafting (CABG). This practice has recently been challenged, as some studies have suggested that ASV may exhibit superior patency in certain patient subgroups. The purpose of this retrospective study was to examine the contemporary outcome of above-knee femoropopliteal bypass grafting in patients with limb-threatening ischemia. Between January 1995 and December 2000, 159 above-knee femoropopliteal bypass grafts were created for limb-threatening ischemia (rest pain or tissue loss). There was a high incidence of comorbid illness, including open foot wounds at the time of operation (62%), hypertension (58%), coronary artery disease (53%), diabetes mellitus (36%), cerebrovascular disease (23%), prior contralateral bypass or amputation (21%), disadvantaged or "blind" outflow (19%), prior ipsilateral bypass (14%), prior CABG (11%) end-stage renal failure (7%). The use of PTFE predominated (n = 11), with a minority of grafts comprising single-segment ipsilateral or contralateral ASV (n = 18). Although the small number of patients undergoing ASV grafting limited the statistical power of comparison, our results suggest that above-knee ASV performs better than PTFE in patients with limb-threatening ischemia.
Aged↗
An attempt to decrease ammonia levels after portacaval anastomosis in dogs: hepatic periarterial neurectomy.
Hepatic encephalopathy and elevated serum ammonia levels occur commonly after portacaval shunt and are hypothesized to be, in part, due to decreased hepatic blood flow. Prior work has demonstrated increased blood flow to the liver following hepatic periarterial neurectomy. In this experimental study, we investigated the functional, hemodynamic, and histopathological changes in the liver and kidney occurring after the addition of hepatic periarterial neurectomy to side-to-side portacaval shunt in dogs. It is our hypothesis that the addition of hepatic periarterial neurectomy to portacaval shunt will decrease postshunt ammonia levels. Side-to-side portacaval shunt was performed in 12 dogs (group I). Hepatic periarterial neurectomy was added to portacaval shunt in 9 dogs (group II). Serum levels of ammonia, urea, creatinine, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, albumin, and bilirubin together with hepatic blood flow were determined in both groups preoperatively and on postoperative day 21. The pre- and postoperative histopathologic changes of the liver and kidney were evaluated. There was significantly less postoperative elevation of serum ammonia and aspartate aminotransferase when hepatic periarterial neurectomy was added to the portacaval shunt procedure. Hemodynamic studies of hepatic artery and hepatic tissue indicated better blood flow in group II. The histopathologic evaluation of group II showed expansion of sinusoids, portal vessels, and portal areas and increased portal fibrosis as compared to group I. The results of this experimental study show that adding hepatic periarterial neurectomy to the portacaval shunt procedure improves postoperative serum levels of ammonia and aspartate aminotransferase and hepatic artery and tissue blood flow.
Ammonia↗