Tomographic three-dimensional ultrasound imaging improves spatial visualization and management of varicose veins.

Tomographic three-dimensional ultrasound using handsfree electromagnetic tracking is an important adjunct to traditional two-dimensional duplex ultrasound examination. This technique allows vascular surgeons to better orientate and visualize the often complex anatomy along the entire length of the target vein. This paper reports a novel technique in preoperative and postoperative acquisition of superficial incompetent veins, thereby providing a comprehensive three-dimensional orientation of different pathological patterns of incompetence.

Risk Factor Analysis and Long-Term Outcomes in Patients with Endovascular Revascularization for Intermittent Claudication or Chronic Limb-Threatening Ischemia.

BACKGROUND: The aim of this study is to review long-term outcome and identify risk factors for patients with peripheral arterial disease (PAD) with percutaneous transluminal angioplasty/stent as a primary treatment strategy for intermittent claudication (IC) or chronic limb-threatening ischemia (CLTI). METHODS: A retrospective cohort study with data collected prospectively from Clinical Data Analysis and Reporting System, departmental database, and Clinical Management System. All patients who underwent endovascular procedures for PAD between January 2011 and December 2020 were identified. The primary outcomes are overall survival and amputation-free survival. Predictive factors for OS and AFS were determined using Cox Model. RESULTS: A total number of 640 patients with PAD (IC, n = 243; CLTI, n = 377) underwent endovascular percutaneous transluminal angioplasty/stenting for PAD from January 2011 to December 2020. Patients with CLTI had a significantly higher 30 days readmission rate (18.8% vs. 6.5%, P < 0.001), emergency reoperation within 30 days (3.4% vs. 0%, P = 0.002), and death within same admission (2.7% vs. 0%, P = 0.008) compared to IC patients. The overall survival and amputation-free survival rates were significantly lower in CLTI patients (P < 0.0001 and P < 0.0001, respectively). On Cox multivariate analysis, CLTI was strongly predictive of all-cause mortality and amputation (hazard ratio [HR] 2.33 and HR 14.92, respectively). In patients with CLTI, chronic kidney disease was an independent predictor of mortality and amputation (HR 1.66 and HR 2.36, respectively). Smoking and ischemic heart disease were also independent predictors of mortality in this subgroup (HR 2.06 and HR 2.43, respectively). CONCLUSIONS: Although patients with IC and CLTI both manifest from atherosclerotic occlusive disease of the lower limb arteries, these patients may have different clinical outcomes with significant mortality occurred in both IC and CLTI groups. In patients with IC, the risk of amputation was less than 1% at 5 years following revascularization.

Risk factor analysis and treatment outcome of patients with spontaneous isolated celiac axis or superior mesenteric artery dissection.

BACKGROUND: Spontaneous isolated mesenteric artery (celiac axis or superior mesenteric artery [SMA]) dissection (IMAD) is a rare clinical entity. The aim of the present study was to examine the patient demographics, comorbidities, clinical and radiologic features, management, and prognosis and to identify the risk factors predictive of symptoms. METHODS: We performed a single-center, retrospective review from November 2005 to November 2021 of prospectively collected data from patients with a diagnosis of IMAD. The clinical data and radiologic images were reviewed, and statistical analysis was performed to compare the symptomatic and asymptomatic groups. RESULTS: A total of 78 patients were identified. Of the 78 patients, 24 (31%) had had celiac dissections, 51 (65%) had had SMA dissections, and 3 (4%) had had both celiac and SMA dissections. The mean age was 57.7 years (range, 36-84 years), with a male predominance (86%). More than one half (55%) of the patients had had hypertension. In addition, 29 patients (37%) were symptomatic, and 24 (31%) had been admitted to the hospital. The symptomatic patients with celiac axis dissections were more likely to have thrombosis (P = .02), significant stenosis (P = .01) or branch extension (P = .02). The symptomatic patients with SMA dissections were more likely to have a smaller artery diameter (P = .07), a longer dissection length (P = .05), thrombosis (P < .001), significant stenosis (P < .001), or branch extension (P = .003). The symptomatic patients were more likely to have been treated with antiplatelet or anticoagulant therapy (P < .001). Only three patients had undergone an intervention. Seven patients (9%) had died of unrelated causes. The Kaplan-Meier survival analysis showed a 5-year survival rate of 96% and 10-year survival rate of 91%. CONCLUSIONS: IMAD is an uncommon disease entity with a risk of visceral ischemia. Nonetheless, most of these patients can be treated conservatively with medication, with only a small minority requiring emergency surgery.

Modification of protocol with one extra drop of endovascular cyanoacrylate improved closure rates in incompetent great saphenous veins.

INTRODUCTION: Great saphenous vein diameter (GSV) of >8 mm was predictor of recanalization following Venaseal cyanoacrylate treatment. The aim of this study was to report our modified protocol with a single extra-drop for treatment for GSV>8 mm, and comparative duplex results in closure rates. METHODS: Patients in our single-centre registry treated with Venaseal were followed up by serial duplex examinations at week 1 and month(s)- 1, 6, 12, 18, 24, and then annually. The primary endpoint was successful obliteration of the GSV, secondary endpoints were closure distance from Saphenofemoral junction (SFJ), presence of endovenous glue-induced thrombosis (EGIT) or deep vein thrombosis. RESULTS: A total of 243 legs in 123 consecutive patients with duplex-proven SFJ/GSV incompetence were included in this study between September 2014 and October 2020. The median duplex follow-up period of this cohort of patients was 24 (range 0.2-58) months. Comparing closure rates in GSV diameter ≥8 mm treated with normal protocol, the 'extra-drop protocol' significantly improved closure rates (p = .034). However, the closure rates of ≥8 mm GSV treated with 'extra-drop protocol' was still not as good as GSV <8 mm (p < .001). There were no statistically significant differences in the stump distance between the three groups and no difference in the occurrence of EGIT. There were no deep vein thrombosis. CONCLUSION: Our experience showed that VenaSeal cyanoacrylate worked best in GSV<8 mm diameter. Even in GSV diameter of ≥8 mm which has a higher recanalization rate on follow-up duplex, our modified extra-drop protocol significantly improved the closure rates, and did not predispose to development of EGIT.

Lumivascular Optical Coherence Tomography-Guided Atherectomy in Recurrent Femoropopliteal Occlusive Diseases Associated with In-Stent Restenosis: Case-Series Report.

Lumivascular optical coherence tomography (OCT) is a novel adjunct in the field of medicine. It offers clear real-time imaging of artery walls before and during endovascular intervention. This study reports our initial experience on the use of lumivascular OCT-guided atherectomy in the management of two patients with recurrent restenosis in their femoropopliteal arteries associated with in-stent restenosis. Endovascular procedures were successful with a Pantheris atherectomy device (Avinger, Redwood City, CA, USA) and drug-eluting balloons. The OCT images clearly distinguished normal anatomy from plaque pathology, were of great advantage in both the accurate diagnosis and treatment of target lesions, and may reduce radiation during the endovascular procedure. However, the price of the device and its need for contrast infusion limit its routine clinical use.

A midterm analysis of patients who received femoropopliteal helical interwoven nitinol stents.

BACKGROUND: The aim of this study was to report midterm outcomes (up to 72 months) of patients who received femoropopliteal helical interwoven nitinol stents (Supera Peripheral Stent System, Abbott Laboratories, Inc, Webster, Tex). METHODS: Prospectively collected data on patients treated with femoropopliteal non-drug-eluting angioplasty and helical interwoven nitinol stents were retrospectively analyzed. Patients were followed up with 6, 12, 18, 24, 36, 48, 60, and 72 months clinical, duplex, and radiographic assessments. Restenosis is defined as 50% or greater restenosis of the target lesion on duplex ultrasound imaging. RESULTS: From October 2011 to September 2018, 315 patients (198 males) with 360 legs and a median age of 78 years (range, 46-100 years) were included. Symptoms of claudication, rest pain, and tissue loss were found in 212 (58.9%), 53 (14.7%), and 150 (41.7%) legs, respectively. In 176 (48.9%) legs, stents were placed in the popliteal segments. The mean stented lesion length was 119.0 mm (range, 40-450 mm). The overall primary patency rates at 6, 12, 24, 36, 48, 60, and 72 months were 90.6%, 80.5%, 73.8%, 68.9%, 65.3%, 63.1%, and 63.1%, respectively. The ankle-brachial pressure index increased from 0.58 ± 0.18 preoperatively to 0.87 ± 0.16 postoperatively. There were no stent fractures on follow-up. Patency rate was not statistically affected by indication of treatment, lesion calcification, or diabetes, but the length of stents and involvement of popliteal arteries were statistically significantly worse (log-rank test, P = .011 and P = .005). Stents with inner diameters of 4-mm had an initial lower patency compared with 5-mm stents, but the patency rates merged and crossed over at 46 months (log-rank test, P = .131). There was no procedural- or device-related morbidity or mortality, and there were nine major amputations after revascularization. CONCLUSIONS: This study provides long-term clinical data demonstrating that Supera stents are effective and durable.

Predictors of Recanalization for Incompetent Great Saphenous Veins Treated with Cyanoacrylate Glue.

PURPOSE: To determine predictors of recanalization in patients treated with endovenous cyanoacrylate. METHODS: Follow-up by serial clinical and duplex examinations was performed at 1 week, 1 month, 6 months, 12 months, and 24 months of 108 legs in 55 patients (21 men, median age 65 y) with primary varicose veins treated with endovenous cyanoacrylate. Cox regression analysis was used to examine venous characteristics before the procedure: diameter of great saphenous vein (GSV), treatment length of GSV, presence of incompetent perforators, clinical severity of varicose vein, and experience of operator as predictors of recanalization. With the patient in supine position, GSV diameter was measured at 3 levels (proximal thigh 1 cm from saphenofemoral junction, midthigh, and distal thigh above knee). RESULTS: Of 108 legs, 2 had minimal extension of thrombus to deep vein, and 4 had superficial thrombophlebitis. Kaplan-Meier analysis showed GSV closure rates were 97.2%, 92.3%, 89.2%, and 75.7% at 1 week, 1 month, 6 months, and 12 months after the procedure. With a median follow-up period of 5 months (range, 0-18 months), 4 legs had clinical recurrence. Mean GSV diameter ≥ 6.6 mm was the only significant predictor for recanalization (hazard ratio 12.1; 95% CI, 1.6-92.7; P = .016). CONCLUSIONS: The use of endovenous cyanoacrylate to treat varicose veins caused by incompetent GSV was safe. GSVs < 6.6 mm in diameter had a closure rate of 90.0% at 12 months. Despite 97.2% closure rates at 1 week, recanalization was observed in GSVs with larger diameter.

Cyanoacrylate glue used to treat great saphenous reflux: Measures of outcome.

Introduction This is a single-center clinical study for the evaluation of safety, efficacy, and performance of endovenous cyanoacrylate (Sapheon Venaseal Closure System, now Medtronic Medical) for the treatment of great saphenous vein (GSV) reflux. Methods Primary outcome measures included the GSV obliteration, with clinical recurrence on follow up as detected by serial clinical and duplex examinations of patients at 1 week, 1 month, 6 months, and 1 year. Venous clinical severity score (VCSS), Aberdeen varicose vein questionnaire (AVVQ), Short Form Health Survey 36 Item (SF-36) questionnaires were used at clinical follow up. Diameter of the GSV, treatment length of the GSV, and pretreatment clinical severity of the varicose vein were analyzed to predict recanalization using Cox regression analysis. Results Fifty-seven legs in 29 patients with primary varicose veins were included. One week follow-up duplex showed successful obliteration of the GSV in all except one of the legs. Two legs had minimal extension of thrombus to deep vein. None of the patients had deep venous thrombosis. All the patients were discharged the same day of operation. Median time to return to work was 1 day (range 1-16 days). Our VCSS, AVVQ, and the SF-36 physical and mental scores changed from a mean of 6.91, 23.66, 44.24, 54.26 at baseline to 2.43, 6.10, 43.85, 52.50 at 1 month post operation, respectively. Kaplan-Meier analysis showed that the GSV closure rates were 98.2%, 94.3%, 89.7%, and 78.5% at post-op 1 week, 1 month, 6 months, and 1 year, respectively. With median follow-up period of 9 months (range 1-13 months), no clinical recurrence of varicosity was observed. Mean GSV diameter ≥8 mm was a significant predictor for recanalization (hazard ratio 6.92, 95%CI 1.34-35.67, p = 0.021). Conclusion This study showed that the use of endovenous cyanoacrylate in the treatment of the GSV reflux was safe. All patients had symptomatic improvement as shown by the VCSS and AVVQ.

Outcome and risk factor analysis of patients who underwent open infrarenal aortic aneurysm repair.

INTRODUCTION: The aim of this study was to evaluate the short- and long-term outcomes in patients who underwent open infrarenal aortic aneurysm repair. METHODS: Consecutive patients who underwent open repair of infrarenal aortic aneurysms at our institution from July 1(st) 1990 to June 30(th) 2012 were reviewed from a prospective collected departmental database. Short-term outcomes included 30-day mortality and peri-operative complications. Independent risk factors to predict 30-day mortality were identified. Long-term survival and secondary interventions were also reported. RESULTS: Three hundred and eighty-three patients (317 males, median age 72 years with a range of 15-90 years) underwent open infrarenal aortic aneurysm repair during the period, of whom 266 (69.5%) were elective, 18 (4.7%) were urgent for symptomatic but nonruptured cases, and 99 (25.8%) were emergency procedures for ruptured aneurysms. Mean aneurysm size was 6.5 cm (ranging from 2.5 cm to15 cm). All patients were followed up for at least 24 months with a mean follow up period 163 months. Overall 30-day mortality was 11.0% (36.4% for ruptured cases, 11.1% for symptomatic cases, and 1.5% for elective cases; p < 0.001). Preexisting renal disease and ruptured aneurysms were independent risk factors for 30-day mortality (p = 0.001 and p = 0.006 respectively). Systemic complications included 50 cardiac events, 52 respiratory events, six renal events, three cerebral vascular accidents, and one deep vein thrombosis/pulmonary embolism. Local complications included two anastomotic/graft hemorrhage, 10 distal thrombosis/embolisms, five bowel ischemias, one spinal cord ischemia, and 17 wound complications. The ruptured group presented survival rates of 53.5%, 50.5%, 47.5%, 42.3%, 38.0%, 21.9%, and 12.5% at 1 year, 2 years, 3 years, 4 years, 5 years, 10 years, and 15 years, respectively; while nonruptured survival rates were 91.5%, 88.0%, 83.7%, 78.3%, 73.0%, 43.0%, and 25.3%, respectively (log rank p < 0.001). For those who died 30 days after the operation, only six patients (1.8%) died from aneurysm related mortality. A total of three (0.9%) patients underwent late re-interventions, one for late aorto-enteric fistulae and two for anastomotic pseudoaneurysms. CONCLUSION: In the current era of endovascular repair, open infrarenal aneurysm repair is effective and durable, and has very low secondary interventions rates.

Predictors of restenosis in the use of helical interwoven nitinol stents to treat femoropopliteal occlusive disease.

BACKGROUND: The femoropopliteal arteries are subjected to considerable axial and bending deformity due to flexion at the hip and knee joints. The Supera helical interwoven nitinol stent system (IDEV Technologies, Inc/Abbott Laboratories, Inc, Webster, Tex) has good conformability and flexibility, with a very low incidence of mechanical fatigue. This study reviewed our experience with the use of Supera stents for femoropopliteal atherosclerotic lesions and identified risk factors for restenosis or occlusion. METHODS: Patients with symptomatic femoropopliteal atherosclerotic diseases who underwent lower limb angioplasty and Supera stent insertion were studied. All patients had regular clinical follow-up and underwent a Doppler ultrasound examination at 3 months and then every 6 months, and radiography of the stents at 6, 12, 18, 24, 30, and 36 months. Patency rates were analyzed using Kaplan-Meier curves. We also evaluated the prospectively maintained cohort to identify predictors of restenosis. RESULTS: From October 2011 to December 2014, 164 legs in 153 symptomatic patients (96 male, 57 female) with femoropopliteal occlusive disease, with mean age of 76.7 years (range, 46-100 years), were included. Ninety-five patients (58%) had claudication, nine (5%) had rest pain, and 60 (37%) had tissue loss. Disease distribution was 64 proximal superficial femoral arteries (SFAs; 39%), 107 middle SFAs (65%), 127 distal SFAs (77%), 78 above-knee popliteal arteries (48%), and 19 below-knee popliteal arteries (12%). Lesion classification by TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) A, B, C, and D was 49 (30%), 79 (48%), 31 (19%), 3 (1%), respectively. The mean lesion length was 105.6 mm (range, 3-400 mm), and more than one Supera stent was inserted in 26 patients. Procedure success (residual stenosis <30%) was achieved in 100% of procedures. The primary patency rates (>50% patency) at 6, 12, 24, and 30 months were (±standard error) 86.7% ± 3.1%, 81.4% ± 3.7%, 79.9% ± 4.0%, and 77 ± 3.0%, respectively. The ankle-brachial pressure index increased from 0.57 ± 0.15 preoperatively to 0.87 ± 0.14 postoperatively. No stent fractures occurred. There were three 30-day deaths not related to the procedure or device, one major amputation 3 months after revascularization, and 29 late deaths (>30 days) of unrelated medical causes in follow-up. In-stent restenosis was associated with younger patient age and with dyslipidemia, long lesion, and stent length. CONCLUSIONS: Our midterm experience showed that the implantation of the helical interwoven nitinol stents in patients with femoropopliteal occlusive disease is safe and effective, with encouraging patency rates and clinical results.

Primary stenting of femoropopliteal atherosclerotic lesions using new helical interwoven nitinol stents.

BACKGROUND: The Supera helical interwoven nitinol stent has enhanced flexibility in counteracting fractures when placed in the femoropopliteal arteries and may improve patency. The aim of this study is to assess the early results of the Supera stent in symptomatic patients with femoropopliteal atherosclerotic lesions. METHODS: From October 2011 to April 2013, patients with symptomatic femoropopliteal lesions were treated with angioplasty and primary stenting using the Supera stent. They were followed up at 1, 3, 6, and 12 months with clinical, duplex, and radiographic assessments. Failure was defined as >50% restenosis of the target lesion on duplex ultrasound imaging or stent fracture on X rays. RESULTS: A total of 78 consecutive patients (46 males, 32 females) with 82 legs, mean age of 78.5 years (range, 57-97 years) were included. Symptoms of claudication, rest pain, and tissue loss were 48 (59%), 8 (10.1%), and 30 (37%), respectively. Ninety-six Supera stents were inserted in total. In 44 (53.7%) of the legs, stents were extended to the popliteal segments. The mean stented length was 12.6 cm (range, 4.0-38.0 cm). The primary patency rates at 6 and 12 months were 83.5% and 78.6%, respectively. The ankle brachial index increased from 0.58 ± 0.16 preoperative to 0.87 ± 0.14 postoperative. There were no stent fractures. Patency rate was not affected by severity of symptoms, stent lengths, femoro/popliteal stents (log-rank test, P = .50, .13, .52). All the patients reported symptomatic improvement. There was no procedural- or device-related morbidity or mortality, no major amputation after revascularization, and 10 patients died of unrelated cardiopulmonary/renal causes on follow-up. CONCLUSIONS: Our early experience shows that the Supera stents are effective in our cohort of elderly patients, with acceptable patency rates. There were no stent fractures so far even with stenting of the popliteal segments.

Multicenter audit of emergency endovascular repair of infrarenal aortic aneurysms.

BACKGROUND: Emergency endovascular aneurysm repair (eEVAR) for infrarenal abdominal aortic aneurysm has become widely accepted as an alternative to open repair, if the aortic anatomy is favorable and endovascular expertise is readily available. The aim of this study is to report the outcome of eEVAR in Hong Kong. METHODS: This was a retrospective review of prospectively collected data from Hong Kong Hospital Authority Clinical Data Analysis and Reporting System (CDARS), Clinical Management System (CMS), and departmental prospective computerized databases. Patient demographics, clinical and biochemical parameters, perioperative complications, and outcomes were recorded and analyzed. The independent sample t-test was used for continuous variables and the Fisher's exact test was used for nonparametric variables. Kaplan-Meier analysis was performed for overall survival and survival of subgroups. Binary logistic regression was performed for factors predicting perioperative mortality. SPSS software (version 15.0; SPSS Inc., Chicago, IL) was used for all statistical analyses. RESULTS: A total of 40 patients (36 men with a mean age of 74.9 ± 1.53 years [range: 52-89 years]) underwent emergency eEVAR between January 2006 and September 2011 in 6 Hospital Authority Hospitals in Hong Kong. All patients were treated using commercially available aortoiliac endografts (including 26 bifurcated and 14 aorto-uniiliac grafts). There was 1 conversion from eEVAR to open repair. Blood loss, operating time, duration of stay in intensive care, and duration of stay in the hospital were 948 ± 495.5 mL, 194 ± 12.7 min, 4.7 ± 1.26 days, and 14.5 ± 2.19 days, respectively. The 7-day, 30-day, and 12-month mortality rates were 15%, 17.5%, and 35%, respectively. Six patients required reintervention on follow-up, and 8 patients died during hospitalization. Cox regression analysis of survival found that hypotension (P = 0.001) and being >76 years of age (P = 0.002) were associated with reduced overall survival. Binary logistic regression found that hypotension is associated with increased 30-day mortality (P = 0.026). CONCLUSIONS: This audit shows that the results of eEVAR in Hong Kong are comparable to international standards. In the endovascular era, this may be an attractive alternative to emergency open aneurysm repair.

Endovascular repair for thoracic aortic pathologies--early and midterm results.

OBJECTIVE: To assess the early and midterm results of endovascular stent graft repair in patients with thoracic aortic pathologies. METHODS: Between March 2000 and December 2005, 44 consecutive patients undergoing endovascular repair for 45 thoracic aortic lesions were studied. Follow-up protocol includes regular clinical examination and computed tomographies. RESULTS: There were 37 men and 7 women with a median age of 59 years at operation (range, 26-90). The pathologies consisted of 15 thoracic aortic aneurysms, nine pseudoaneurysms, 16 thoracic aortic dissections, and five thoracic aortic injuries. Successful deployment of the endovascular stent grafts with complete sealing of the pathology were achieved in all but one patient who had the procedure abandoned as a result of access difficulty, giving a technical success of 98%. The median hospital stay was 7 days (range, 3-196), with no hospital death nor paraplegia. The median follow-up was 25 months (range, 0-86). There were eight follow-up deaths, two of which were thoracic aortic pathology related (both patients had aortoesophageal fistulae). There were three other clinical failures: distal attachment endoleak in a patient with thoracic aortic aneurysm, one enlarging and one newly developed dissecting thoracic aortic aneurysm despite endografting. The cumulative freedom from clinical failure and failure free survival were 90% and 75% at 18 months respectively. CONCLUSION: Endovascular stent graft repair is a feasible option in thoracic aortic pathologies with promising early and midterm results.

Endovascular repair for abdominal aortic aneurysms: the first hundred cases.

OBJECTIVE: To evaluate the early and mid-term results of the first 100 elective endovascular repairs for abdominal aortic aneurysms. DESIGN: Retrospective analysis of prospectively collected data. SETTING: University teaching hospital, Hong Kong. PATIENTS: The first 100 patients with infrarenal abdominal aortic aneurysms who underwent elective endovascular repair. MAIN OUTCOME MEASURES: Peri-operative data, mortality and morbidities as well as the follow-up details were recorded. Cumulative data on endoleaks, clinical failures, secondary procedures, and survival were evaluated with Kaplan-Meier analyses. RESULTS: There were 85 men and 15 women, with a mean age of 75 (range, 50-90) years. Failed implantations due to access difficulty occurred in two patients during the same period, giving a technical success rate of 98%. The mean aneurysm diameter was 6.2 cm. Access site injury requiring repair occurred in four (4%) of the patients, while wound problems were the most common complications (11%). The median hospital stay was 6 days, and there were two hospital deaths, giving a hospital mortality rate of 2%. During a mean follow-up of 36 (standard deviation, 24) months, there were three aneurysmal ruptures and four elective open conversions, with only one aneurysm-related death after hospital discharge. At 3 years, the cumulative rates of freedom from any endoleak, freedom from primary failure, freedom from secondary failure, freedom from secondary procedures, and survival were 60%, 84%, 89%, 88%, and 78%, respectively. CONCLUSIONS: The early and mid-term results of elective endovascular repair for abdominal aortic aneurysms appear promising. The procedure is effective in preventing aneurysm-related death in the mid-term. Nevertheless, the importance of constant surveillance cannot be over-emphasised, as clinical failures and ruptures are still a concern.

Identification and functional characterization of three novel human melanocortin-4 receptor gene variants in an obese Chinese population.

OBJECTIVE: Mutations in the melanocortin-4 receptor gene (MC4R) are the most common monogenic form of human obesity. However, the contribution of MC4R mutations to obesity in Chinese has not been investigated. We studied the frequency of MC4R mutations in an obese southern Chinese population and the functional consequences of the novel variants identified. METHODS: We screened for MC4R mutations in 227 obese [body mass index (BMI) 35.29 +/- 5.75 kg/m2] and 100 lean (BMI 21.57 +/- 0.29 kg/m2) southern Chinese subjects using PCR-direct sequencing. In vitro functional studies, including cell surface expression, ligand binding, and cyclic adenosine monophosphate (cAMP) accumulation, were performed to examine the functional properties of three novel missense mutations. RESULTS: Apart from two previously reported polymorphisms, V103I and -176 A > C, three novel missense heterozygous variants (Y35C, C40R and M218T) were identified. The polymorphisms -176 A > C and Y35C were detected in both obese and normal subjects with similar frequency. C40R was identified only in an obese subject. Pedigree analysis revealed M218T carriers in both lean and obese subjects. The prevalence of V103I carriers in normal-weight controls was significantly higher than that in obese subjects (5.3%vs. 1.3%, P < 0.05). In vitro functional studies showed that all three novel missense variants have normal functions. CONCLUSIONS: Two known polymorphisms and three novel variants of the MC4R were identified. No overt functional defects were observed for the three novel MC4R variants, suggesting that they might not be the cause of obesity in variant carriers.

Reduction in deep vein reflux after concomitant subfascial endoscopic perforating vein surgery and superficial vein ablation in advanced primary chronic venous insufficiency.

BACKGROUND: Subfascial endoscopic perforating vein surgery (SEPS) and superficial vein surgery (SVS) have been the recommended treatment for advanced chronic venous insufficiency (CVI), despite a high prevalence of deep vein reflux in these patients. The anatomic and hemodynamic results of these procedures, however, remain uncertain. It is hypothesized that concomitant SEPS and SVS would result in a reduction of deep vein reflux in patients with advanced primary CVI. We investigated the effect of concomitant SEPS and SVS on deep vein reflux as well as the associated hemodynamic and clinical changes after surgery in a cohort of patients with advanced primary CVI. METHODS: We prospectively evaluated 53 consecutive SEPSs with concomitant SVS procedures in 47 patients with advanced primary CVI. There were 25 men and 22 women with a mean age of 58 years at operation. Thirty-four procedures (64%) were performed for limbs with active venous ulcers (class 6), and the other 19 procedures were performed for 15 class 5 limbs, one class 4a limb, and three class 4b limbs, respectively. Duplex scan and air plethysmography were performed before operation, at 1 month, and at 1 year after operation. The patients were followed up regularly with clinical assessment, and the ulcer healing and recurrence rates were documented. RESULTS: The proportion of limbs with common femoral vein incompetence decreased from 68% to 28% at 1 month and to 32% at 1 year after operation. The proportion of limbs with deep vein incompetence at more than one site also decreased from 42% to 15% at 1 month and to 12% at 1 year after concomitant SEPS and SVS. Venous hemodynamics as measured by air plethysmography improved significantly after operation. The cumulative ulcer healing was 85% at 3 months and 97% at 6 months. With a mean follow-up of 31 +/- 16 months, all ulcers healed. Only three recurrent ulcers (6%) were detected during the follow-up period. CONCLUSION: Concomitant SEPS and SVS are effective in reducing deep vein reflux and results in hemodynamic and clinical improvements in patients with advanced primary CVI. Deep vein reconstruction procedures may not be necessary in these patients.

Plasma fibrinogen level: an independent risk factor for long-term survival in Chinese patients with peripheral artery disease?

Fibrinogen, an inflammatory marker as well as a fundamental part of the coagulation cascade, is suggested to play a significant role in the pathogenesis of atherosclerosis and complications of atherothrombotic diseases. The aim of this study was to determine if plasma fibrinogen is an independent risk factor for long-term survival in patients with peripheral artery disease (PAD). Altogether, 139 Chinese patients (88 men, 51 women) with PAD were consecutively recruited for the study. Atherothrombotic risk factors and fibrinogen levels were determined at presentation, and all patients were followed up for mortality prospectively. The mean follow-up was 6 years. All variables were first correlated with survival rates using Kaplan-Meier analysis and compared by means of the log-rank test. Significant risk factors were identified, and multivariate Cox regression analysis was used to evaluate the independent contribution of the fibrinogen level to the risk of mortality. During follow-up, 95 patients (68.3%) died. The overall survival rate was 77.7% at 3 years, 56.8% at 5 years, and 31.2% at 10 years (standard errors 0.05, 0.06, and 0.07, respectively). All-cause mortality rate increased with an elevated fibrinogen level. Eighty percent of patients with a fibrinogen level > 3.4 g/L had a survival time of less than 3 years (p = 0.002). This relation was also demonstrated within patients with critical ischemia. The plasma fibrinogen level was thus identified as an independent risk factor for mortality in PAD patients after adjusting for confounding factors.

Perioperative deep vein thrombosis in Chinese patients undergoing craniotomy.

BACKGROUND: We attempted to determine the incidence of perioperative deep vein thrombosis (DVT) in Chinese patients undergoing elective craniotomy for brain tumors and to assess the efficacy of clinical and serial calf circumference assessment in detecting DVT. METHODS: Between June 1999 and February 2001, 100 consecutive patients who underwent elective craniotomy for brain tumors at the Department of Neurosurgery, University of Hong Kong Medical Centre were examined for perioperative DVT. The demographic data, Glasgow coma score (GCS), mobility status, and the operative details were recorded. Graduated compression stockings and intermittent pneumatic compression were applied perioperatively as prophylaxis against DVT. Serial duplex scans were performed before and after operation. Clinical examination was also performed daily to look for signs of DVT. The calf circumference was measured at fixed levels for both limbs before each duplex scan surveillance. RESULTS: The study group consisted of 44 males and 56 females, with a mean age of 54 +/- 15 years (range, 20-81 years). There was no preoperative DVT. Postoperative DVT was detected on duplex scan in four patients (4%), two of whom had bilateral involvement. The thrombosis was confined to the calf veins in two limbs. The demographic data, neurologic status and operative details of patients with and without DVT were similar. Patients with DVT had no clinically recognizable signs. The change in calf circumference measurement was also not predictive of DVT. CONCLUSIONS: The incidence of perioperative DVT in Chinese patients undergoing elective craniotomy for brain tumors appears to be low with the present mechanical prophylactic measures. Given the low incidence of proximal DVT as detected by duplex scan, the use of heparin prophylaxis may not be justified because of the increased risk of intracranial bleeding. Clinical assessment with calf circumference measurement is unreliable in the diagnosis of DVT.

Early and late outcomes in Hong Kong Chinese patients undergoing carotid endarterectomy.

OBJECTIVE: To determine the benefit of carotid endarterectomy (CEA) for stroke prevention by reviewing the early and late outcomes of Hong Kong Chinese patients undergoing CEA who have a high reported incidence of intracranial atherosclerotic disease (IAD). METHODS: Fifty-nine Chinese patients underwent 62 CEA. There were 48 males and 11 females, with a mean age of 70 +/- 7 years (range: 52 - 86 years). Twenty-one CEA (34%) were performed for asymptomatic disease. Duplex scan was the primary tool of evaluation prior to surgery. Preoperative angiography was done in 36 instances (58%). All CEA were performed under general anaesthesia with routine intraoperative shunting. The arteriotomy was closed primarily in all patients except three. Patients were followed up regularly with six-monthly Duplex scan surveillance. RESULTS: There were 2 perioperative neurological events consisting of one transient ischemic attack and one minor stroke. There was no operative mortality or major morbidity such as bleeding or cranial nerve injury. Mean hospital stay was 6.5 +/- 4 days (range: 3 - 26 days). The patients were followed up for a mean interval of 24 +/- 17 months (range: 1 - 57 months). Seven patients died during follow-up and subsequent neurological events occurred in 5 patients, including 2 fatal strokes. The 3-year survival, freedom from stroke and stroke free survival were 86%, 87% and 83%, respectively. One recurrent stenosis of 80% was detected on follow-up Duplex scan. CONCLUSIONS: Despite a high incidence of IAD, CEA in Hong Kong Chinese patients is associated with acceptable perioperative morbidity and mortality with satisfactory long-term efficacy in stroke prevention.