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Randomized Clinical Trial of the Use of Glyceryl Trinitrate Patches to Aid Arteriovenous Fistula Maturation
1890
Abstracts
Journal of Vascular Surgery December 2016
Impact of the First 5 Years of a National Abdominal Aortic Aneurysm Screening Programme Jacomelli J, Summers L, Stevenson A, et al. BJS 2016;103:1125-31. Conclusions: In the UK National Health Service (NHS) abdominal aortic aneurysm (AAA) screening programs are effective in detecting AAA and lead to effectively treating men with AAA. Summary: Approximately 3000 to 4000 people die from ruptured AAA each year in England and Wales. Most of the deaths occur in men over 65 years of age. Population screening of men $65 years of age for AAA in the UK began in 2009 and was implemented in all of England by April 2013. The current study presented here reviews the results of the first 5 years of screening among 65 year old men who had attended an ultrasound screening and the first cohort of men referred for treatment of a large aneurysm over 5.47 cm. The goal was to check the systems and processes of the AAA screening program. In the program men aged 65 years were invited for a single abdominal ultrasound scan. Data were entered into a bespoke database (AAA SMaRT). This paper represents a planned analysis after the first 5 years of the program. Summation analysis involves the first 700,000 men screened and the first 1000 men with a large AAA referred for possible treatment. The prevalence of AAA defined as an aortic diameter larger than 2.9 cm in 65 year old men was 1.34%. The mean uptake was 78.1% and varied from 61.7 to 85.8% across the UK. Based on the index of multiple deprivation, uptake was 65.1% in the most deprived vs 84.1% in the least deprived areas. Of the first 1000 men referred for possible treatment of an AAA the false positive rate was 3.2%. 770 men underwent a planned AAA intervention (non-intervention rate 9.2%) with 7 deaths for a perioperative mortality rate of 0.8%. Comment: Use of the screening program varied among regions in the UK with those from less affluent areas and having to travel greater distances making less use of the screening program (Crilly M, et al Br J Surg 2015;102:916-23). Perhaps patients who place a less priority on their own health have an increased prevalence of AAA so the prevalence of AAA may be higher than indicated. False negative rates of screening are unknown. Nevertheless, at the moment it appears from this analysis, screening for AAA is effective both from a medical and cost effectiveness point of view.
Quality of Life From a Randomized Trial of Open and Endovascular Repair for Abdominal Aortic Aneurysm De Bruin JL, Groenwold RHH, Baas AF, et al. BJS 2016;103:995-1002. Conclusions: Long-term health-related quality of life (HRQoL) may be better following open rather than endovascular abdominal aortic aneurysm (AAA) repair. Summary: EVAR has been associated with a quality of life advantage immediately following AAA repair. Other studies, however, have showed no significant differences in short-term benefits after EVAR and in some studies benefit is not sustained after 3 months and offset by worse midterm quality of life scores (Prinssen M et al, Eur J Vasc Endovasc Surg 2004;27:121-7). In contrast, recent systematic reviews have suggested a significant deterioration in quality of life following aneurysm repair which may be more pronounced following open repair compared with EVAR at 3 and 12 months (Coughlin PA et al, Br J Surg 2013;100:448-55, and Kayssi A et al, J Vasc Surg 2015;62:491-8). The aim of this study was to evaluate long-term HRQoL and health status after EVAR and open AAA surgery in patients enrolled in the multicenter randomized clinical trial (DREAM trial; 2000-2003) of open vs endovascular repair of AAA. In DREAM patients were asked to complete questionnaires on health status and HRQoL. HRQoL scores were assessed at baseline and at 13 time points thereafter using generic tools, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and EuroQol 5D (EQ-5D). Physical component summary (PCS) and mental component summary (MCS) scores were calculated. Follow-up was 5 years. There were 332 of 351 patients enrolled in the trial who returned questionnaires. More than 70% of questionnaires were returned at each time point. Both surgical interventions had a short term negative effect on HRQoL and SF-36. This was less severe in the EVAR group than in the open repair group. In the long-term, the physical domains of SF-36 favored open repair. The mean difference in PCS score between open repair and EVAR was
1.98 (95% confidence interval [CI], 3.56 to 0.41). EQ-5D descriptive and EQ-5D visual analog scale scores for open repair were also superior to those for EVAR after the initial 6-week interval; mean differences (0.06 [95% CI, 0.10 to 0.02] and 4.09 [95% CI, 6.91 to 1.27], respectively). Comment: In this study there appears to be a significant long-term difference between open and EVAR in regard to HRQoL that favors open repair in several domains of SF-36 and EQ-5D. These results are inconsistent with those from the OVER trial (Lederle FA et al, N Engl J Med 2012;367:1988-97). This may reflect a shorter length of follow-up and fewer reinterventions and cardiovascular events in OVER. Patient reported outcomes are becoming increasingly important in clinical medicine. However, it seems likely most patients will favor the short-term perioperative mortality and morbidity benefits of EVAR in considering their choice of an open or endovascular AAA repair so the impact of this study with regard to patient choice of EVAR vs open repair is likely to be minimal.
Randomized Clinical Trial of the Use of Glyceryl Trinitrate Patches to Aid Arteriovenous Fistula Maturation Field M, McGrogan D, Marie Y, et al. BJS 2016;103:1269-75. Conclusions: Glycerol trinitrate (GTN) in external patches used for 24 hours after surgery does not improve arteriovenous fistula maturation. Summary: There are many nonmodifiable factors such as diabetes, age, hypotension, atherosclerosis and arteriovenous diameter that affect arteriovenous fistula (AVF) maturation. In a recent meta-analysis the only modifiable factors affecting fistula maturation were timely referral for AVF creation and routine use of pre-operative ultrasound imaging (Smith G et al, J Vasc Surg 2012;55:849-55). In addition, pharmacologic and interventional therapies have been less than impressive in promoting fistula maturation with no significant effects observed (Tanner NC et al, Cochrane Database Systematic Rev 2015;(7)CD002786). Glyceryl trinitrate (GTN) is a nitrate based vasodilator that also seems to aid in decreasing platelet aggregation. In experimental studies where it is locally applied GTN has shown potential at improving fistula maturation (Akin EB et al, World J Surg 2002;26:1256-9). Locally applied GTN transdermal patches increase fistula blood flow for 24 hours. It has been suggested this application might improve maturation. The purpose of this randomized clinical trial was to determine whether use of GTN patches aids arteriovenous fistula maturation. Patients who were referred for arteriovenous fistula formation were eligible. GTN and placebo patches were applied immediately after surgery and left in situ for 24 hours. The primary outcome measure was the change of venous diameter at 6 weeks after fistula formation. The secondary outcome measure was clinical fistula patency at 6 weeks. 533 patients were screened for this study and 200 recruited. 101 were randomized to the placebo group and 99 to the GTN group. Of these, 81 and 86 respectively completed surgery and had follow up data available at 6 weeks. Improvements in venous diameter were similar in the two groups: mean (SD) increase 2.3 (1.9) mm in the placebo group compared with 2.2 (1.8) mm in the GTN group (P ¼ .704). Fistula failure rate did not significantly differ between the 2 groups. There was 23% failure for placebo group and 28% failure for GTN (P ¼ .596). Comment: In the study, transdermal GTN had no significant effect on arteriovenous fistula maturation. The result is consistent with previous well designed studies assessing a variety of medical adjunctive therapies to try and improve fistula maturation following vascular access surgery. Although previous small, non-randomized studies have supported the use of GTN, the current larger and randomized controlled study provides no evidence to support the use of topical GTN following primary AVF creation. Once again, a properly conducted randomized clinical trial has provided different outcomes than prior case series and nonrandomized studies. RCTs remain the gold standard for testing clinical interventions.
Meta-Analysis of the Current Prevalence of Screen-Detected Abdominal Aortic Aneurysm in Women Ulug P, Powell JT, Sweeting MJ, and the SWAN Collaborative Group. BJS 2016;103:1097-104. Conclusions: Current population prevalence of screen-detected abdominal aortic aneurysm (AAA) in older women is subject to wide
Abstracts
Journal of Vascular Surgery December 2016
Impact of the First 5 Years of a National Abdominal Aortic Aneurysm Screening Programme Jacomelli J, Summers L, Stevenson A, et al. BJS 2016;103:1125-31. Conclusions: In the UK National Health Service (NHS) abdominal aortic aneurysm (AAA) screening programs are effective in detecting AAA and lead to effectively treating men with AAA. Summary: Approximately 3000 to 4000 people die from ruptured AAA each year in England and Wales. Most of the deaths occur in men over 65 years of age. Population screening of men $65 years of age for AAA in the UK began in 2009 and was implemented in all of England by April 2013. The current study presented here reviews the results of the first 5 years of screening among 65 year old men who had attended an ultrasound screening and the first cohort of men referred for treatment of a large aneurysm over 5.47 cm. The goal was to check the systems and processes of the AAA screening program. In the program men aged 65 years were invited for a single abdominal ultrasound scan. Data were entered into a bespoke database (AAA SMaRT). This paper represents a planned analysis after the first 5 years of the program. Summation analysis involves the first 700,000 men screened and the first 1000 men with a large AAA referred for possible treatment. The prevalence of AAA defined as an aortic diameter larger than 2.9 cm in 65 year old men was 1.34%. The mean uptake was 78.1% and varied from 61.7 to 85.8% across the UK. Based on the index of multiple deprivation, uptake was 65.1% in the most deprived vs 84.1% in the least deprived areas. Of the first 1000 men referred for possible treatment of an AAA the false positive rate was 3.2%. 770 men underwent a planned AAA intervention (non-intervention rate 9.2%) with 7 deaths for a perioperative mortality rate of 0.8%. Comment: Use of the screening program varied among regions in the UK with those from less affluent areas and having to travel greater distances making less use of the screening program (Crilly M, et al Br J Surg 2015;102:916-23). Perhaps patients who place a less priority on their own health have an increased prevalence of AAA so the prevalence of AAA may be higher than indicated. False negative rates of screening are unknown. Nevertheless, at the moment it appears from this analysis, screening for AAA is effective both from a medical and cost effectiveness point of view.
Quality of Life From a Randomized Trial of Open and Endovascular Repair for Abdominal Aortic Aneurysm De Bruin JL, Groenwold RHH, Baas AF, et al. BJS 2016;103:995-1002. Conclusions: Long-term health-related quality of life (HRQoL) may be better following open rather than endovascular abdominal aortic aneurysm (AAA) repair. Summary: EVAR has been associated with a quality of life advantage immediately following AAA repair. Other studies, however, have showed no significant differences in short-term benefits after EVAR and in some studies benefit is not sustained after 3 months and offset by worse midterm quality of life scores (Prinssen M et al, Eur J Vasc Endovasc Surg 2004;27:121-7). In contrast, recent systematic reviews have suggested a significant deterioration in quality of life following aneurysm repair which may be more pronounced following open repair compared with EVAR at 3 and 12 months (Coughlin PA et al, Br J Surg 2013;100:448-55, and Kayssi A et al, J Vasc Surg 2015;62:491-8). The aim of this study was to evaluate long-term HRQoL and health status after EVAR and open AAA surgery in patients enrolled in the multicenter randomized clinical trial (DREAM trial; 2000-2003) of open vs endovascular repair of AAA. In DREAM patients were asked to complete questionnaires on health status and HRQoL. HRQoL scores were assessed at baseline and at 13 time points thereafter using generic tools, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and EuroQol 5D (EQ-5D). Physical component summary (PCS) and mental component summary (MCS) scores were calculated. Follow-up was 5 years. There were 332 of 351 patients enrolled in the trial who returned questionnaires. More than 70% of questionnaires were returned at each time point. Both surgical interventions had a short term negative effect on HRQoL and SF-36. This was less severe in the EVAR group than in the open repair group. In the long-term, the physical domains of SF-36 favored open repair. The mean difference in PCS score between open repair and EVAR was
1.98 (95% confidence interval [CI], 3.56 to 0.41). EQ-5D descriptive and EQ-5D visual analog scale scores for open repair were also superior to those for EVAR after the initial 6-week interval; mean differences (0.06 [95% CI, 0.10 to 0.02] and 4.09 [95% CI, 6.91 to 1.27], respectively). Comment: In this study there appears to be a significant long-term difference between open and EVAR in regard to HRQoL that favors open repair in several domains of SF-36 and EQ-5D. These results are inconsistent with those from the OVER trial (Lederle FA et al, N Engl J Med 2012;367:1988-97). This may reflect a shorter length of follow-up and fewer reinterventions and cardiovascular events in OVER. Patient reported outcomes are becoming increasingly important in clinical medicine. However, it seems likely most patients will favor the short-term perioperative mortality and morbidity benefits of EVAR in considering their choice of an open or endovascular AAA repair so the impact of this study with regard to patient choice of EVAR vs open repair is likely to be minimal.
Randomized Clinical Trial of the Use of Glyceryl Trinitrate Patches to Aid Arteriovenous Fistula Maturation Field M, McGrogan D, Marie Y, et al. BJS 2016;103:1269-75. Conclusions: Glycerol trinitrate (GTN) in external patches used for 24 hours after surgery does not improve arteriovenous fistula maturation. Summary: There are many nonmodifiable factors such as diabetes, age, hypotension, atherosclerosis and arteriovenous diameter that affect arteriovenous fistula (AVF) maturation. In a recent meta-analysis the only modifiable factors affecting fistula maturation were timely referral for AVF creation and routine use of pre-operative ultrasound imaging (Smith G et al, J Vasc Surg 2012;55:849-55). In addition, pharmacologic and interventional therapies have been less than impressive in promoting fistula maturation with no significant effects observed (Tanner NC et al, Cochrane Database Systematic Rev 2015;(7)CD002786). Glyceryl trinitrate (GTN) is a nitrate based vasodilator that also seems to aid in decreasing platelet aggregation. In experimental studies where it is locally applied GTN has shown potential at improving fistula maturation (Akin EB et al, World J Surg 2002;26:1256-9). Locally applied GTN transdermal patches increase fistula blood flow for 24 hours. It has been suggested this application might improve maturation. The purpose of this randomized clinical trial was to determine whether use of GTN patches aids arteriovenous fistula maturation. Patients who were referred for arteriovenous fistula formation were eligible. GTN and placebo patches were applied immediately after surgery and left in situ for 24 hours. The primary outcome measure was the change of venous diameter at 6 weeks after fistula formation. The secondary outcome measure was clinical fistula patency at 6 weeks. 533 patients were screened for this study and 200 recruited. 101 were randomized to the placebo group and 99 to the GTN group. Of these, 81 and 86 respectively completed surgery and had follow up data available at 6 weeks. Improvements in venous diameter were similar in the two groups: mean (SD) increase 2.3 (1.9) mm in the placebo group compared with 2.2 (1.8) mm in the GTN group (P ¼ .704). Fistula failure rate did not significantly differ between the 2 groups. There was 23% failure for placebo group and 28% failure for GTN (P ¼ .596). Comment: In the study, transdermal GTN had no significant effect on arteriovenous fistula maturation. The result is consistent with previous well designed studies assessing a variety of medical adjunctive therapies to try and improve fistula maturation following vascular access surgery. Although previous small, non-randomized studies have supported the use of GTN, the current larger and randomized controlled study provides no evidence to support the use of topical GTN following primary AVF creation. Once again, a properly conducted randomized clinical trial has provided different outcomes than prior case series and nonrandomized studies. RCTs remain the gold standard for testing clinical interventions.
Meta-Analysis of the Current Prevalence of Screen-Detected Abdominal Aortic Aneurysm in Women Ulug P, Powell JT, Sweeting MJ, and the SWAN Collaborative Group. BJS 2016;103:1097-104. Conclusions: Current population prevalence of screen-detected abdominal aortic aneurysm (AAA) in older women is subject to wide