First Experience of a Novel Femorocrural Expanded Polytetrafluoroethylene Bypass Graft Steven J. Tuijp, Hans C. Flu, Jeroen M.W. Donker, Eelco J. Veen, Gwan H. Ho, Hans G. de Groot, Jan C. van der Waal, and Lyckle van der Laan, Breda, The Netherlands
Background: This study aims to evaluate early results of a precuffed expanded polytetrafluoroethylene (ePTFE) DistafloÒ Mini-Cuff Bypass Graft versus autologous saphenous vein (ASV) grafting in patients with peripheral arterial obstructive disease (PAOD). Methods: This retrospective single-center study analyzed 42 patients who received a femorocrural bypass graft because of PAOD using an ASV graft (n ¼ 28) or Distaflo Mini-Cuff graft (n ¼ 14). Results: Primary patency rates in the ASV and Distaflo Mini-Cuff groups were 81% and 69%, respectively, after 6 months. Secondary patency rates were 81% and 35%, respectively, after 12 months. The limb salvage rate was 81% in the ASV group vs 65% and 35%, respectively, in the Distaflo Mini-Cuff group after 6 months and 1 year. Conclusions: The ePTFE Distaflo Mini-Cuff is an option for revascularization in the absence of a suitable ASV. However, the performance of this novel graft is not better than that of current ePTFE bypass grafts.
INTRODUCTION Peripheral arterial occlusive disease (PAOD) is a major public health problem and also very common in the western world. The prevalence of symptomatic PAOD seems to increase from approximately 3% in individuals aged 40 years to 6% in patients aged 60 years.1 Approximately 1e3% of all patients with PAOD are diagnosed with critical limb ischemia (CLI).2,3 The primary goals of CLI treatment are to relieve ischemic pain, heal ischemic ulcers, prevent limb loss, improve patient function and quality of life, and prolong patient survival. In the case of revascularization, the first choice is endovascular Department of Surgery, Amphia Hospital, Breda, The Netherlands. Correspondence to: Department of Surgery, Amphia Hospital, Molengracht 21, 4818 CK Breda 5953818, The Netherlands; E-mail: [email protected] Ann Vasc Surg 2014; 28: 620–627 http://dx.doi.org/10.1016/j.avsg.2013.04.024 Ó 2014 Elsevier Inc. All rights reserved. Manuscript received: January 8, 2013; manuscript accepted: April 22, 2013; published online: December 17, 2013.
620
treatment if possible. In the case of surgical revascularization, the autologous saphenous vein (ASV) is still the preferred conduit and provides the best patency and limb salvage rates in femorocrural bypass graft procedures. However, in the absence of a suitable ASV, the use of a small-diameter prosthesis (6 mm) is widely implemented in lower extremity arterial revascularization with a crural distal anastomosis.4,5 A novel precuffed expanded polytetrafluoroethylene (ePTFE) DistafloÒ Mini-Cuff Bypass Graft (Bard Peripheral Vascular Inc., Tempe, AZ, USA),6 with an additional internal diameter reduction of 1 mm over the distal 25 cm of the graft compared with the standard and small cuff precuffed ePTFE Distaflo graft, has been developed for crural bypass surgery. The rationale for this new graft is a smaller distal cuff, which allows a smaller distal anastomosis. Currently, no literature has reported the results of the Distaflo Mini-Cuff graft. This study compared the primary patency, secondary patency, and limb salvage rates of the Distaflo Mini-Cuff graft and ASV bypass grafts in patients
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Novel femorocrural ePTFE 621
with critical limb ischemia after femorocrural bypass surgery in the 6- and 12-month postoperative periods.
Table I. Patient characteristics and comorbidities before revascularization
MATERIALS AND METHODS
Characteristics
Patients
Gender Male Female Age (y) Mean (min; max) BMI Overweight Obesity ASA classification 2 3 4 Comorbidity Arterial hypertension Diabetes History of smoking Cardiac disease Pulmonary disease Renal disease Carotid disease
ePTFE Distaflo Total Mini-cuff ASV (n ¼ 42) (n ¼ 14) (n ¼ 28) P value
0.18a 25 17
6 8
19 9
Criteria for inclusion were CLI; ischemic rest pain with a resting ankle pressure (AP) less than 40 mm Hg; and gangrene or nonhealing ischemic ulceration with a resting AP less than 60 mm Hg, corresponding with Rutherford categories 4, 5, and 6 of the Society of Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery (SVS/ISCVS) standards, and according to the Trans-Atlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease (TASC)1,7 guidelines. Bypass surgery was performed according to standard vascular techniques. All surgeries were performed by or under the supervision of a vascular surgeon. As listed in Table I, 2 groups of patients were considered according to type of bypass graft: those who were revascularized with a Distaflo Mini-Cuff graft and those who had an ASV bypass graft. Patients who had a missing ipsilateral ASV were revascularized using the contralateral saphenous vein or the lesser saphenous vein if possible. The brachial veins, however, were not considered for use as a bypass graft. The enrolled patients underwent a bypass graft between September 2009 and December 2011. All patients received oral antiplatelet agents and lipidlowering agents to achieve the secondary pharmacologic prevention.
exploration if the ultrasound assessment was inconclusive.
Surgical Workup
Postoperative Care
Before revascularization, the vascular assessment included an ankle-brachial pressure index (ABI), a treadmill test, a venous and arterial Duplex ultrasound assessment, and either a digital subtraction angiography or a magnetic resonance angiography scan. The femorocrural bypass graft procedure was performed according to standard vascular techniques recommended by the SVS/ISCVS and TASC guidelines, preferably using an autologous vein.1,7 Patients were considered for a Distaflo Mini-Cuff graft if both the ipsilateral and contralateral ASVs or the lesser saphenous veins were absent or unsuitable to be used as an autologous bypass graft. Judgment was based on a perioperative ultrasound evaluation or the findings of open surgical
The definition of primary and secondary patency, the decision to intervene, and the type of (re)-intervention were based on the SVS/ISCVS and TASC reporting standards. Primary patency was defined as blood flow through vessels without any previous revascularization procedure for an occlusion or stenosis. Secondary patency was defined as blood flow through a vessel that required reintervention (i.e., embolectomy or thrombolysis). Patency rates were calculated based on the time between the date of surgery and when the graft patency was compromised according to duplex ultrasonography. Limb salvage was defined as freedom of any major amputation (i.e., any above-heel amputation) in patients with CLI.
0.50a 74 78 73 0.19b (50; 93) (50; 93) (55; 92) 0.74a 0.92a 13 4 9 4 1 3 0.43a 7 1 6 31 12 19 4 1 3 39
14
25
0.54c
22 23 22 13 5 12
7 7 10 5 1 5
15 16 12 8 4 7
1.00c 0.75c 0.11c 0.73c 0.65c 0.49c
ABI, ankle-brachial index; ASA, American Society of Anesthesiologists; BMI, body mass index; max, maximum; min, minimum. a Pearson chi-squared test. b Independent Student’s t-test. c Fisher’s exact test.
622 Tuijp et al.
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All patients underwent an ABI measurement 3e4 days after surgery. Patients who received a Distaflo Mini-Cuff were administered antiaggregant drugs (acetylsalicylic acid, 80 mg/d). Patients with ASV grafts received oral anticoagulants (acenocoumarol) with a target international normalized ratio between 2.5 and 3.5 during the first 2 postoperative years.4
revascularization. Log-rank tests were used to compare the results of both groups. Univariate analysis was performed using chi-squared, Fisher’s exact, and unpaired Student’s t-tests. For all statistical analyses, a P value less than 0.05 was considered statistically significant.
Follow-Up
Patient Characteristics
To determine graft patency, postoperative follow-up visits of patients who received a Distaflo Mini-Cuff graft occurred 3 months after surgery and included a clinical examination, Duplex ultrasound examination, and an ABI measurement, followed by an ABI measurement after 1, 2, and 3 years. Patients with ASV grafts underwent clinical examination, Duplex ultrasound, and an ABI measurement at 3 and 6 months postoperatively, followed by an ABI measurement every year.4
Gender and Age. Between September 2009 and December 2011, 42 patients (25 men and 17 women) underwent femorocrural bypass surgery (Table I). A total of 28 patients represented the ASV-group, and 14 received a Distaflo Mini-Cuff. The overall mean age was 74 years (range, 50e 93 years); the mean age of the ASV group was 73 years (range, 55e92 years) vs 77.5 years (range, 50e93 years) for the Distaflo Mini-Cuff group. Comorbidities. No difference was seen between both groups with regard to the BMI, arterial hypertension, diabetes, smoking history, cardiac disease, pulmonary disease, renal disease, and carotid disease, and no differences in preoperative American Society of Anesthesiologists (ASA) classification were found. Rutherford Classification and Crural Outflow. No difference in Rutherford classification was seen between the groups, nor was any difference in crural outflow seen before surgery (Table II). Baseline ABI. With regard to the baseline ABI, the mean ABI was 0.4 ± 0.2.
Risk Factors and Comorbidity Risk factors, body mass index (BMI), and adverse events were registered during the admission intake. Risk factor classification and management were determined according to the SVS/ISCVS standards, TASC,1 and American Heart Association/American College of Cardiography7 guidelines. Adverse Events The Association of Surgeons of the Netherlands has agreed on one common definition of adverse events.8 This definition (Appendix) differs from that used in other studies because it was chosen with the explicit goal of excluding subjective judgment about cause and effect, and right and wrong. This definition did not change during the study period. As listed in the Appendix, the adverse events were subdivided into 4 groups: minor, surgical, failed patency, and systemic.9,10 Registration and Statistical Analysis Patient information was registered retrospectively in an electronic patient file used for all patients during their admission intake. Statistical analyses were performed through a computerized software package using IBM SPSS 20.0. Kaplan-Meier and life table survival methods were used to calculate the time curve of the cumulative primary patency, secondary patency, and limb salvage rates determined at regular intervals after primary
RESULTS
Patency, Limb Salvage, Survival No significant difference (Table III and Figs. 1 and 2) were seen in the primary and secondary patency rates of all bypass graft procedures 6 months after surgery. However, patency rates were significantly better in the ASV group (46% vs 14% for the Distaflo Mini-Cuff; P 0.05) after 12 months. Concerning limb salvage rates (Table III,Fig. 3), no significant difference was seen 6 months after revascularization. Limb salvage was significantly better in the ASV group (81% vs 35% for Distaflo Mini-Cuff; P 0.01) after 12 months. A difference in total mortality (Table IV) was seen between both groups (3 deaths for ASV vs 7 for Distaflo Mini-Cuff; P 0.01), but no difference in mortality as seen up to 30 days after surgery. However, 30-day mortality was significantly higher in the population with a Distaflo Mini-Cuff (2 deaths for ASV vs 6 for Distaflo Mini-Cuff; P ¼ 0.01).
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Novel femorocrural ePTFE 623
Table II. Patient peripheral arterial status ePTFE Distaflo Total Mini-cuff ASV (n ¼ 42) (n ¼ 14) (n ¼ 28) P value
Characteristics
Rutherford class 4 5/6 Number of crural outflow arteries before surgery 1 2 3 Location of distal anastomosis Anterior tibial artery Posterior tibial artery Peroneal artery Tibioperoneal truncus Primary/redo ABI Mean preoperative ABI (SD) Mean postoperative ABI (SD)
0.83a 15 27
4 10
11 17 0.77a
12 13 17
5 4 5
7 9 12
18
7
11
0.51a
6
4
2
0.06a
9 9
2 1
7 8
0.43a 0.11a
36/6
11/3
25/3
Fig. 1. Femorocrural bypass graft procedure: primary patency rates.
0.4 (0.2) 0.4 (0.2) 0.4 (0.2) 0.50b 0.7 (0.3) 0.7 (0.4) 0.6 (0.3) 0.49b
SD, standard deviation. a Pearson chi-squared test. b Independent Student’s t-test.
Table III. Cumulative patency rates and limb salvage after femorocrural bypass graft procedure ePTFE Distaflo Total Mini-cuff ASV (n ¼ 42) (n ¼ 14) (n ¼ 28) P value
Primary patency 6 months (%) 12 months (%) Secondary patency 6 months (%) 12 months (%) Limb salvage 6 months (%) 12 months (%)
49 36
41 14
52 46
0.27
Background: This study aims to evaluate early results of a precuffed expanded polytetrafluoroethylene (ePTFE) DistafloÒ Mini-Cuff Bypass Graft versus autologous saphenous vein (ASV) grafting in patients with peripheral arterial obstructive disease (PAOD). Methods: This retrospective single-center study analyzed 42 patients who received a femorocrural bypass graft because of PAOD using an ASV graft (n ¼ 28) or Distaflo Mini-Cuff graft (n ¼ 14). Results: Primary patency rates in the ASV and Distaflo Mini-Cuff groups were 81% and 69%, respectively, after 6 months. Secondary patency rates were 81% and 35%, respectively, after 12 months. The limb salvage rate was 81% in the ASV group vs 65% and 35%, respectively, in the Distaflo Mini-Cuff group after 6 months and 1 year. Conclusions: The ePTFE Distaflo Mini-Cuff is an option for revascularization in the absence of a suitable ASV. However, the performance of this novel graft is not better than that of current ePTFE bypass grafts.
INTRODUCTION Peripheral arterial occlusive disease (PAOD) is a major public health problem and also very common in the western world. The prevalence of symptomatic PAOD seems to increase from approximately 3% in individuals aged 40 years to 6% in patients aged 60 years.1 Approximately 1e3% of all patients with PAOD are diagnosed with critical limb ischemia (CLI).2,3 The primary goals of CLI treatment are to relieve ischemic pain, heal ischemic ulcers, prevent limb loss, improve patient function and quality of life, and prolong patient survival. In the case of revascularization, the first choice is endovascular Department of Surgery, Amphia Hospital, Breda, The Netherlands. Correspondence to: Department of Surgery, Amphia Hospital, Molengracht 21, 4818 CK Breda 5953818, The Netherlands; E-mail: [email protected] Ann Vasc Surg 2014; 28: 620–627 http://dx.doi.org/10.1016/j.avsg.2013.04.024 Ó 2014 Elsevier Inc. All rights reserved. Manuscript received: January 8, 2013; manuscript accepted: April 22, 2013; published online: December 17, 2013.
620
treatment if possible. In the case of surgical revascularization, the autologous saphenous vein (ASV) is still the preferred conduit and provides the best patency and limb salvage rates in femorocrural bypass graft procedures. However, in the absence of a suitable ASV, the use of a small-diameter prosthesis (6 mm) is widely implemented in lower extremity arterial revascularization with a crural distal anastomosis.4,5 A novel precuffed expanded polytetrafluoroethylene (ePTFE) DistafloÒ Mini-Cuff Bypass Graft (Bard Peripheral Vascular Inc., Tempe, AZ, USA),6 with an additional internal diameter reduction of 1 mm over the distal 25 cm of the graft compared with the standard and small cuff precuffed ePTFE Distaflo graft, has been developed for crural bypass surgery. The rationale for this new graft is a smaller distal cuff, which allows a smaller distal anastomosis. Currently, no literature has reported the results of the Distaflo Mini-Cuff graft. This study compared the primary patency, secondary patency, and limb salvage rates of the Distaflo Mini-Cuff graft and ASV bypass grafts in patients
Vol. 28, No. 3, April 2014
Novel femorocrural ePTFE 621
with critical limb ischemia after femorocrural bypass surgery in the 6- and 12-month postoperative periods.
Table I. Patient characteristics and comorbidities before revascularization
MATERIALS AND METHODS
Characteristics
Patients
Gender Male Female Age (y) Mean (min; max) BMI Overweight Obesity ASA classification 2 3 4 Comorbidity Arterial hypertension Diabetes History of smoking Cardiac disease Pulmonary disease Renal disease Carotid disease
ePTFE Distaflo Total Mini-cuff ASV (n ¼ 42) (n ¼ 14) (n ¼ 28) P value
0.18a 25 17
6 8
19 9
Criteria for inclusion were CLI; ischemic rest pain with a resting ankle pressure (AP) less than 40 mm Hg; and gangrene or nonhealing ischemic ulceration with a resting AP less than 60 mm Hg, corresponding with Rutherford categories 4, 5, and 6 of the Society of Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery (SVS/ISCVS) standards, and according to the Trans-Atlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease (TASC)1,7 guidelines. Bypass surgery was performed according to standard vascular techniques. All surgeries were performed by or under the supervision of a vascular surgeon. As listed in Table I, 2 groups of patients were considered according to type of bypass graft: those who were revascularized with a Distaflo Mini-Cuff graft and those who had an ASV bypass graft. Patients who had a missing ipsilateral ASV were revascularized using the contralateral saphenous vein or the lesser saphenous vein if possible. The brachial veins, however, were not considered for use as a bypass graft. The enrolled patients underwent a bypass graft between September 2009 and December 2011. All patients received oral antiplatelet agents and lipidlowering agents to achieve the secondary pharmacologic prevention.
exploration if the ultrasound assessment was inconclusive.
Surgical Workup
Postoperative Care
Before revascularization, the vascular assessment included an ankle-brachial pressure index (ABI), a treadmill test, a venous and arterial Duplex ultrasound assessment, and either a digital subtraction angiography or a magnetic resonance angiography scan. The femorocrural bypass graft procedure was performed according to standard vascular techniques recommended by the SVS/ISCVS and TASC guidelines, preferably using an autologous vein.1,7 Patients were considered for a Distaflo Mini-Cuff graft if both the ipsilateral and contralateral ASVs or the lesser saphenous veins were absent or unsuitable to be used as an autologous bypass graft. Judgment was based on a perioperative ultrasound evaluation or the findings of open surgical
The definition of primary and secondary patency, the decision to intervene, and the type of (re)-intervention were based on the SVS/ISCVS and TASC reporting standards. Primary patency was defined as blood flow through vessels without any previous revascularization procedure for an occlusion or stenosis. Secondary patency was defined as blood flow through a vessel that required reintervention (i.e., embolectomy or thrombolysis). Patency rates were calculated based on the time between the date of surgery and when the graft patency was compromised according to duplex ultrasonography. Limb salvage was defined as freedom of any major amputation (i.e., any above-heel amputation) in patients with CLI.
0.50a 74 78 73 0.19b (50; 93) (50; 93) (55; 92) 0.74a 0.92a 13 4 9 4 1 3 0.43a 7 1 6 31 12 19 4 1 3 39
14
25
0.54c
22 23 22 13 5 12
7 7 10 5 1 5
15 16 12 8 4 7
1.00c 0.75c 0.11c 0.73c 0.65c 0.49c
ABI, ankle-brachial index; ASA, American Society of Anesthesiologists; BMI, body mass index; max, maximum; min, minimum. a Pearson chi-squared test. b Independent Student’s t-test. c Fisher’s exact test.
622 Tuijp et al.
Annals of Vascular Surgery
All patients underwent an ABI measurement 3e4 days after surgery. Patients who received a Distaflo Mini-Cuff were administered antiaggregant drugs (acetylsalicylic acid, 80 mg/d). Patients with ASV grafts received oral anticoagulants (acenocoumarol) with a target international normalized ratio between 2.5 and 3.5 during the first 2 postoperative years.4
revascularization. Log-rank tests were used to compare the results of both groups. Univariate analysis was performed using chi-squared, Fisher’s exact, and unpaired Student’s t-tests. For all statistical analyses, a P value less than 0.05 was considered statistically significant.
Follow-Up
Patient Characteristics
To determine graft patency, postoperative follow-up visits of patients who received a Distaflo Mini-Cuff graft occurred 3 months after surgery and included a clinical examination, Duplex ultrasound examination, and an ABI measurement, followed by an ABI measurement after 1, 2, and 3 years. Patients with ASV grafts underwent clinical examination, Duplex ultrasound, and an ABI measurement at 3 and 6 months postoperatively, followed by an ABI measurement every year.4
Gender and Age. Between September 2009 and December 2011, 42 patients (25 men and 17 women) underwent femorocrural bypass surgery (Table I). A total of 28 patients represented the ASV-group, and 14 received a Distaflo Mini-Cuff. The overall mean age was 74 years (range, 50e 93 years); the mean age of the ASV group was 73 years (range, 55e92 years) vs 77.5 years (range, 50e93 years) for the Distaflo Mini-Cuff group. Comorbidities. No difference was seen between both groups with regard to the BMI, arterial hypertension, diabetes, smoking history, cardiac disease, pulmonary disease, renal disease, and carotid disease, and no differences in preoperative American Society of Anesthesiologists (ASA) classification were found. Rutherford Classification and Crural Outflow. No difference in Rutherford classification was seen between the groups, nor was any difference in crural outflow seen before surgery (Table II). Baseline ABI. With regard to the baseline ABI, the mean ABI was 0.4 ± 0.2.
Risk Factors and Comorbidity Risk factors, body mass index (BMI), and adverse events were registered during the admission intake. Risk factor classification and management were determined according to the SVS/ISCVS standards, TASC,1 and American Heart Association/American College of Cardiography7 guidelines. Adverse Events The Association of Surgeons of the Netherlands has agreed on one common definition of adverse events.8 This definition (Appendix) differs from that used in other studies because it was chosen with the explicit goal of excluding subjective judgment about cause and effect, and right and wrong. This definition did not change during the study period. As listed in the Appendix, the adverse events were subdivided into 4 groups: minor, surgical, failed patency, and systemic.9,10 Registration and Statistical Analysis Patient information was registered retrospectively in an electronic patient file used for all patients during their admission intake. Statistical analyses were performed through a computerized software package using IBM SPSS 20.0. Kaplan-Meier and life table survival methods were used to calculate the time curve of the cumulative primary patency, secondary patency, and limb salvage rates determined at regular intervals after primary
RESULTS
Patency, Limb Salvage, Survival No significant difference (Table III and Figs. 1 and 2) were seen in the primary and secondary patency rates of all bypass graft procedures 6 months after surgery. However, patency rates were significantly better in the ASV group (46% vs 14% for the Distaflo Mini-Cuff; P 0.05) after 12 months. Concerning limb salvage rates (Table III,Fig. 3), no significant difference was seen 6 months after revascularization. Limb salvage was significantly better in the ASV group (81% vs 35% for Distaflo Mini-Cuff; P 0.01) after 12 months. A difference in total mortality (Table IV) was seen between both groups (3 deaths for ASV vs 7 for Distaflo Mini-Cuff; P 0.01), but no difference in mortality as seen up to 30 days after surgery. However, 30-day mortality was significantly higher in the population with a Distaflo Mini-Cuff (2 deaths for ASV vs 6 for Distaflo Mini-Cuff; P ¼ 0.01).
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Novel femorocrural ePTFE 623
Table II. Patient peripheral arterial status ePTFE Distaflo Total Mini-cuff ASV (n ¼ 42) (n ¼ 14) (n ¼ 28) P value
Characteristics
Rutherford class 4 5/6 Number of crural outflow arteries before surgery 1 2 3 Location of distal anastomosis Anterior tibial artery Posterior tibial artery Peroneal artery Tibioperoneal truncus Primary/redo ABI Mean preoperative ABI (SD) Mean postoperative ABI (SD)
0.83a 15 27
4 10
11 17 0.77a
12 13 17
5 4 5
7 9 12
18
7
11
0.51a
6
4
2
0.06a
9 9
2 1
7 8
0.43a 0.11a
36/6
11/3
25/3
Fig. 1. Femorocrural bypass graft procedure: primary patency rates.
0.4 (0.2) 0.4 (0.2) 0.4 (0.2) 0.50b 0.7 (0.3) 0.7 (0.4) 0.6 (0.3) 0.49b
SD, standard deviation. a Pearson chi-squared test. b Independent Student’s t-test.
Table III. Cumulative patency rates and limb salvage after femorocrural bypass graft procedure ePTFE Distaflo Total Mini-cuff ASV (n ¼ 42) (n ¼ 14) (n ¼ 28) P value
Primary patency 6 months (%) 12 months (%) Secondary patency 6 months (%) 12 months (%) Limb salvage 6 months (%) 12 months (%)
49 36
41 14
52 46
0.27
