The International Journal of Lower Extremity Wounds http://ijl.sagepub.com/
Distal Bypasses in Patients With Diabetes and Infrapopliteal Disease: Technical Considerations to Achieve Success Rachael O. Forsythe, Keith G. Jones and Robert J. Hinchliffe International Journal of Lower Extremity Wounds published online 14 August 2014 DOI: 10.1177/1534734614546951 The online version of this article can be found at: http://ijl.sagepub.com/content/early/2014/08/13/1534734614546951
Published by: http://www.sagepublications.com
Additional services and information for The International Journal of Lower Extremity Wounds can be found at: Email Alerts: http://ijl.sagepub.com/cgi/alerts Subscriptions: http://ijl.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav
>> OnlineFirst Version of Record - Aug 14, 2014 What is This?
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546951
research-article2014
IJLXXX10.1177/1534734614546951The International Journal of Lower Extremity WoundsForsythe et al
Review
Distal Bypasses in Patients With Diabetes and Infrapopliteal Disease: Technical Considerations to Achieve Success
The International Journal of Lower Extremity Wounds 1–16 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1534734614546951 ijl.sagepub.com
Rachael O. Forsythe, MBChB, MRCS1, Keith G. Jones, MS , FRCS1, and Robert J. Hinchliffe, MD, FRCS1
Abstract The combination of diabetes and peripheral arterial disease (PAD) is challenging in many ways. The characteristic and complex distal distribution of PAD often encountered in patients with diabetes means that bypass surgery in this context is technically challenging. In addition, many of these patients have a burden of serious comorbidities that must be optimized and managed concurrently. While the authors acknowledge that “achieving success” in distal bypass relies on much more than technical expertise, there are some technical aspects that should be considered when planning surgery on these patients. This article outlines some important issues in the treatment pathway of a patient with diabetes and PAD requiring distal bypass surgery—from selection and optimization of the patient (in the context of a multidisciplinary team) and preoperative workup, to the operative strategy planning, technical tips, and nonoperative adjuncts. These considerations, as well as sound knowledge of the underlying disease process, confounding medical factors and awareness of the difficulty in predicting treatment outcomes, should help maximize the chances of success. Keywords diabetes mellitus, diabetes complication, peripheral arterial disease, vascular surgery Patients with diabetes and peripheral arterial disease (PAD) present specific challenges to the vascular surgeon both in diagnosis and its subsequent management. In this article, the authors will explore technical tips that may improve the success of distal bypass; however, it is imperative to remember that “achieving success” in the treatment of patients with diabetes and PAD relies on much more than good surgical technique. The authors will therefore discuss strategies that may improve technical outcomes and also promote clinical success (such as wound healing), as these 2 entities must be addressed simultaneously in patients with diabetes and PAD. The outcomes of patients with diabetes and PAD depend on a complex interplay of factors including patient comorbidity, presence of infection, neuropathy, and immunological factors, in addition to the effects of impaired tissue perfusion. Coexisting PAD in patients with diabetic foot ulcer (DFU) predicts the failure of wound healing and need for amputation; however, the relationship between successful revascularization and clinical success is neither straightforward nor predictable—repeated interventions are often required to achieve sustained clinical success.1 Moreover, in patients with diabetes and PAD, ulcer healing may occur, or be sustained, despite graft occlusion.
Conversely, successful revascularization may result in very slow wound healing, or early re-ulceration. A recent prospective study of more than 600 patients with DFU and severe PAD who were not suitable for revascularization demonstrated that 50% of those patients healed without major amputation and 17% healed after major amputation,2 suggesting that desirable clinical outcomes such as wound healing and limb salvage are not simply related to vessel patency or revascularization. There is also evidence that higher volume hospitals are associated with better surgical outcomes, particularly in complex operations; a recent systematic review and metaanalysis demonstrated a reduction in amputation and mortality rates after lower limb revascularization surgery3 in high-volume centers. Therefore, even with the most meticulous surgical technique, success is never guaranteed. However, there are 1
St George’s Vascular Institute, St George’s NHS Healthcare Trust, London, UK Corresponding Author: Robert J. Hinchliffe, St George’s Vascular Institute, St George’s Healthcare NHS Trust, Blackshaw Road, London SW17 0QT, UK. Email: [email protected]
Downloaded from ijl.sagepub.com at LAURENTIAN UNIV LIBRARY on October 11, 2014
2
The International Journal of Lower Extremity Wounds
strategies with which the vascular surgeon should be familiar to maximize the potential for successful outcomes (both technical and clinical) in this group of patients that is notoriously difficult to manage. In this article, the authors will explore the various stages involved in distal bypass surgery, beginning with the preoperative workup, selection of patients and procedure, planning the operative strategy, selecting the appropriate inflow and outflow vessels, fundamental surgical techniques, dealing with unexpected events, and ensuring adequate and integrated peri- and postoperative care of these complex patients.
Before the Bypass Patient Selection The first important step in this complex management process is patient and procedural selection. Patients with diabetes and PAD often present late, with tissue loss, which may be an indicator of severe perfusion deficit and limb-threatening ischemia. The concept of “critical limb ischemia” was first described in 1982, when the authors of that article explicitly advised that the term should be used only in patients without diabetes with evidence of limb-threatening chronic limb ischemia, defined as ankle pressure 55 mm Hg) be treated conservatively in the first instance, with optimization of risk factors (control of blood pressure, treatment for hyperlipidemia and plaque stabilization with statins,
good glycemic control, cessation of smoking) combined with biomechanical off-loading, wound care, the use of antibiotics for infection, and routine use of antiplatelets, in the absence of contraindications. In the event of a poor response to medical therapy after an initial trial of 6 weeks, revascularization should subsequently be considered. However, hemodynamic measurements using ABPI alone should not be acted on in isolation, unless the value suggests significant ischemia (150 cm/s, or PSV across the stenosis >2.0),57 and local policy should therefore dictate when to intervene. There is no convincing evidence that surveillance is helpful in patients with synthetic bypass grafts.
Conclusion “Achieving success” in distal bypass surgery is a complex process, relying on much more than good surgical technique. Surgeons embarking on these high-risk bypass procedures in patients with diabetes and PAD should first have a thorough knowledge of the unique disease processes and the differences in pathology, response to treatment and outcomes that affect these patients, when compared to patients without diabetes. They must realize that technical success and clinical success are not always proportional in patients with diabetes and PAD. However, by ensuring careful patient and procedural selection, thorough preoperative workup and combining this with sound knowledge of the various operative techniques, the chances of success should be improved. In addition, understanding the importance of good postoperative care and monitoring should help when making decisions on whether, and when, to re-intervene, in the case of technical failure or clinical deterioration. Declaration of Conflicting Interests
Limb Elevation The limb should be elevated in the early postoperative period to reduce dependent edema and prevent wound dehiscence, which is difficult to manage and may require a rotational flap to restore adequate skin coverage. In patients requiring pedal bypass grafts, admission to hospital for limb elevation a few days prior to surgery is helpful, to reduce peripheral edema in preparation for theatre.
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References
Vein Graft Surveillance Around 20% of vein grafts may become stenosed or occluded within the first 12 months—correction of this may improve outcomes. Vein graft surveillance is commonplace in many units (including the authors’ own), as patients may remain asymptomatic despite graft stenosis or occlusion, which may be difficult to detect on clinical examination. A multicenter randomized controlled trial demonstrated no improvement in health-related quality of life or limb salvage with intensive vein graft surveillance when compared to thorough clinical follow-up (in a population of patients with predominantly femoropopliteal bypasses, most of whom did not have diabetes); however, most units continue to use regular DUS for vein graft surveillance. There is no absolute consensus on the appropriate threshold for intervention for “at-risk” grafts (typically regarded as having >0.2 reduction in ABPI, peak systolic velocity [PSV]
Distal Bypasses in Patients With Diabetes and Infrapopliteal Disease: Technical Considerations to Achieve Success Rachael O. Forsythe, Keith G. Jones and Robert J. Hinchliffe International Journal of Lower Extremity Wounds published online 14 August 2014 DOI: 10.1177/1534734614546951 The online version of this article can be found at: http://ijl.sagepub.com/content/early/2014/08/13/1534734614546951
Published by: http://www.sagepublications.com
Additional services and information for The International Journal of Lower Extremity Wounds can be found at: Email Alerts: http://ijl.sagepub.com/cgi/alerts Subscriptions: http://ijl.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav
>> OnlineFirst Version of Record - Aug 14, 2014 What is This?
Downloaded from ijl.sagepub.com at LAURENTIAN UNIV LIBRARY on October 11, 2014
546951
research-article2014
IJLXXX10.1177/1534734614546951The International Journal of Lower Extremity WoundsForsythe et al
Review
Distal Bypasses in Patients With Diabetes and Infrapopliteal Disease: Technical Considerations to Achieve Success
The International Journal of Lower Extremity Wounds 1–16 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1534734614546951 ijl.sagepub.com
Rachael O. Forsythe, MBChB, MRCS1, Keith G. Jones, MS , FRCS1, and Robert J. Hinchliffe, MD, FRCS1
Abstract The combination of diabetes and peripheral arterial disease (PAD) is challenging in many ways. The characteristic and complex distal distribution of PAD often encountered in patients with diabetes means that bypass surgery in this context is technically challenging. In addition, many of these patients have a burden of serious comorbidities that must be optimized and managed concurrently. While the authors acknowledge that “achieving success” in distal bypass relies on much more than technical expertise, there are some technical aspects that should be considered when planning surgery on these patients. This article outlines some important issues in the treatment pathway of a patient with diabetes and PAD requiring distal bypass surgery—from selection and optimization of the patient (in the context of a multidisciplinary team) and preoperative workup, to the operative strategy planning, technical tips, and nonoperative adjuncts. These considerations, as well as sound knowledge of the underlying disease process, confounding medical factors and awareness of the difficulty in predicting treatment outcomes, should help maximize the chances of success. Keywords diabetes mellitus, diabetes complication, peripheral arterial disease, vascular surgery Patients with diabetes and peripheral arterial disease (PAD) present specific challenges to the vascular surgeon both in diagnosis and its subsequent management. In this article, the authors will explore technical tips that may improve the success of distal bypass; however, it is imperative to remember that “achieving success” in the treatment of patients with diabetes and PAD relies on much more than good surgical technique. The authors will therefore discuss strategies that may improve technical outcomes and also promote clinical success (such as wound healing), as these 2 entities must be addressed simultaneously in patients with diabetes and PAD. The outcomes of patients with diabetes and PAD depend on a complex interplay of factors including patient comorbidity, presence of infection, neuropathy, and immunological factors, in addition to the effects of impaired tissue perfusion. Coexisting PAD in patients with diabetic foot ulcer (DFU) predicts the failure of wound healing and need for amputation; however, the relationship between successful revascularization and clinical success is neither straightforward nor predictable—repeated interventions are often required to achieve sustained clinical success.1 Moreover, in patients with diabetes and PAD, ulcer healing may occur, or be sustained, despite graft occlusion.
Conversely, successful revascularization may result in very slow wound healing, or early re-ulceration. A recent prospective study of more than 600 patients with DFU and severe PAD who were not suitable for revascularization demonstrated that 50% of those patients healed without major amputation and 17% healed after major amputation,2 suggesting that desirable clinical outcomes such as wound healing and limb salvage are not simply related to vessel patency or revascularization. There is also evidence that higher volume hospitals are associated with better surgical outcomes, particularly in complex operations; a recent systematic review and metaanalysis demonstrated a reduction in amputation and mortality rates after lower limb revascularization surgery3 in high-volume centers. Therefore, even with the most meticulous surgical technique, success is never guaranteed. However, there are 1
St George’s Vascular Institute, St George’s NHS Healthcare Trust, London, UK Corresponding Author: Robert J. Hinchliffe, St George’s Vascular Institute, St George’s Healthcare NHS Trust, Blackshaw Road, London SW17 0QT, UK. Email: [email protected]
Downloaded from ijl.sagepub.com at LAURENTIAN UNIV LIBRARY on October 11, 2014
2
The International Journal of Lower Extremity Wounds
strategies with which the vascular surgeon should be familiar to maximize the potential for successful outcomes (both technical and clinical) in this group of patients that is notoriously difficult to manage. In this article, the authors will explore the various stages involved in distal bypass surgery, beginning with the preoperative workup, selection of patients and procedure, planning the operative strategy, selecting the appropriate inflow and outflow vessels, fundamental surgical techniques, dealing with unexpected events, and ensuring adequate and integrated peri- and postoperative care of these complex patients.
Before the Bypass Patient Selection The first important step in this complex management process is patient and procedural selection. Patients with diabetes and PAD often present late, with tissue loss, which may be an indicator of severe perfusion deficit and limb-threatening ischemia. The concept of “critical limb ischemia” was first described in 1982, when the authors of that article explicitly advised that the term should be used only in patients without diabetes with evidence of limb-threatening chronic limb ischemia, defined as ankle pressure 55 mm Hg) be treated conservatively in the first instance, with optimization of risk factors (control of blood pressure, treatment for hyperlipidemia and plaque stabilization with statins,
good glycemic control, cessation of smoking) combined with biomechanical off-loading, wound care, the use of antibiotics for infection, and routine use of antiplatelets, in the absence of contraindications. In the event of a poor response to medical therapy after an initial trial of 6 weeks, revascularization should subsequently be considered. However, hemodynamic measurements using ABPI alone should not be acted on in isolation, unless the value suggests significant ischemia (150 cm/s, or PSV across the stenosis >2.0),57 and local policy should therefore dictate when to intervene. There is no convincing evidence that surveillance is helpful in patients with synthetic bypass grafts.
Conclusion “Achieving success” in distal bypass surgery is a complex process, relying on much more than good surgical technique. Surgeons embarking on these high-risk bypass procedures in patients with diabetes and PAD should first have a thorough knowledge of the unique disease processes and the differences in pathology, response to treatment and outcomes that affect these patients, when compared to patients without diabetes. They must realize that technical success and clinical success are not always proportional in patients with diabetes and PAD. However, by ensuring careful patient and procedural selection, thorough preoperative workup and combining this with sound knowledge of the various operative techniques, the chances of success should be improved. In addition, understanding the importance of good postoperative care and monitoring should help when making decisions on whether, and when, to re-intervene, in the case of technical failure or clinical deterioration. Declaration of Conflicting Interests
Limb Elevation The limb should be elevated in the early postoperative period to reduce dependent edema and prevent wound dehiscence, which is difficult to manage and may require a rotational flap to restore adequate skin coverage. In patients requiring pedal bypass grafts, admission to hospital for limb elevation a few days prior to surgery is helpful, to reduce peripheral edema in preparation for theatre.
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References
Vein Graft Surveillance Around 20% of vein grafts may become stenosed or occluded within the first 12 months—correction of this may improve outcomes. Vein graft surveillance is commonplace in many units (including the authors’ own), as patients may remain asymptomatic despite graft stenosis or occlusion, which may be difficult to detect on clinical examination. A multicenter randomized controlled trial demonstrated no improvement in health-related quality of life or limb salvage with intensive vein graft surveillance when compared to thorough clinical follow-up (in a population of patients with predominantly femoropopliteal bypasses, most of whom did not have diabetes); however, most units continue to use regular DUS for vein graft surveillance. There is no absolute consensus on the appropriate threshold for intervention for “at-risk” grafts (typically regarded as having >0.2 reduction in ABPI, peak systolic velocity [PSV]
