Complications in Vascular and Endovascular Surgery

How to avoid them and how to get out of trouble

Earnshaw, Jonothan J, Wyatt, Michael G, Earnshaw, Jonothan J, Wyatt, Michael G

• Publisher: tfm Publishing Ltd
• Year: 2012
• Print ISBN:
  9781903378809
• eBook ISBN:
  9781908986788
• Topic: Medicine
• Subtopic: Medical Theory, Practice & Reference

The aim of this book is to help clinicians to reduce the risk of complications after vascular and endovascular surgery. Whilst it is a surgical truism that the surgeon who does the most operations has the most complications (an acknowledgement of the fact that all vascular and endovascular procedures are potentially hazardous, and some extremely so), some surgeons seem to have more complications than others. This book is for all surgeons and radiologists who accept the challenge continually to improve their results. Each chapter is authored by an experienced (endo)vascular specialist who will have witnessed firsthand the perils and pitfalls of vascular procedures. They have seen all the complications, and even occasionally made errors of judgement. The chapters are full of information to help the reader avoid similar hazards in future. We live in a world of high patient expectation, where complications are seen as 'someone's fault'. Clinicians are familiar with innovations such as outcomes audit and assessment, procedural governance and quality improvement programmes. There is pressure to show progressive improvement. First class surgery is a combination of knowledge and skill and perhaps just a little luck, though as is oft quoted 'the more you practice, the luckier you get'. The information in this book will provide insights, protocols, and tips and tricks to minimise the risks of procedures in vascular and endovascular surgery. It is therefore essential reading for anyone who treats patients with vascular disease.

Part 1

The general complications of vascular and endovascular surgery

Chapter 1

How do complications influence outcome?

Sidhartha Sinha MA MRCS, Clinical Research Fellow in Vascular Surgery

Peter Holt PhD FRCS, Clinical Lecturer in Vascular Surgery

St George’s NHS Trust, London, UK

Introduction

Vascular surgical procedures carry an intrinsic risk, since they are performed on patients with multiple, often severe comorbidities ¹. It is unrealistic to expect no postoperative complications in this cohort of patients therefore, and the way in which adverse events are handled is important in determining final peri-operative and longer-term outcomes. As high quality is central to any modern surgical service, an understanding of the reporting and interpretation of outcomes data, and the impact of peri-procedural complications on outcomes is important for the vascular specialist. The ways in which the detection and management of complications can lead to quality improvements in vascular surgery are paramount.

The quality agenda and outcomes assessment

The most recent report on health care delivery in the National Health Service in the UK places critical importance on the achievement of high quality ². In defining quality, the report identifies three key domains (Figure 1) and builds on an existing model of clinical governance to propose the necessary means to achieve high quality health care. It is noteworthy that, in contrast to previous iterations, the most recent changes propose to drive up quality standards predominantly by improvements in (and the transparent publication of) clinical outcomes ^{3, 4}.

Figure 1. Darzi model of the domains of high quality health care – with specific examples. * European Quality of Life 5-dimension questionnaire.

Which outcomes to measure in vascular surgery?

Understanding how complications influence outcomes requires a knowledge of which current metrics are informative. In general, outcome measures are visible and quantifiable endpoints of clinical pathways that are commonly employed in the assessment of quality, underpinning quality improvement frameworks and informing the commissioning of health care services. An increasing number of quality metrics are being proposed to assess surgical care. Critically, when each is reported, it should be placed into context such that the reported outcome is valid for the specific condition or procedure assessed.

Mortality

Postoperative mortality rates are objective and easily measurable. Despite some conceptual and methodological difficulties associated with their use, they are the most commonly employed outcomes measure in studies assessing health care quality and remain the most valid proxy ^5-7. Postoperative mortality can be reported at differing intervals; commonly used variations are in-hospital, 30-day and 1-year mortality rates. Increasingly, longer-term mortality rates are reported in the literature. Although in-hospital mortality is reliably quantified, it may be confounded by institutional, political and financial factors favouring more rapid discharge ⁸. One-year mortality is also susceptible to confounding by factors unrelated to the structure and process of care delivered, such as the extent/nature of underlying disease and social circumstances. It may, however, be a more meaningful outcome statistic from the patient’s point of view ^{8, 9}.

Morbidity

Although postoperative morbidity refers to untoward or adverse events after surgery, traditionally this has been interpreted from a clinical viewpoint. Thus postoperative morbidity has become synonymous with postoperative complications, including deep venous thrombosis and surgical site infection ¹⁰. A more holistic appraisal of the concept envisages a model where several other inter-related metrics could be interpreted as components of morbidity: reintervention (return to theatre) rate, length of stay, readmission rate and discharge destination (Figure 2) ⁵.

Figure 2. Inter-relationship between components of postoperative mortality and morbidity. LOS = length of stay.

Complication rates

There is increasing interest in the use of postoperative complication rates as an index of quality. Concerns remain over the lack of standardisation in defining and recording complications; however, postoperative complication rates in modern surgical practice tend to be sufficiently frequent to yield stable statistical estimates when used as outcome measures ⁸. Furthermore, it has been demonstrated that postoperative complications are significantly related to other outcome measures such as mortality and hospital length of stay ^{11, 12}.

Readmission rates

Emergency readmission has been defined as a quality metric by the UK Department of Health for a number of surgical procedures, including abdominal aortic aneurysm (AAA) repair ⁵. This is based on the assumption that unplanned readmission reflects a deficiency in the quality of care during the index admission. Retrospective studies from both North America and the UK have shown that patients requiring either medical or surgical readmission at 30 days, or even up to 1 year after open or endovascular aneurysm repair (EVAR) had higher mortality than patients not requiring readmission ^{5, 13}. Yet readmission rates vary considerably between surgical specialties and are highly influenced by case-mix, being much more common in the elderly and those with chronic medical conditions ¹⁴. Within vascular surgery, most readmissions are related to medical comorbidities. Context is therefore crucial when publishing outcomes, allowing the reason for readmission (surgical, medical or social) to be understood and appropriately reimbursed.

Reintervention rates

Surgical reintervention rates have been used as secondary outcome measures in clinical studies including the EVAR trials ^{15, 16}. They have been proposed as surrogate quality markers in AAA repair, as the need for reintervention may reflect technical failure during surgery and poor patient selection ⁵. The impact of reintervention...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• Contents
• Contributors
• Foreword
• Introduction
• Part 1: The general complications of vascular and endovascular surgery
• Part 2: Complications related to specific vascular and endovascular procedures