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| June 2008 |
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An official publication of the American College of Surgeons |
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EDITORIAL CHAIR | |
| Wiley W. Souba, MD, ScD, FACS | ||
| EDITORIAL BOARD | ||
| Mitchell P. Fink, MD, FACS | William H. Pearce, MD, FACS | |
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Gregory J. Jurkovich, MD, FACS | John H. Pemberton, MD, FACS |
| Larry R. Kaiser, MD, FACS | Nathaniel J. Soper, MD, FACS | |
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name to send email to the editor. |
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| IN THIS ISSUE |
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A New Publisher for ACS Surgery |
| Benchmarking Surgical Outcomes |
| Prevention of Postoperative Infection |
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Aortoiliac Reconstruction |
| CME
Program |
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| THE BEST SURGICAL THINKING |
DOI 10.2310/7800.2008.NCjun
The American College of Surgeons recently entered into a long-term agreement with BC Decker Inc as the new publisher of ACS Surgery. Brian Decker and the editors are very interested in continuing to elevate the high quality of ACS Surgery and making this a win-win relationship through the sharing of ideas and materials and joint promotion of the College and ACS Surgery. We want to see ACS Surgery serve as a resource to enhance the quality of surgical practice and to increase membership in the American College of Surgeons.
The ongoing evolution of ACS Surgery offers many advantages and opportunities for its readers. As a current subscriber, you should know that ACS Surgery was designed to be innovative and cutting edge. Our commitment to you is to continue this tradition. We will expand and strengthen our efforts to integrate and communicate principles and guidelines for effective surgical practice in cooperation with the College to assure subscribers that important new studies, therapies, and procedures are systematically incorporated into ACS Surgery as rapidly as possible.
Of course, one of the key strengths of ACS Surgery, the expertise of its editorial board members and authors, will continue to be our anchoring foundation. Other features that have established this text as an expert reference will also remain unchanged, including our authoritative approach, renowned illustration style, and subscriber services such as monthly updates, as well as our convenient and economical continuing medical education (CME) program.
The monthly updates of the text, the monthly newsletter, What's New in ACS Surgery, and the monthly CME program provide students, physicians in training, residency programs, and busy surgeons with an organized and easy to grasp educational program to stay current. ACS Surgery serves as an excellent pathway for maintenance of certification, and many residency programs now subscribe to ACS Surgery's weekly curriculum program. There are many opportunities to advance these ideas and products jointly.
Although we focus on content development for the needs of practicing general surgeons, ACS Surgery is of equal value for surgical specialists who need to keep up with topics in general surgery. We also see a substantial opportunity to use ACS Surgery in recruiting new international members to the College.
Many have asked, " Is there a future for medical textbooks?" or " If I buy it, how soon will it be outdated?" Certainly, traditional textbooks are viewed by many as " an endangered species" with the ease of storage, organization, and retrieval of information worldwide via the Internet. On the other hand, medical publishing far surpasses the capacity of individuals to read, digest, and remember current information. There is a greater need than ever for surgeons and other practitioners to have current, well-written, reliable information in a format that makes it easy to use. At ACS Surgery, we promise to do our best to keep our succinctly written comprehensive text current. We intend for it to provide you with the most current and up-to-date surgical thought available to help guide you through difficult decisions and procedures.
ACS Surgery complements the education materials and publications of the College. Because we produce ACS Surgery on a continuing basis, like a journal, with a capacity to update all materials at any time, ACS Surgery is particularly valuable for CME, for maintenance of certification, and as part of a curriculum for graduate medical education. BC Decker Inc will uphold the traditions and excellence of ACS Surgery. In the months ahead, we will share with you new ideas involving design, referencing, indexing, digital hosting, CME, and other features to increase the value of being a subscriber to ACS Surgery.
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| THIS MONTH'S UPDATES |
Elements of Contemporary Practice
3 Benchmarking Surgical Outcomes
DOI 10.2310/7800.SECPC03
Public reporting programs, public use administrative databases, and clinical registries all offer surgical outcomes data to benchmark hospital and even surgeon-specific performance.
Interest about surgical outcomes is growing. Patients want to make informed decisions about where and from whom to receive surgical care, and public and private payers want information about surgical performance for their value-based purchasing initiatives.
Public Reporting Programs
The most readily available source of surgical outcomes data is Internet-based public reporting programs. Currently, those based on clinical data are limited to cardiac surgery. Some states administer longitudinal clinical registries and regularly release information on risk-adjusted mortality rates for coronary artery bypass surgery. All states release hospital-specific performance data, but only some report surgeon-specific information.
Public reporting programs related to other surgical procedures generally rely on administrative data. The most widely available source of surgical outcomes data comes from proprietary rating firms.
Public Use Administrative Databases
Rather than relying on outside analysis, surgeons can obtain administrative data and do it themselves. For example, surgeons can obtain data from the Nationwide Inpatient Sample, a database containing information from approximately 8 million hospital admissions annually.
Administrative data have many limitations for benchmarking outcomes, but the most important limitations relate to problems with accuracy, completeness, and clinical precision of coding.
Clinical Registries
The ideal source of information for benchmarking surgical outcomes is prospective, clinical outcomes registries. Outcomes data from these sources are not reported publicly but instead provide confidential feedback on performance to hospitals and surgeons.
A visible and powerful source of benchmarking information is the National Surgical Quality Improvement Program (NSQIP). Preoperative risk factors, intraoperative variables, and 30-day postoperative mortality and morbidity outcomes for patients undergoing major surgery are submitted. Risk-adjusted morbidity and mortality results for each hospital are calculated semiannually and are reported as observed versus expected ratios. Nonetheless, the NSQIP is expensive to administer, and risk adjustment is not based on risk factors specific to individual procedures.
The Society of Thoracic Surgeons national database is the best source for benchmarking outcomes with cardiac surgery. Its database includes clinical data on more than 70% of all adult cardiothoracic operations performed annually in the United States. A major weakness is the lack of external auditing to ensure the accuracy and completeness of outcomes data submitted by hospitals.
The National Cancer Data Base (NCDB) tracks information related to the treatment and outcome of cancer patients. About 1,400 hospitals nationwide submit data to the NCDB, which currently captures approximately 75% of incident cancer cases in the United States. Individuals at approved cancer centers can access benchmark reports that summarize data from the user's own center and comparisons with state, regional, or national data. However, data are not externally audited to ensure accuracy and completeness.
Currently, approximately 556 hospitals submit data to the National Trauma Data Bank, including 70% of Level I– and 53% of Level II–designated trauma centers. Data submission is voluntary and not externally audited.
Two programs track outcomes with bariatric surgery. Clinical registries of the ACS Bariatric Surgery Center Network Program and the Surgical Review Corporation support hospital accreditation and " centers of excellence" designations in bariatric surgery.
Limitations of Surgical Benchmarking
All surgical benchmarks have common limitations. The first relates to sample size. Although the benchmarks are usually based on large numbers and are thus statistically robust, the outcomes of hospitals and surgeons assessing their own performance against these benchmarks are not, particularly at the level of individual procedures. When sample sizes are too small, it may be difficult to determine whether complication rates higher than the benchmark reflect genuine problems or simply chance.
Generalizability is another limitation. Owing to the individual characteristics of each database, different data sets yield different mortality estimates. Although none of these mortality estimates are " wrong," surgeons must recognize that risk estimates depend on the composition of each database and may not be generalizable to their own practice.
1 Basic Surgical and Perioperative Considerations
1 Prevention of Postoperative Infection
DOI 10.2310/7800.S01C01
Surgical site infections have no single cause, but can be systematically reduced by stricter attention to the bacteria that cause SSIs and various environmental and host factors.
Historically, wound infection control depended on antiseptic and aseptic techniques directed at coping with the infecting organism. In the 19th century and the early part of the 20th century, wound infections had devastating consequences and a measurable mortality. Even in the 1960s, before the correct use of antibiotics and the advent of modern preoperative and postoperative care, as many as one quarter of the surgical ward patients might have had wound complications. These infections have been reduced, but continue to have huge clinical and financial implications.
The Centers for Disease Control and Prevention uses the term surgical site infection (SSI) to take into consideration the operative site as a whole. SSIs can be classified as superficial incisional (involving only skin and subcutaneous tissue), deep incisional (involving deep soft tissue), and organ or space (involving anatomic areas that are opened or manipulated in the course of the procedure).
Current risk assessments integrate the three determinants of infection: bacteria, local environment (including surgeon factors), and systemic host defenses (patient factors).
Role of Bacteria, Surgeon Factors, and Patient Factors in SSIs
Without an infecting agent, no infection will result. Accordingly, most of what is known about bacteria is put to use in major efforts directed at reducing their numbers by means of asepsis and antisepsis. Endogenous bacteria are a more important cause of SSI than exogenous bacteria. In clean-contaminated, contaminated, and dirty-infected operations, the source and the amount of bacteria are functions of the patient's disease and the specific organs being operated on.
The most obvious pathogenic bacteria in surgical patients are gram-positive cocci (e.g., Staphylococcus aureus and streptococci). S. aureus—in particular, MRSA—is a major cause of SSI. The preoperative hospital stay also contributes to wound infection rates. The usual explanation is that either more endogenous bacteria are present or commensal flora is replaced by hospital flora.
Most of the local factors that make a surgical site favorable to bacteria are under the surgeon's control, and the reach extends beyond good hand-washing practices. For example, the use of drains that a surgeon chooses varies widely and is very subjective. Using a closed suction drain reduces the potential for contamination and infection. Also, in most studies, contamination increases with the duration of the operation. Nonetheless, it is only expeditious operation that is appropriate, not speed. Finally, the use of electrocautery devices has been associated with an increase in the incidence of superficial SSIs unless used properly.
The human systemic response is designed to control and eradicate infection, but can be overwhelmed by certain factors. Patients at risk for wound infection are those with three or more concomitant diagnoses, those undergoing a clean-contaminated or contaminated abdominal procedure, and those undergoing any procedure expected to last longer than 2 hours. Also increasing the risk of SSI are shock, advanced age, transfusion, and the use of steroids and other immunosuppressive drugs, including chemotherapeutic agents.
Steps Necessary to Reduce SSIs
Antibiotics have not always prevented SSI successfully. Although surgeons were quick to appreciate the possibilities of antibiotics, the efficacy of antibiotic prophylaxis was not accepted until the following was unequivocally proved:
They are most effective when given before inoculation of bacteria.
They are ineffective if given 3 hours after inoculation.
They are of intermediate effectiveness when given between these times.
Significant advances in the control of wound infection during the past several decades are linked to a better understanding of the steps necessary to reduce SSIs overall:
Keeping the bacterial contamination as low as possible via asepsis and antisepsis, preoperative preparation of patient and surgeon, and antibiotic prophylaxis.
Maintaining local factors in such a way that they can prevent the lodgment of bacteria and thereby provide a locally unreceptive environment.
Maintaining systemic responses at such a level that they can control the bacteria that become established.
6 Vascular System
12 Aortoiliac Reconstruction
DOI 10.2310/7800.S06C12
Surgeons can choose a revascularization approach to ameliorate aortoiliac occlusive disease.
Symptomatic aortoiliac occlusive disease is the consequence of a diffuse atherosclerotic process exacerbated by smoking, hypertension, hypercholesterolemia, and diabetes. The resultant narrowing of the aorta and the iliac vessels impairs circulation into the pelvis and the lower extremities, causing complaints such as impotence and claudication and even ulceration or gangrene. Choosing a surgical revascularization approach is based on anatomic constraints and comorbid conditions.
Preoperatively, the physician should determine the extent of occlusive disease by measuring lower extremity blood flow with arterial waveforms and ankle-brachial indices. An imaging study is also required to guide revascularization. If an extra-anatomic bypass is anticipated, ancillary tests, including bilateral arm blood pressure measurements and computed tomography scans of the chest, abdomen, or pelvis may be necessary. A standard cardiac risk assessment is mandatory, and the extent of testing is tailored to the level of cardiac risk.
Operative Techniques for Aortoiliac Reconstruction
Although localized aortoiliac endarterectomy is less commonly performed today than it once was, it remains useful for a subgroup of patients with focal aortic bifurcation disease. The classic candidate has minimal disease of the infrarenal abdominal aorta and the external iliac arteries, but a severely diseased and narrowed aortic bifurcation.
Iliofemoral bypass, already an uncommon procedure, has now largely been supplanted by advances in percutaneous endoluminal techniques. Nevertheless, it is still used and is worth knowing. One limitation is that aortoiliac occlusive disease typically causes diffuse aortic and bilateral iliac artery narrowing. Iliofemoral bypass is most suitable for those rare patients who have isolated unilateral external iliac artery disease.
Before the application of percutaneous balloon angioplasty and stenting, aortofemoral bypass grafting was the revascularization operation of choice for patients with diffuse aortoiliac occlusive disease. This operation is still favored by many, and it yields excellent long-term patency.
A thoracofemoral bypass is ideal for a small subgroup of patients, comprising (1) those with an occluded old aortofemoral bypass graft, (2) those with a so-called lead-pipe calcified infrarenal aorta that is unusable as an inflow source, and (3) those with a so-called hostile abdomen. Candidates must have adequate pulmonary reserve and be able to tolerate a thoracotomy. There is risk of paralysis.
Axillofemoral bypass is ideally suited to elderly patients who cannot tolerate an aortic operation. The hemodynamic changes occurring during the operation are minimal, and recovery from the three small incisions is generally quick.
A femorofemoral crossover bypass is well suited to patients who have unilateral complete occlusion or a diffusely diseased iliac system but have a relatively normal contralateral iliac system. It is performed similarly to an axillofemoral bypass, but without the axillary anastomosis.
In terms of endovascular therapy, the use of percutaneous balloon angioplasty and stenting for the treatment of peripheral vascular disease has grown exponentially since its introduction in the 1990s. With regard to short-term results, patients experience less pain, recover more quickly, and regain function earlier.
Complications of Aortoiliac Revascularization
Bleeding, distal embolization, graft thrombosis, and graft infection are associated with all revascularization procedures. Late graft infection, recurrent disease, and pseudoaneurysm formation are known long-term complications. Some complications are unique to one or more of the procedures but do not arise with the others.
Overall Long-term Survival in Patients with Symptomatic Aortoiliac Disease
Regardless of which operation is performed, the subsequent outcome should be immediate relief of presenting symptoms. Unfortunately, overall long-term survival in patients with symptomatic aortoiliac occlusive disease is not improved by operative management and is typically 10 to 15 years less than that in a normal age-matched group. The most significant long-term cause of death is atherosclerotic cardiac disease, underscoring the importance of a thorough preoperative cardiac evaluation.