Fundamentals of Spine Surgery

Published on 02/04/2015 by admin

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Chapter 25 Fundamentals of Spine Surgery

Harminder Singh, James S. Harrop

Decision-Making Process

Clinical decision making is one of the most challenging tasks for any physician, particularly for spine surgeons. Multiple factors influence the surgical and medical decision-making process. Although the patient is the surgeon’s first priority, other factors such as financial and social pressures also must be taken into consideration. This chapter addresses some of the fundamentals of this process, including patient selection, informed consent, surgical planning, biomechanics, technology, and medical economics.

Patient Selection

Patient selection is the most important and difficult task in the surgical treatment of spine disorders. A technically perfect operation in the wrong patient might fulfill the surgical goals of the procedure but is unlikely to resolve the patient’s initial complaints and deficits. Unfortunately, a proper study investigating the indications for spine surgery is not only difficult to design but also equally difficult to execute.

The Spine Patient Outcome Research Trial (SPORT) highlights some of the difficulties in executing a randomized, multicentric trial.¹^–³ SPORT was the first comprehensive study to look at different ways of treating low back and leg pain and the effectiveness of those treatments. Even though this was a prospective, randomized trial, the amount of crossover between the surgical and nonsurgical arms ultimately rendered the analyses nonrandomized. Additionally, blinding was not possible in a surgical trial, which could have also introduced several confounders into the analyses.

Consequently, there is little evidence to guide the spine surgeon concerning operative indications, techniques, and timing of surgery. This lack has impeded the ability of physicians to collect and analyze clinically relevant data. Without such data to guide clinical decision making, the problem of patient selection and management strategy determination will remain difficult.

Previous attempts at analyzing the natural history and postsurgical outcome of spine disorders have yielded equivocal results, primarily because most studies were done retrospectively, and the data generated were, at best, level 2 or 3 evidence. Currently, there is a drive in the spine community to provide more prospective analyses, comparing treatment strategies along with outcome analyses using recognized scales, such as the Oswestry Low Back Pain Disability Questionnaire and the 36-Item Short Form Health Survey (SF-36). These analyses report patient satisfaction and quality of life after procedures, rather than fusion rate and neurologic recovery. The former are the ultimate goals and the true determinants of treatment efficacy.

In addition to increasing patient satisfaction and quality of life, other factors such as personal or financial considerations, defensive practice strategies, and third-party payers have motivated surgeons to address the challenges and difficulties of patient selection. In particular, third-party payers are reluctant to reimburse physicians, hospitals, and patients for procedures that lack clear indications or documented evidence of efficacy. In the current environment of cost-containment, surgeons are increasingly pressured by outside influences to demonstrate that they practice safe and appropriate surgery, by documenting their surgical outcomes. Although the motivations that underlie these powerful forces often are not altruistic, it should be evident that the results of so-called outcome research will benefit both the patient and the surgeon.

The excellent design and timely execution of carotid endarterectomy studies such as the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Atherosclerosis Study (ACAS) provide a paradigm for the potential benefits of outcomes research.^4,⁵ These studies clearly defined objective criteria for surgical treatment, based on risk and benefit ratios. Although outcome assessment is obviously more straightforward for carotid endarterectomy than spine surgery, the carotid endarterectomy trials nevertheless serve as a reminder of the powerful influence such trials can exert on surgical practice. These trials not only have established the safety and efficacy of the procedure itself, but also have provided unambiguous guidelines for patient selection. However, the suboptimal prospective study of extracranial-to-intracranial bypass for ischemic stroke, which concluded that surgical treatment was less effective than medical therapy, does illustrate some weaknesses of this type of study.⁶

Newer studies such as the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) and the Carotid Occlusion Surgery Study (COSS) are using the prospective, randomized study design in an attempt to generate level 1 data to guide evidence-based medicine practices.

Consent for Surgery

When the surgeon’s clinical judgment supports surgical treatment for a disorder, the traditional relationship between the patient and the surgeon has been such that the surgeon recommends surgery and the patient, if willing, agrees. The modern “legal” contract that attempts to formalize this interaction is the consent for surgery form. This form is used to document that the patient has agreed to allow the surgeon to perform an operation, with an understanding of the risks, benefits, and alternative treatment options. This form is what most patients and surgeons conceptualize as consent for surgery.

However, this consent for surgery form is not just a piece of paper. It manifests the patient’s right to determine how he or she will be treated. Physicians’ recognition of this distinction has led to a more thoughtful and meaningful agreement or consent that satisfies stringent ethical and legal requirements. This is what is referred to as informed consent.

Informed Consent

Patient autonomy, the most fundamental of all patients’ rights, is portrayed through the informed consent. It is the permission a patient grants to a physician to administer a treatment. The patient should understand the rationale for the treatment, the alternatives to the treatment, the nature of the treatment, the intended result of the treatment and its chances for success, and the nature and risks of adverse consequences of the treatment. During the interval of informed consent, the physician is able to define the problem facing the patient, based on limited prospective studies, suspected natural history course, alternative treatments, and risks and benefits, along with the goals of surgical treatment. This conference also allows the physician to address any fears and expectations the patient might have about his or her disease process and possible treatment schemes.

In the context of clinical decision making, several objections have been raised regarding the logic, and even the possibility, of informed consent. The defense of the doctrine of informed consent is beyond the scope of this chapter. However, a few points in response to objections about informed consent are worthy of consideration. Some argue that because the physician possesses a superior knowledge of the medical situation and proposed procedures, the patient cannot properly decide about informed consent. This argument is based on a misconception that gives undue primacy to patient understanding. In fact, one’s right not to be assaulted is not conditional on one’s understanding of the motivation for the assault. In the context of clinical decision making, then, it seems reasonable to argue that a patient’s limited understanding of the consequences of the choice does not abrogate the right to decide what is to be done.

Several studies have shown that patients often are unable to recall the content of the information that the physician conveyed during the session at which informed consent was supposedly obtained.⁷^–⁹ Sometimes these scenarios are the basis for legal claims against unsuspecting physicians, who are accused of not informing the patient adequately of potential complications. Physicians can avoid these confrontations by carefully documenting their conversations with patients and their families in the medical record, indicating both the time and the date of the conversation as evidence that it occurred before any intervention. Note that this documentation should be in addition to written patient consent. However, legal repercussions aside, the demonstration that patients often do not remember information provided by physicians is certainly not a logical argument against the virtue of informed consent. There are many instances in life when one is unable to recall the reasons or motivations for making even the most important decisions.

Finally, the patient should be afforded the right to make a decision that is not consistent with the best medical prognosis. Many factors must be considered in every medical decision. This is especially true of such an important decision as the one to undergo surgery, which is influenced by a wide array of circumstances and beliefs, such as occupation, lifestyle, state of health, family, and the patient’s idea of what constitutes a life that is worth living.