Determining the Need for Surgery

Patients are often referred to surgeons with a suspected surgical diagnosis and the results of supporting investigations in hand. In this context, the surgeon’s initial encounter with the patient may be largely directed toward confirmation of relevant physical findings and review of the clinical history and laboratory and investigative tests that support the diagnosis. A recommendation regarding the need for operative intervention can then be made by the surgeon and discussed with the patient and family members. A decision to perform additional investigative tests or consideration of alternative therapeutic options may postpone the decision for surgical intervention from this initial encounter to a later time. It is important for the surgeon to explain the context of the illness and the benefit of different surgical interventions, further investigation, possible nonsurgical alternatives, when appropriate, as well as what would happen if no intervention were undertaken.

The surgeon’s approach to the patient and family during the initial encounter should be one that fosters a bond of trust and opens a line of communication among all participants. A professional and unhurried approach is mandatory, with time taken to listen to concerns and answer questions posed by the patient and family members. The surgeon’s initial encounter with a patient should result in the patient being able to express a basic understanding of the disease process and the need for further investigation and possible surgical management. A well-articulated follow-up plan is essential.

Perioperative Decision Making

Once the decision has been made to proceed with operative management, a number of considerations must be addressed regarding the timing and site of surgery, type of anesthesia, and preoperative preparation necessary to understand the patient’s risk and optimize the outcome. These components of risk assessment take into account the perioperative (intraoperative period through 48 hours postoperatively) and later postoperative (up to 30 days) period and seek to identify factors that may contribute to patient morbidity during these periods.

Preoperative Evaluation

The aim of preoperative evaluation is not to screen broadly for undiagnosed disease, but to identify and quantify any comorbidity that may affect the operative outcome. This evaluation is driven by findings on the history and physical examination suggestive of organ system dysfunction or by epidemiologic data suggesting the benefit of evaluation based on age, gender, or patterns of disease progression. The goal is to uncover problem areas that may require further investigation or be amenable to preoperative optimization (Table 11-1).¹ Routine preoperative testing is not cost-effective and, even in older adults, is less predictive of perioperative morbidity than the American Society of Anesthesiologists (ASA) status or American Heart Association (AHA)/American College of Cardiology (ACC) guidelines for surgical risk.

Table 11-1 Suggestions for Adult Preoperative Testing

Cardiovascular System

Cardiovascular disease is the leading cause of death in the industrialized world and its contribution to perioperative mortality during noncardiac surgery is significant. Of the 27 million patients undergoing surgery in the United States every year, 8 million, or almost 30%, have significant coronary artery disease or other cardiac comorbid conditions. One million of these patients will experience perioperative cardiac complications, with substantial morbidity, mortality, and cost. Consequently, much of the preoperative risk assessment and patient preparation centers on the cardiovascular system.

Assessment tools for stratification of the cardiovascular portion of anesthetic risk have been available for some time. The premiere example is Goldman’s criteria of cardiac risk for noncardiac surgery (Table 11-3).³ This strategy, designed by multivariate analysis, assigns points to easily reproducible characteristics. The points are then added to yield a total, which has been correlated with perioperative cardiac risk. One of the more important contributions of this work was the inclusion of functional capacity, clinical signs and symptoms, and operative risk assessment to estimate the patient’s overall risk and plan preoperative interventions. This concept has been further refined in the Revised Cardiac Risk Index, which uses six predictors of complications to estimate cardiac risk in noncardiac surgical patients, and is also shown in Table 11-3. In addition, several other investigators have proposed cardiac risk indices; however, many were found to be expensive and time-consuming.

Table 11-3 Cardiac Risk Indices

In an attempt to assess and optimize the cardiac status of patients undergoing noncardiac surgery, a joint committee of the ACC and AHA has developed an easily used tool (Fig. 11-1).⁴ This methodology takes into account previous coronary revascularization and evaluation and clinical risk assessment, divided into major, intermediate, and minor clinical predictors. The next factor taken into account is the patient’s functional capacity, which is estimated by obtaining a history of the patient’s daily activities. The earlier mentioned variables and type of surgery are then used to determine whether the pretest probability can be altered by noninvasive testing.

FIGURE 11-1 Stepwise approach to preoperative cardiac assessment for non-cardiac surgery. HR, Heart rate; MET, metabolic equivalent. Adapted from Fleisher LA, Beckman JA, Brown KA, et al. ACC/AHA 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 2002 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery). Circulation 116:1971–1996, 2007.

*Active cardiac conditions include unstable coronary syndromes, decompensated heart failure (New York Heart Association functional class IV, worsening or new-onset heart failure), significant arrhythmias (high grade atrioventricular block, Mobitz type II block, third degree block, symptomatic ventricular arrhythmias, supraventricular arrhythmias with uncontrolled ventricular rate, symptomatic bradycardia, newly recognized ventricular tachycardia), severe valvular disease (severe aortic stenosis, symptomatic mitral stenosis).

^‡An abbreviated list of METs includes the following: activities such as taking care of yourself, eating, getting dressed, 1 MET; light housework, 4 METs; climbing a flight of stairs or walking up a hill, 5 METs; engaging in strenuous sports, 10 METs.

^§Noninvasive testing may be considered before surgery in specific patients with risk factors if it will change management. Clinical risk factors include ischemic heart disease, compensated or prior heart failure, diabetes mellitus, renal insufficiency, and cerebrovascular disease.

^‖Consider perioperative beta blockade for patient populations in whom this has been shown to reduce morbidity and mortality.

The standard exercise stress test, with or without thallium for perfusion imaging, can be limited by the functional capacity of the patient. Patients not able to exercise to an acceptable stress level may require pharmacologic stress testing with dipyridamole; thereafter, perfusion defects can be assessed via thallium or a dobutamine-induced stress, followed by functional evaluation with echocardiography. Angiography can then be used to define the anatomic abnormalities contributing to the ischemia exactly. Although no large prospective randomized trial has been conducted to determine whether following these guidelines result in improved outcomes for patients, several studies have suggested that it is useful to do so.³

Once these data have been obtained, the surgeon and consultants need to weigh the benefits of surgery against the risk and determine whether any perioperative intervention will reduce the probability of a cardiac event. The intervention usually centers on coronary revascularization via coronary artery bypass or percutaneous transluminal coronary angioplasty but may include modification of the choice of anesthetic or use of invasive intraoperative monitoring. Patients who have undergone a percutaneous coronary intervention with stenting need to have elective noncardiac procedures delayed for 4 to 6 weeks, although the delay may be shortened depending on the type of stent used (drug-eluting versus non–drug-eluting stent).³

The optimal timing of a surgical procedure after myocardial infarction (MI) is dependent on the duration of time since the event and assessment of the patient’s risk for ischemia, by clinical symptoms or noninvasive study. Any patient can be evaluated as a surgical candidate after an acute MI (within 7 days of evaluation) or a recent MI (within 7 to 30 days of evaluation). The infarction event is considered a major clinical predictor in the context of ongoing risk for ischemia. General recommendations are to wait 4 to 6 weeks after MI to perform elective surgery.³

Interventions with medical therapy have also been recommended, in particular beta blocker therapy. The underpinning of this type of therapy centered on decreasing the adrenergic surge associated with surgery and halting platelet activation and microvascular thrombosis. A 1996 study showed that perioperative risk for cardiovascular morbidity and mortality was decreased by 67% and 55%, respectively in ACC/AHA-defined medium- to high-risk patients receiving beta blockers in the perioperative period versus those receiving placebo. Although the benefit was most noticeable in the 6 months after surgery, event-free survival was significantly better in the group that received beta blockers up to 2 years after surgery.⁵ In 2007, the results of another large randomized trial (PeriOperative ISchemic Evaluation—POISE) showed the potential harm of perioperative beta blocker therapy.⁶ The POISE trial enrolled over 8000 patients undergoing noncardiac surgery. Although the results confirmed the reduction in perioperative cardiac events such as myocardial infarction, cardiovascular death, and cardiac arrest, this benefit was offset by an increased rate of stroke and total mortality with perioperative beta blocker therapy. Unlike the prior study, this study started high-dose, extended-release metoprolol on the day of surgery. The results were important enough to stimulate the ACC/AHA to modify their recommendations (Table 11-4).⁷ The current recommendations are to continue beta blockers for those who are on them preoperatively, consider them for high-risk patients (more than one risk factor), titrating to heart rate and blood pressure, and not to give them to low-risk patients.

Table 11-4 American Heart Association/American College of Cardiology Perioperative Focused Update Recommendations

* Class of recommendation is based on the size of the treatment effect combined with an estimate of certainty (precision) of the treatment effect. Clinical risk factors include history of ischemic heart disease, history of compensated or prior heart failure, history of cerebrovascular disease, diabetes mellitus, and renal insufficiency (defined in the revised cardiac risk index as a preoperative serum creatinine level >2 mg/dL).

An easy and inexpensive method to determine cardiopulmonary functional status for noncardiac surgery is the patient’s ability or inability to climb two flights of stairs. Two flights of stairs are needed because it demands more than 4 metabolic equivalents (METs). In a review of all studies of stair climbing as preoperative assessment, prospective studies have shown it to be a good predictor of mortality associated with thoracic surgery.⁸ In major noncardiac surgery, an inability to climb two flights of stairs is an independent predictor of perioperative morbidity, but not mortality.

Pulmonary System

Preoperative evaluation of pulmonary function may be necessary for thoracic or general surgical procedures. Whereas extremity, neurologic, and lower abdominal surgical procedures have little effect on pulmonary function and do not routinely require pulmonary function studies, thoracic and upper abdominal procedures can decrease pulmonary function and predispose to pulmonary complications. Accordingly, it is prudent to consider assessment of pulmonary function for all lung resection cases, for thoracic procedures requiring single-lung ventilation, and for major abdominal and thoracic cases in patients who are older than 60 years, have significant underlying medical disease, smoke, or have overt pulmonary symptomatology. Necessary tests include forced expiratory volume in 1 second (FEV₁), forced vital capacity, and diffusing capacity of carbon monoxide. Adults with an FEV₁ less than 0.8 liter/sec, or 30% of predicted, have a high risk for complications and postoperative pulmonary insufficiency; nonsurgical solutions are sought. Pulmonary resections need to be planned so that the postoperative FEV₁ is higher than 0.8 liter/sec, or 30% of predicted. Such planning can be done with the aid of quantitative lung scans, which can indicate which segments of the lung are functional.

Postoperative pulmonary complications carry with them great cost—estimated to be over $50,000—and increased short- and long-term mortality.^9,10 Risk factors for the development of postoperative pulmonary complications have been identified in a large population of VA patients (Tables 11-5 and 11-6), and recently confirmed in a mixed population. Whereas the VA population was fairly homogeneous, the Patient Safety in Surgery study¹¹ included a more diverse group. Even with the diversity, the rates of pulmonary complications were not much different and the risk factors were very similar. Preoperative pulmonary assessment determines not only factors that confer increased risk but also potential targets to reduce the risk for pulmonary complications. General factors that increase risk for postoperative pulmonary complications include increasing age, lower albumin level, dependent functional status, weight loss, and possibly obesity. Concurrent comorbid conditions such as impaired sensorium, previous stroke, congestive heart failure, acute renal failure, chronic steroid use, and blood transfusion are also associated with increased risk for postoperative pulmonary complications. Specific pulmonary risk factors include chronic obstructive pulmonary disease, smoking, preoperative sputum production, pneumonia, dyspnea, and obstructive sleep apnea.

Table 11-5 Risk Factors for Development of Postoperative Pneumonia and Respiratory Failure*

Table 11-6 Pulmonary Risk Class Assignment

Preoperative interventions that may decrease postoperative pulmonary complications include smoking cessation (within 2 months before the planned procedure), bronchodilator therapy, antibiotic therapy for preexisting infection, and pretreatment of asthmatic patients with steroids. In addition, encouraging exercise preoperatively may improve a patient’s recovery postoperatively. A reasonable recommendation would be to encourage the patients to walk 3 miles in less than 1 hour several times weekly. Perioperative strategies include the use of epidural anesthesia, vigorous pulmonary toilet and rehabilitation, and continued bronchodilator therapy.

Renal System

Approximately 5% of the adult population has some degree of renal dysfunction that can affect the physiology of multiple organ systems and cause additional morbidity in the perioperative period. In fact, a preoperative creatinine level of 2.0 mg/dL or higher is an independent risk factor for cardiac complications. Identification of coexisting cardiovascular, circulatory, hematologic, and metabolic derangements secondary to renal dysfunction are the goals of preoperative evaluation in these patients.

A patient with known renal insufficiency undergoes a thorough history and physical examination, with particular questioning about previous MI and symptoms consistent with ischemic heart disease. The cardiovascular examination seeks to document signs of fluid overload. The patient’s functional status and exercise tolerance are carefully elicited. Diagnostic testing for the patient with renal dysfunction includes an electrocardiogram (ECG), serum chemistry panel, and complete blood count (CBC). If physical examination findings are suggestive of heart failure, a chest radiograph may be helpful. Urinalysis and urinary electrolyte studies are not often helpful in the setting of established renal insufficiency, although they may be diagnostic in patients with new-onset renal dysfunction.

Laboratory abnormalities are often seen in a patient with advanced renal insufficiency. Some metabolic derangements in a patient with advanced renal failure may be mild and asymptomatic and are revealed by electrolyte or blood gas analysis. Anemia, when present in these patients, may range from mild and asymptomatic to that associated with fatigue, low exercise tolerance, and exertional angina. Such anemia can be treated with erythropoietin or darbepoietin preoperatively or perioperatively. Because the platelet dysfunction associated with uremia is often a qualitative one, platelet counts are usually normal. A safe course is to communicate with the anesthesiologist about the potential need for agents to be available in the operating room to assist in improving platelet function. A patient with end-stage renal disease frequently requires additional attention in the perioperative period. Pharmacologic manipulation of hyperkalemia, replacement of calcium for symptomatic hypocalcemia, and use of phosphate-binding antacids for hyperphosphatemia are often required. Sodium bicarbonate is used in the setting of metabolic acidosis not caused by hypoperfusion when serum bicarbonate levels are below 15 mEq/liter. It can be administered in intravenous (IV) fluid as one to two ampules in one liter of a 5% dextrose solution. Hyponatremia is treated by volume restriction, although dialysis is commonly required within the perioperative period for control of volume and electrolyte abnormalities.

Patients with chronic end-stage renal disease undergo dialysis before surgery to optimize their volume status and control the potassium level. Intraoperative hyperkalemia can result from surgical manipulation of tissue or transfusion of blood. Such patients are often dialyzed on the day after surgery as well. In the acute setting, patients who have a stable volume status can undergo surgery without preoperative dialysis, provided that no other indication exists for emergency dialysis.¹² Prevention of secondary renal insults in the perioperative period include the avoidance of nephrotoxic agents and maintenance of adequate intravascular volume throughout this period. In the postoperative period, the pharmacokinetics of many drugs may be unpredictable, and adjustments in dosage need to be made according to pharmacy recommendation. Notably, narcotics used for postoperative pain control may have prolonged effects despite hepatic clearance, and nonsteroidal agents are avoided in patients with renal insufficiency.

Hepatobiliary System

Hepatic dysfunction may reflect the common pathway of a number of insults to the liver, including viral-, drug-, and toxin-mediated disease. A patient with liver dysfunction requires careful assessment of the degree of functional impairment, as well as a coordinated effort to avoid additional insult in the perioperative period (Fig. 11-2).¹³

FIGURE 11-2 Approach to a patient with liver disease. FFP, fresh-frozen plasma; GI, Gastrointestinal; SQ, subcutaneous.

(Adapted from Rizvon MK, Chou CL: Surgery in the patient with liver disease. Med Clin North Am 87:211–227, 2003.)

A history of any exposure to blood and blood products or exposure to hepatotoxic agents is obtained. Patients frequently know whether hepatitis has been diagnosed and need to be questioned about when the diagnosis was made and what activity led to the infection. Although such a history may not affect further patient evaluation, it is important to obtain in case an operative team member is injured during the planned surgical procedure. A review of systems specifically inquires about symptoms such as pruritus, fatigability, excessive bleeding, abdominal distention, and weight gain. Evidence of hepatic dysfunction may be seen on physical examination. Jaundice and scleral icterus may be evident with serum bilirubin levels higher than 3 mg/dL. Skin changes include spider angiomas, caput medusae, palmar erythema, and clubbing of the fingertips. Abdominal examination may reveal distention, evidence of fluid shift, and hepatomegaly. Encephalopathy or asterixis may be evident. Muscle wasting or cachexia can be prominent.

A patient with liver dysfunction should undergo standard liver function tests. Elevations in hepatocellular enzyme levels may suggest a diagnosis of acute or chronic hepatitis, which can be investigated by serologic testing for hepatitis A, B, and C. Alcoholic hepatitis is suggested by lower transaminase levels and an aspartate aminotransferase-to-alanine transaminase ratio (AST/ALT) higher than 2. Laboratory evidence of chronic hepatitis or clinical findings consistent with cirrhosis is investigated with tests of hepatic synthetic function, notably serum albumin, prothrombin, and fibrinogen levels. Patients with evidence of impaired hepatic synthetic function also have a CBC and serum electrolyte analysis. Type and screen are indicated for any procedure in which blood loss could be more than minimal.

In the event of an emergency situation requiring surgery, such an investigation may not be possible. A patient with acute hepatitis and elevated transaminase levels is managed nonoperatively, when feasible, until several weeks beyond normalization of laboratory values. Urgent or emergency procedures in these patients are associated with increased morbidity and mortality. A patient with evidence of chronic hepatitis may often safely undergo surgery. A patient with cirrhosis may be assessed with the Child-Pugh classification, which stratifies operative risk according to a score based on abnormal albumin and bilirubin levels, prolongation of the prothrombin time (PT), and degree of ascites and encephalopathy (Table 11-7). This scoring system was initially used to predict mortality in cirrhotic patients undergoing portacaval shunt procedures, although it has been shown to correlate with mortality in cirrhotic patients undergoing a wider spectrum of procedures as well. Data generated more than 25 years ago showed that patients with Child class A, B, and C cirrhosis had mortality rates of 10%, 31%, and 76%, respectively, during abdominal operations; these figures have been validated more recently.⁸ Although the figures may not represent current risk for all types of abdominal operations, little doubt exists that the presence of cirrhosis confers additional risk for abdominal surgery, proportional to the severity of disease. Other factors that affect outcomes in these patients are the emergency nature of a procedure, prolongation of the PT more than 3 seconds above normal and refractory to correction with vitamin K, and presence of infection.

Table 11-7 Child-Pugh Scoring System

Two common problems requiring surgical evaluation in a cirrhotic patient are hernia (umbilical and groin) and cholecystitis. An umbilical hernia in the presence of ascites is a difficult management problem because spontaneous rupture is associated with increased mortality rates. Elective repair is best after the ascites has been reduced to a minimum preoperatively, although the procedure is still associated with mortality rates as high as 14%. Repair of groin hernias in the presence of ascites is less risky in terms of recurrence and mortality.

Several reports have shown decreased rates of complication with laparoscopic procedures performed in cirrhotic patients. Among the best-described procedures is laparoscopic cholecystectomy performed in patients with Child class A through C. When compared with open cholecystectomy, lower morbidity in terms of blood loss and wound infection has been observed.^13a

Malnutrition is common in cirrhotic patients and is associated with a reduction in hepatic glycogen stores and reduced hepatic protein synthesis. Patients with advanced liver disease often have a poor appetite, tense ascites, and abdominal pain. Attention must be given to appropriate enteral supplementation, as for all patients at significant nutritional risk.

Endocrine System

A patient with an endocrine condition such as diabetes mellitus, hyperthyroidism or hypothyroidism, or adrenal insufficiency is subject to additional physiologic stress during surgery. The preoperative evaluation identifies the type and degree of endocrine dysfunction to permit preoperative optimization. Careful monitoring identifies signs of metabolic stress related to inadequate endocrine control during surgery and throughout the postoperative course.

Perioperative Diabetic Management

The evaluation of a diabetic patient for surgery assesses the adequacy of glycemic control and identifies the presence of diabetic complications, which may have an impact on the patient’s perioperative course. The patient’s history and physical examination document evidence of diabetic complications, including cardiac disease, circulatory abnormalities, and presence of retinopathy, neuropathy, or nephropathy. Preoperative testing may include fasting and postprandial glucose and hemoglobin A1C levels. Serum electrolyte, blood urea nitrogen, and creatinine levels are determined to identify metabolic disturbances and renal involvement. Urinalysis may reveal proteinuria as evidence of diabetic nephropathy. An ECG is considered for patients with long-standing disease. The existence of neuropathy in diabetics may be accompanied by cardiac autonomic neuropathy, which increases the risk for cardiorespiratory instability in the perioperative period.

Management of diabetic patients has evolved in the last decade. The introduction of new drugs for non–insulin-dependent diabetics, in addition to new types of insulin and new insulin delivery systems in insulin-dependent diabetics, has changed how these patients are approached in the perioperative period.

Insulin is available in several types and is typically classified by its length of action (Table 11-8). Rapid- and short-acting insulin preparations are usually withheld when the patient stops oral intake and are used for acute management of hyperglycemia during the NPO period. Intermediate- and long-acting insulin preparations are administered at two thirds the normal evening dose the night before surgery and half the normal morning dose the day of surgery, with frequent bedside glucose determinations and treatment with short-acting insulin, as needed. An infusion of 5% dextrose is initiated the morning of surgery.

Table 11-8 Insulin Types

Insulin pumps are used by some patients as their method of glucose management. These pumps use short-acting insulin (Velosulin) and have a variable delivery rate that can be programmed to simulate endogenous insulin production more closely. On the day of surgery, the patient continues with the basal insulin infusion. The pump is then used to correct the glucose level as it is measured. Patients generally have a correction or sensitivity factor that will decrease their glucose by 50 mg/dL. It is important to know this factor before the planned surgical procedure so that glucose can be managed in the operating room.¹⁴

Patients who take oral hypoglycemic agents (sulfonylureas, such as chlorpropamide and glyburide) typically withhold their normal dose the day of surgery. Patients can resume their oral agent once diet is resumed. An exception is metformin. If the patient has altered renal function, this agent needs to be discontinued until renal function normalizes or stabilizes to avoid potential lactic acidosis.¹⁵ Coverage for hyperglycemia is with a short-acting insulin preparation based on blood glucose monitoring.

Management of Other Endocrinopathies

A patient with known or suspected thyroid disease is evaluated with a thyroid function panel, in particular the thyroid-stimulating hormone (TSH) level. Evidence of hyperthyroidism (very low TSH level) is addressed preoperatively and surgery is deferred until a euthyroid state has been achieved, when feasible. These patients need to have their electrolyte levels determined and an ECG performed as part of their preoperative evaluation. In addition, if the physical examination suggests signs of airway compromise from a large goiter, further imaging may be warranted. A patient with hyperthyroidism who takes antithyroid medication such as propylthiouracil or methimazole is instructed to continue this regimen on the day of surgery. The patient’s usual doses of beta blockers or digoxin are also continued. In the event of urgent surgery in a thyrotoxic patient at risk for thyroid storm, a combination of adrenergic blockers and glucocorticoids may be required; these are administered in consultation with an endocrinologist. Patients with newly diagnosed hypothyroidism generally do not require preoperative treatment, although they may be subject to increased sensitivity to medications, including anesthetic agents and narcotics. Severe hypothyroidism (high TSH level) can be associated with myocardial dysfunction, coagulation abnormality, and electrolyte imbalance, notably hypoglycemia. Severe hypothyroidism needs to be corrected before elective operations. It should also be considered for a severely ill patient who is not recovering from surgery in a normal fashion.

A patient with a history of steroid use may require supplementation for a presumed abnormal adrenal response to perioperative stress (Box 11-1). Patients who have taken more than 5 mg of prednisone (or equivalent)/day for more than 3 weeks within the past year are considered at risk when undergoing major surgery. Lower doses of steroid or minor procedures are not generally associated with adrenal suppression.

BOX 11-1 Adapted from Schiff RL, Welsh GA: Perioperative evaluation and management of the patient with endocrine dysfunction. Med Clin North Am 87:175–192, 2003; and Kohl, BA, Schwartz S: Surgery in the patient with endocrine dysfunction. Med Clin North Am 93:1031–1047, 2009.

Perioperative Supplemental Glucocorticoid Regimens

No HPAA Suppression

Less than 5 mg of prednisone or equivalent/day for any duration

Alternate-day single morning dose of short-acting glucocorticoid of any dose or duration

Any dose of glucocorticoid for less than 3 wk

• Rx: Give the usual daily glucocorticoid dose during the perioperative period.

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