2018-19 Section 7-Neoplastic and Inflammatory Diseases of the Head and Neck eBook

Eskander et al

prevent the formation of an unstable regression model. To further ensure model stability, we used a conservative approach to variable inclusion, ensuring no more than 1 variable for every 10 events (1:10 ratio) for each regression model. All regression model results are reported as a vari- able estimate with associated standard error and P value. Statistical significance was defined by a 2-sided P value of .05. All analyses were performed using SAS version 9.2 (SAS Institute, Cary, North Carolina). Results Study Subjects The characteristics of the 515 patients are presented in Table 1 . These cohort characteristics have been previously reported in a separate study assessing quality metrics in patients receiving head and neck free flap reconstruction. 7 Our cohort had a mean (SD) age of 60.1 (12.8) years, and 66% were male. A significant proportion (28%) had primary radiotherapy with or without chemotherapy, 33% of tumors were recurrent, and the cohort had a high mean (SD) age- adjusted CCI at 5.0 (2.3). Seventy-eight percent of patients were current or previous smokers, and 38% were heavy alcohol users at the time of surgery. Most tumors were mucosal squamous cell carcinomas (75%), and most defects were of the oral cavity, including maxillary defects (66%). Because a subset of patients had surgery during a period where patients were routinely admitted to the ICU post- operatively, 28% of patients required a postoperative ICU stay. However, after the change in protocol to admit patients direct to a specialty-specific floor, less than 10% of patients required an ICU stay. Comorbidity Status The comorbidity status for the cohort is presented in Table 2 . In addition to the age-adjusted CCI (mean [SD], 5.0 [2.3]), specific types of comorbidities are reported as these may be related to specific types of complications. There was a high rate of past/current smoking (78.0%), COPD (50.3%), and alcoholism at the time of surgery (37.7%). A history of hypothyroidism was noted in 13.4% of patients at the time of surgery. Outcome Summary Primary and secondary complication outcomes are presented in Table 3 : any complication (54.0%), wound-healing com- plications (15.0%), and wound infection complications (11.7%). Partial or total flap loss occurred in 18 patients (3.5%), MI in 8 (1.6%), cerebrovascular event in 4 (0.8%), pneumonia (7.4%), DTs in 33 (6.4%), and C difficile colitis in 7 (1.4%). Our inpatient mortality rate was 1.6%. Predictors of Any Complication The univariable and multivariable logistic regression predic- tors of any complication are presented in Table 4 . Multivariable analysis demonstrated that length of OR time ( P \ .01), CCI ( P \ .01), and tumor site (oral cavity and

Table 1. Patient Demographics and Clinical Characteristics (n = 515). a

Characteristic

Value

60.1 6 12.8 174 (33.8) 145 (28.2) 455 (93.8) 113 (21.9) 200 (38.8) 202 (39.2) 194 (37.7) 110 (21.4) 275 (53.4) 130 (25.2) 333 (65.6) 101 (19.6) 76 (14.8) 170 (33.0)

Age, y Female

Preoperative RT/CCRT Preoperative OPAC

Smoking history Never

Yes—past

Yes—current

Alcoholism at time of operation

Tumor pathology Mucosal squamous cell carcinoma (T1-T2) Mucosal squamous cell carcinoma (T3-T4) Defect subsite Oral cavity (including maxillary defects) Larynx, hypopharynx, oropharynx Other: skin, parotid, skull base, neck Other

Bone containing flap Intraoperative factors Ischemia time, min b

139.1 6 39.9 544.5 6 130.2

Operative time, min

Operative time (8 hours or less)

173 (33.7)

457.5 6 394.0

Estimated blood loss, mL

Estimated blood loss (500 mL or less)

380 (73.9)

5508.4 6 1962.8 485.1 6 543.7

Crystalloid, mL

Colloid, mL

Blood transfusion c Fresh-frozen plasma c

160 (31.1)

9 (1.8)

Postoperative intensive care unit

146 (28.4)

Abbreviations: OPAC, preoperative assessment clinic; RT/CCRT, radiother- apy/concurrent chemoradiotherapy. a Categorical variables presented as n (%) and continuous variables as mean 6 SD. b n = 320. c Intraoperative or postanesthethic care unit (PACU).

larynx/hypopharynx/oropharynx; P \ .01) were all signifi- cant predictors of developing any complication. We performed a conversion of OR time from minutes to hours to allow for easier interpretation of the results. For each hour increase in OR time, odds of any complica- tion increased multiplicatively by 1.21 (95% confidence interval [CI], 1.11-1.32). For each unit increase in CCI, odds of any complications increased multiplicatively by 1.21 (95% CI, 1.11-1.32). Those with sites classified as oral cavity (including maxilla) and larynx/hypopharynx/ oropharynx had greater odds of any complication com- pared to those with nonmucosal subsites with an odds ratio of 3.12 (95% CI, 1.76-5.52) and 4.54 (95% CI, 2.31- 8.91), respectively.

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