2017 Sec 1 Green Book

Flores et al. / Journal of Cranio-Maxillo-Facial Surgery 43 (2015) 1614 e 1619

congenital anomaly (25.93%); and pre-operatively intubated (7.41%).

was performed for the outcome variable denoting failures due to all causes ( Fig. 1 ).

4. Discussion

3.2. Bivariate and regression analysis of variables associated with failure

There have been multiple publications demonstrating the effectiveness of MDO in relieving airway obstruction in patients affected by severe airway stenosis secondary to Robin sequence ( Denny et al., 2001; Denny and Kalantarian, 2002; Denny, 2004 ). As a result MDO is increasingly used as a fi rst line intervention for the surgical treatment of MDO. Unfortunately, standardized protocols of assessment and intervention have not yet been formulated to treat this challenging patient population. To construct these stan- dardized care plans, a consistent means of assessing surgical out- comes needs to be de fi ned. The current literature demonstrates varying de fi nitions of ‘ failure ’ of MDO including: the clinical pres- ence of apnea; an objective drop in AHI; the need for tracheostomy, redistraction, or other airway procedures; and death ( Dauria and Marsh, 2008; Paes et al., 2013; Papoff et al., 2013; Flores et al., 2014; Lam et al., 2014; Tahiri et al., 2014 ). Agreement on the de fi - nition of failure is critical to assessing differing patient variables associated with successful and unsuccessful distraction and is ul- timately required to create de fi nitive treatment protocols. In this study it is shown that differing de fi nitions of successful distraction not only have an effect on the success rate of distraction but also implicate differing sets of patient variables associated with unsuccessful distraction ( Table 2 ). An almost equal number of pa- tients were characterized as failures by need for tracheostomy ( n ¼ 7) and inadequate improvement of AHI ( n ¼ 6). Furthermore, an additional patient died from apnea-related disease. Commonly, the success rate is de fi ned as avoidance of tracheostomy; if this measure is used, only 50% of patients with a problem would be identi fi ed. The variables associated with failure of distraction are also affected by the de fi nitions of failure. This can most clearly be seen in Table 2 . The table provides an easily visualized data represen- tation of important variables of failure across differing de fi nitions. When failure is de fi ned by avoidance of tracheostomy, the previ- ously described standard variables appear as important: CNS

Failure was de fi ned as follows, with parenthesized numbers indicating the number of patients within that group: need for tra- cheostomy (7), death due to apneic disease (1), AHI > 20 after distraction (6), failure due to tracheostomy or insuf fi cient reduction in AHI (12), any of these failures (13), and all failures as well as all- cause mortality (16). These failures were then analyzed in a bivar- iate fashion to reveal variables that were speci fi cally associated with each cluster of failure variables. Table 2 outlines all variables in this analysis. Values in bold indicate variables signi fi cantly associ- ated with failure. In this analysis of speci fi c causes of failure, certain variables were important across all types of failure. These include G ER, A ge > 30 days, N eurologic anomaly, airway anomalies O ther than lar- yngomalacia, I ntact palate, and pre-operative in T ubation. Paired t - test analysis for numeric variables demonstrated an age of approximately 30 days as being signi fi cant in failure by tracheos- tomy, AHI, and any failure ( Table 3 ). Interestingly, there was a trend towards failure in children below 2.5 kg birth weight, but this only reached signi fi cance in the failure by tracheostomy or AHI > 20 group. Elucidation of variables associated with failure provided the material with which to create a scoring system for the prediction of failure of MDO. The variables assessed were G ER, A ge > 30 days, N eurologic anomaly, airway anomalies O ther than laryngomalacia, I ntact palate, and pre-operative in T ubation. Scores were created for every variation possible for these variables. A sample of the analysis is demonstrated in Table 4 . The top eight scores by ROC curve analysis were listed for each mode of failure. ROC curve analysis Table 2 Bivariate analysis of pre-operative demographic variables against all causes of failure. % ( p value) Failure by tracheostomy 3.3. Construction of a tool to predict failure in the MDO population

Failure by AHI

Any failure

Any failure þ deceased

Total Male

8.64%

8.11% 9.3 (1) 6.45 (1) 5.26 (1)

16.67%

19.75%

12.77 (0.229) 2.94 (0.229) 16.67 (0.187) 4.17 (0.668) 20 (0.059) 0 (0.335) 22.22 (0.04)

21.74 (0.219) 9.38 (0.219) 23.81 (0.32) 31.58 (0.073) 5.88 (0.277) 29.41 (0.143) 18.18 (1)

23.4 (0.405) 14.71 (0.405) 33.33 (0.066) 25 (0.543) 30 (0.206) 5.88 (0.171) 38.89 (0.039) 50 (0.358) 8.33 (0.443) 23.81 (0.751) 29.41 (0.09) 25.45 (0.077) 28.57 (0.158) 28.57 (0.339) 20 (1) 50 (0.011)

Female

LBW IUGR

14.29 (0.343) 11.76 (0.616)

Premature Isolated RS

5.88 (1)

CNS anomaly

13.33 (0.595)

Cardiac anomaly

10 (1)

5.26 (1)

15 (1)

GI anomaly GU anomaly

50 (0.166)

0 (1)

50 (0.307) 9.09 (0.68) 15.79 (1)

8.33 (1)

0 (0.588) 5.88 (1)

Other anomalies

4.76 (0.67)

17.65 (0.038)

28.13 (0.032) 54.55 (0.002) 23.08 (0.05) 28.57 (0.055)

GER

13.79 (0.202) 22.22 (0.153) 12.24 (0.091) 11.54 (0.659) 10 (0.659) 4.76 (0.668) 16.67 (0.249) 12.50 (0.38)

41.67 ( < 0.0001)

NISSEN

Gastrostomy

12.73 (0.09) 17.86 (0.045) 19.05 (0.07)

Other airway anomalies

Laryngomalacia Syndromic Intact palate Age > 30 days

28.57 (0.1) 16.67 (1)

8 (1)

20 (1)

30.77 (0.012) 19.23 (0.031)

41.67 (0.024) 26.92 (0.11)

38.46 (0.122) 34.62 (0.034)

Intubated 66.67 (0.012) AHI: apnea-hypopnea index; CNS: central nervous system; GER: gastroesophageal re fl ux; GI: gastrointestinal; GU: genitourinary; IUGR: intrauterine growth restriction; LBW: low birth weight; RS: Robin sequence. Signi fi cant values ( p < 0.05) are listed in bold. 50 (0.007) 50 (0.15) 80 (0.002)

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