Fried et al studied factors affecting the conversion of patients from a laparascopic cholecystectomy to an open procedure. Identification of patients who have a significant chance of being converted can help in surgical planning, especially for outpatient procedures. The authors are from McGill University in Quebec.
Parameters associated with increased risk for conversion to an open procedure:
(1) acute cholecystitis
(2) age >= 65 years
(3) obesity
(4) male gender
(5) thickened gallbladder wall on ultrasound
|
Parameter |
Odds Ratio |
95% Confidence Interval |
|---|---|---|
|
acute cholecystitis |
5.79 |
3.21 – 10.43 |
|
age >= 65 years |
2.00 |
1.15 – 3.49 |
|
obesity |
1.77 |
1.02 – 3.05 |
|
male gender |
2.54 |
1.48 – 4.37 |
|
thickened gallbladder wall |
1.72 |
0.93 – 3.20 |
from Table IV, page 37
Method 1: Age as a Continuous Variable:
|
Parameter |
Finding |
Points |
|---|---|---|
|
cholecystitis |
subacute or chronic |
0 |
|
|
acute |
1 |
|
body weight |
not obese |
0 |
|
|
obese |
1 |
|
gender |
female |
0 |
|
|
male |
1 |
|
gallbladder wall |
not thickened |
0 |
|
|
thickened |
1 |
probability of conversion =
= EXP(X) / (1 + EXP(X))
X = (0.0248 * (age in years)) + (0.8925 * (points for sex)) + (1.7764 * (points for acute disease)) + (0.5589 * (points for obesity)) + (0.5294 * (points for thickened wall)) – 5.7924
Method 2: Age as a Dichotomous Variable
|
age >= 65 |
acute? |
sex |
obese? |
thickened? |
Percent Convert |
|---|---|---|---|---|---|
|
N |
N |
F |
N |
N |
0.9% |
|
N |
N |
F |
N |
Y |
1.6% |
|
N |
N |
F |
Y |
N |
1.6% |
|
N |
N |
F |
Y |
Y |
2.7% |
|
N |
N |
M |
N |
N |
2.3% |
|
N |
N |
M |
N |
Y |
3.9% |
|
N |
N |
M |
Y |
N |
4.0% |
|
N |
N |
M |
Y |
Y |
6.7% |
|
N |
Y |
F |
N |
N |
5.1% |
|
N |
Y |
F |
N |
Y |
8.4% |
|
N |
Y |
F |
Y |
N |
8.6% |
|
N |
Y |
F |
Y |
Y |
14.0% |
|
N |
Y |
M |
N |
N |
12.0% |
|
N |
Y |
M |
N |
Y |
19.0% |
|
N |
Y |
M |
Y |
N |
19.4% |
|
N |
Y |
M |
Y |
Y |
29.2% |
|
Y |
N |
F |
N |
N |
1.8% |
|
Y |
N |
F |
N |
Y |
3.1% |
|
Y |
N |
F |
Y |
N |
3.2% |
|
Y |
N |
F |
Y |
Y |
5.3% |
|
Y |
N |
M |
N |
N |
4.5% |
|
Y |
N |
M |
N |
Y |
7.5% |
|
Y |
N |
M |
Y |
N |
7.7% |
|
Y |
N |
M |
Y |
Y |
12.5% |
|
Y |
Y |
F |
N |
N |
9.7% |
|
Y |
Y |
F |
N |
Y |
15.6% |
|
Y |
Y |
F |
Y |
N |
15.9% |
|
Y |
Y |
F |
Y |
Y |
24.8% |
|
Y |
Y |
M |
N |
N |
21.4% |
|
Y |
Y |
M |
N |
Y |
31.9% |
|
Y |
Y |
M |
Y |
N |
32.5% |
|
Y |
Y |
M |
Y |
Y |
45.3% |
from Table III, page 37
Specialty: Gastroenterology, Surgery, general
ICD-10: ,
