Sometimes it is necessary to convert to an open cholecystectomy after starting with a laparoscopic procedure. Alponat et al identified certain factors which were associated with an increased need for the change in the operative procedure. The authors are from the National University Hospital in Singapore.
Parameters identified by multiple logistic regression:
(1) acute cholecystitis
(2) thickened gallbladder wall on ultrasound
(3) increased white blood cell count
(4) increased alkaline phosphatase
|
Parameter |
Odds Ratio |
95% Confidence Interval |
|
acute cholecystitis |
3.12 |
1.46 – 6.68 |
|
thickened gallbladder wall |
3.75 |
1.83 – 7.68 |
|
increased WBC count |
3.68 |
1.76 – 7.75 |
|
increased alkaline phosphatase |
2.23 |
1.14 – 4.36 |
from, Table 3, page 631
|
Parameter |
Finding |
Points |
|
acute cholecystitis |
absent |
0 |
|
|
present |
1.1390 |
|
gallbladder wall on ultrasound |
< 3.5 mm |
0 |
|
|
>= 3.5 mm |
1.3227 |
|
WBC count |
<= 11,000 per µL |
0 |
|
|
> 11,000 per µL |
1.3063 |
|
alkaline phosphatase |
normal |
0 |
|
|
elevated |
0.8014 |
where:
• Each point assignment for a parameter present is the LN(odds ratio).
• Liver function tests were classified as normal or abnormal. Since there are several different methods for measuring alkaline phosphatase activity and since reference ranges may vary between facilities, no global reference value is given for the alkaline phosphatase.
X =
= (-4.2149) + SUM(points for all 4 parameters)
probability of conversion to an open cholecystectomy =
= 1 / (1 + EXP((-1) * (X)))
where:
• Some of the probabilities for different combinations of the parameters are given on page 631, bottom of the second column).
• If none of the risk factors are present, the conversion rate was 1.5%
• If all 4 risk factors are present, the conversion rate was 58.7%.
Specialty: Gastroenterology, Surgery, general
ICD-10: ,
