Preoperative factors predicting conversion from laparoscopic to open cholecystectomy

Preoperative factors  predicting conversion from laparoscopic to open cholecystectomy

Mohammad A Gad,MD; Mohamed E Shams,MD; Gouda M Ellabban,MD

Department of Surgery, Suez Canal University, Ismailia, Egypt.

Abstract

Background: Laparoscopic cholecystectomy (LC) has replaced open cholecystectomy (OC) for the treatment of gallbladder disease. However, certain cases still require conversion to open procedures. Conversion to OC can be predicted based on parameters available preoperatively. This study identified risk factors that may predict conversion from a laparoscopic to an open procedure.

Patients and methods: From January 2007 to January 2010, a total of 130 laparoscopic cholecystectomies performed in our list were included in this prospective clinical study at Suez Canal University Hospitals. Patients were mostly females (71.5%) and age ranged from 23ys-

69ys with symptomatic GB stone disease. Analysis of many predictive parameters including; history,  laboratory  data, ultrasound  results,  and intraoperative details  were performed. Multivariate logistic regression was used to determine those variables predicting conversion of LC to open OC during the procedure.

Results: Laparoscopic cholecystectomy was converted into OC in 12.3% of the patients.The cause of conversion in this group was uncontrollable bleeding from injured cystic artery during difficult dissection in (37.5%), marked adhesions due to previous upper abdominal surgery (31.3%), inflamed thick GB wall (18.7%) and marked obesity (12.5%). Preoperative factors that can predict conversion from laparoscopic to OC are (in descending sort) elevated total leucocytic count (TLC) andfever(acute inflammation), pericholecysticfluid collection by US, elevated bilirubin, BMI > 35 Kgfm2, thickened GB wall, US positive Murphy's sign , previous upper abdominal surgery, low albumin, age >60years and ascites.

Conclusion: In feverish morbidly obese patients with elevated TLC, thickened GB wall and/or pericholecystic fluid collection on US assessment with or without previous upper abdominal surgery, or low plasma albumin or mild jaundice (patients with one or more predictive factors), these patients should be subjected to LC by highly expert skillful team or may be the option of open   cholecystectomy  is   the   preferable  from   the   start  to   lessen  morbidity.

Key words: Laparoscopic cholecystectomy; predictive factors; conversion.

Introduction:

Gallbladder disease is the most common of

all digestive disorders requiring hospitalization, and cholecystectomy is the most common elective abdominal operation undertaken.l Today, cholecystectomy is the safest, the most effective and widely recommended treatment for gallstone disease. Since the introduction of laparoscopic cholecystectomy into general practice in 1990, it has rapidly become the gold standard for symptomatic cholelithiasis, while open cholecystectomy is now reserved

for   difficult  and   problematic  cases.2

Laparoscopic cholecystectomy decreases postoperative pain, allows earlier oral intake, shortens hospital stay, enhances earlier return to normal activity and improves cosmoses over open cholecystectomy.3 Day after day it has been considered for the management of more complicated gallbladder diseases.4  With increasing laparoscopic experience, there are few contraindications to laparoscopic cholecystectomy for symptomatic cholelithiasis. However, approximately 2% to

15% ofpatients require  conversion to open cholecystectomy  for   various reasons.5

Accurate prediction of the risk of conversion is of great interest to the clinician as patients with a high risk of conversion could be operated on either by or under the supervision of a more experienced surgeon. When  there  is high predicted  risk of conversion,  this may allow the surgeon to take an early decision to convert to open cholecystectomy when difficulty is encountered during dissection; this may shorten the  duration of  surgery and  decrease the associated morbidity.4-6 The aim of the current study was to evaluate the preoperative factors (clinical, laboratory and  ultrasonographic) predicting conversion from  laparoscopic cholecystectomy to open cholecystectomy.

Patients and methods:

This prospective clinical trial included  a total of 130 patients; mostly females (71.5%) and  age  ranged from 23ys-69ys with symptomatic GB  stone  disease who  were admitted to our list and surgery department along 3 years duration  (from January  2007- January  201 0).   Other  number  of cholecystectomies in the  same  period  was excluded because it underwent OC from the start (acutely inflamed or technical problems). Patients were evaluated via clinical, laboratory and US assessment. All the patients  of our study underwent  either LC or OC. Rate and causes  of  conversion were estimated.

Results:

In this study, the mean age of our patients was 45.9 years. More than two thirds ofthe patients were females (71.5%). Less than half

ofthe patients were from rural areas (41.5%). It was found that 20% of the studied patients were smokers.

The most common clinical presentation was

right hypochondrial pain and/or epigastric pain (73.8%). Nausea with or without vomiting was evident  among  36.2%. Fatty dyspepsia was present among more than two thirds of the patients (68.5%). The  least common presentations were fever (14.6%) and history of jaundice (13.1%). Temperature was more than 37.5°C in 19 patients. Murphy's sign was evident among 22.3% of the patients and ascites was clinically present in 10.8% of the studied patients.

Total bilirubin was sub-clinically elevated orting of jaundice in 16.1% of the cases while TLC was elevated  in 21.5%  of the patients. Liver enzymes were elevated in 18.5% of the patients while plasma albumin was reduced in

13.1%.

The  most  common US finding  was  the thickened GB wall (28.5%). Ultrasonographic Murphy's  sign was elicited among 23.8% of the studied patients. The GB was visualized to be distended in 17.7% of the studied patients and pericholecystic fluid collection was evident in 14.6% of the cases.

Laparoscopic cholecystectomy was converted  to OC in 16 patients (12.3%). The cause  of conversion in the largest  group of these cases was uncontrollable bleeding from injured cystic artery (37.5%) during dissection. Noticeable adhesions due to previous upper abdominal operations were the cause of conversion in 31.3% of this group while marked obesity was the cause of conversion in 12.5% of the converted patients.

Table (1):Comparison of surgery duration and hospital stay among converted and laparoscopic patients (n=130).

P-value 0.001

There was statistically significant difference between patients who were converted to OC as regarding; age, BMI, previous  upper abdominal operation, fever, elevated TLC, mild elevated bilirubin, +US Murphy's sign,

thickened GB wall and pericholecystic oedema. Sex,  smoking habit, elevated alkaline phosphatase and liver  enzymes and US diagnosed ascites didn't show any statistically significant difference Table(2).

Table (1): Comparison between laparoscopic cases and converted cases among the studied patients.

*Statistically significant at 0.05 level.

**Statistically significant at O.Ollevel.

NS: NO statistically significant difference (p-value > 0.05).

Multivariate analysis of preoperative patient's factors that independently predict conversion from LC to OC showed that 28.6% of the morbid obese patients (2 out ?cases) have been subjected to conversion (OR: 3.1, CI: 0.6 - 17.8) and 16.7% of the patients older than 60 years old have been converted (OR:

1.5 CI:0.3 - 5.9) .

Multivariate analysis of preoperative symptoms and signs that independently predict

conversion showed that 31.6% of the patients with fever have been converted to OC (OR:

4.7, CI:1.5- 15.09) and 31.3% ofthe patients

with history of previous upper abdominal surgery have been subjected to conversion (OR: 2.55, CI: 1.21 - 15.41) while 14.3% of the patients with ascites (clinically) have been converted (OR:1.2,CI: 0.2- 6.1).

Multivariate analysis of  preoperative laboratory findings that were  independently

predictive of  conversion from  LC  to  OC showed that 28.6% of the patients with elevated TLC have been converted from laparoscopic to OC (OR: 4.8, CI: 1.6- 14.2), 28.6% ofthe patients having mild elevated total bilirubin

have been converted to OC (OR: 4, CI: 1.3 -

12.6)  and  17.6%  of  the  patients with  low albumin  have been subjected to conversion (OR: 1.6, CI: 0.4 - 6.6).

Table(3): Multivariate analysis of preoperative ultrasonographic factors that independently predict conversion from LC to OC.

*Statistically significant (p-value < 0.05).             CI: confidence interval.

Table (4):Multivariate analysis of preoperative factors that independently predict conversion.

*Statistically significant (p-value < 0.05).         CI: confidence interval.

Discussion:

The current study was conducted to evaluate the preoperative factors (clinical, laboratory and ultrasonographic) predicting  conversion from LC to OC. In our study the overall conversion rate from LC to OC was estimated to be 12.3%. In previous studies, conversions to OC were 8.1% and 5.3%.7,8 This estimated rate of conversion is less compared to our rate (12.3%) and may be due to the large series in these studies.Similarly; Lo et al.,9 demonstrated a  conversion rate  of  II% that  is  nearly consistent with  our  findings. However, approximately 2% to 15% of patients require conversion to open  surgery for  various reasons.5,6 Conversion to OC is occasionally necessary to avoid or repair injury, delineate confusing anatomic relationships, or  treat associated conditions. Conversion to OC has been  associated with  increased overall morbidity, surgical site  and  pulmonary infections, and longer hospital stayslO and this finding came in agreement  with our data as the mean operative time and duration ofhospital stay  were  significantly prolonged with conversion.

The  ability to  accurately identify an individual patient's risk for conversion based on preoperative information can result in more meaningful and accurate preoperative counseling. Stratification of risk for technical difficulty, may  improve patient  safety  by minimizing  time to conversion, and helps to identify patients in whom  a planned open cholecystectomy  is indicated.ll,12

Recent results demonstrated that conversion to OC can be predicted based on parameters available preoperatively)Accordingly we have found that body temperature more than 37.5°C was associated with conversion rate 31.6% (6 out of 19 cases).

Inthis study the first (commonest) cause of conversion was uncontrollable bleeding from injured cystic artery during dissection in difficult situations (37.5%). Marked adhesions that make visualization via laparoscope very difficult was the second  common  cause  of conversion in  31.3%  of  the  patients with previous upper abdominal surgery. The thickened GB wall with pericholecystic oedema with unclear anatomy and difficult dissection

was the cause of conversion  in 18.7% of the cases. Among 12.5% of the patients, marked obesity  was the cause  of conversion in the converted group (totall6 patients).Conversion was significantly higher in our patients with fever> 37.5°C, elevated WBC, mild elevated bilirubin and low albumin. Kanaan and co­ workers13 found that patients having open conversion were significantly older, had greater prevalence of cardiovascular disease and were more  likely to be males. This  is not  in agreement with our results.Conversion in acute cholecystitis patients  was associated with a greater leukocyte count; in gangrenous cholecystitis patients, 29%  had  open conversion.13

Among different ultrasonographic findings, thickened gall bladder wall, pericholecystic fluid collection and positive US Murphy's sign were  significantly more  prevalent with converted patients. Sex, smoking habit, elevated alkaline phosphatase and liver enzymes didn't show any statistically significant  difference. Rosen et al.,8 retrospectively evaluated 34 parameters including patient demographics, clinical history, laboratory data and ultrasound results among a total of 1347 laparoscopic cholecystectomies performed at the Cleveland Clinic Foundation (CCF) to assess preoperative factors predicting conversion from LC to OC. Multivariate analysis revealed that for all cases, a white blood cell count> 9 (2.9 greater odds ratio  [OR] of conversion P = 0.006) and a gallbladder wall thickness >0.4 em (7.2 OR, P <0.001) predicted conversion to OC. These results are in agreement with our findings, in addition, obese patients with acute cholecystitis undergoing  LC have an increased chance of conversion like our results.8

Multivariate analysis of the preoperative factors that can predict conversion  from LC to OC showed that elevated WBC, fever, peri­ cholecystic fluid collection, thickened GB wall and positive Murphy's sign, elevated bilirubin, BMI > 35 Kglm2, previous upper abdominal surgery, low plasma albumin, older age > 60 years old, and ascites are significant factors that can independently predict conversion from LCtoOC.

Other  researchers examined risk factors

predicting  conversion  in   an   elective

cholecystectomy. These authors found that in elective LC for elderly patients  (65 years or older), males, and patients with multiple attacks (more than 10) ofbiliary colic, or a documented history of acute cholecystitis were more likely to require conversion.14

In similar study performed the conversion group  had  significantly more  elderly  (-65 years) patients (66% vs. 37%; P = 0.02) and larger gallstones as shown on US (25 mm vs.

15.5 mm; P = 0.03). Other preoperative factors associated with severe inflammation were not predictive. They  concluded  that conversion from LC to OC for acute cholecystitis is at risk for postoperative complications. In elderly patients with  large  gallstones, the surgeon should make an early decision to convert if severe adhesions  are   encountered.9,15

Consistent with our  results,  Liu et ai.,l5 found that age more than 65 years, obesity, interval elective  LC for acute cholecystitis, and a thickened gallbladder wall  predicted conversion. Some  authors noted  a higher incidence of conversion in male patients.5,6,16,17

This  finding wasn't  obvious in our  study.

Another  multivariate analysis  identified male gender, elevated white blood cell count, low  serum  albumin, ultrasound finding of pericholecystic fluid, and elevated total bilirubin as independent predictors of conversion.7 This is consistent with our findings but for that we have identified  gender not to be a predictive factor.

In previous studies,  it was estimated  that conversion prolongs postoperative hospital stay as long as 9.7 days,lS-20 We have also realized that conversion significantly prolongs the duration of hospital stay. These results are also consistent  with what has been reported by other investigators.21

In conclusion we can state that older age patients age > 60 years old or morbidly obese with fever, elevated TLC, thickened GB wall and/pericholecystic fluid  collection on US assessment or low plasma albumin should be subjected  to open cholecystectomy from the start or be done by laparoscopy under supervision of highly  expert  team with the option of conversion in mind to avoid unneeded post-operative complications.

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