The Reasons and Risk Factors for Conversion to Open in Laparoscopic Cholecystectomy

Original article
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The Reasons and Risk Factors for Conversion to Open in Laparoscopic Cholecystectomy (indirmek için tıklayınız)
Mehmet KAPLAN 1, Bülent SALMAN 2, Halil İbrahim İYİKÖŞKER 1, Hüseyin Cahit YALÇIN 1,
Utku YILMAZ 2

1 Department of General Surgery, Gaziantep Av.Cengiz Gökçek State Hospital, GAZİANTEP
2 Department of General Surgery, Gazi University, School of Medicine, ANKARA


ABSTRACT

The aim of this study was to investigate the reasons for conversion to open surgery and to evaluate the possible risk factors for conversion in patients who were assigned to laparoscopic cholecystectomy.
Between September 2004 and December 2006, laparoscopic cholecystectomy was attempted in 300 well-documented patients. Patients who had to be converted were compared with laparoscopically completed cases with regard to demographics, current severity of cholecystitis (acute, chronic, subacute), previous acute attacks, previous abdominal surgery, concurrent intraabdominal diseases, surgical findings, and complications.
Twenty-three patients (7.7%) were converted to open surgery. The reasons for conversion were; inability to proceed with laparoscopic dissection in 11 cases (47.8%), concurrent findings requiring open surgery in 4 (17.4%), bleeding in 3 (13%), bile duct injury in 2 (8.7%), spillage of multiple stones in 1 (4.35%), colonic perforation in 1, and gallbladder malignancy in 1 case. Conversion to open surgery was found to be significantly correlated with existence of upper abdominal incisions (OR=28.9), existence of previous acute attacks treated conservatively (OR=14.9), misdiagnosed subacute cholecystitis with inflammatory adhesions (OR=9.8), male gender (OR=5.2).
Patient characteristics, such as male gender, existence of upper abdominal incisions, or history of acute attacks, indicate a higher possibility of conversion from laparoscopic to open cholecystectomy.

Key Words: Laparoscopic cholecystectomy, conversion to open surgery, risk factors



INTRODUCTION
Since 1985, laparoscopic cholecystectomy (LC) has developed rapidly and become the gold standard treatment of various gallbladder diseases1. Contrary to the early reports of increased complication rates, recent studies suggest that LC can be performed with lower morbidity and mortality, compared with the traditional open surgery (OS)2,3. Its benefits over open cholecystectomy include less patient discomfort, better cosmetic results, shorter hospitalization, and more rapid return to full activities postoperatively4-6. Nevertheless, conversion to OS may occasionally be obligatory for patients in whom LC cannot be performed safely, and/or because of technical difficulties or intra-operative complications7-10. The most common reported reasons for conversion have been inability to perform a safe dissection due to obscure anatomy, inflammation, or adhesions, bleeding, and bile duct injuries8,9. Other infrequent factors to result in conversion include unexpected malignancies, inability to create pneumoperitoneum, instrument failure, multiple tears in the gallbladder, and common bile duct stones10-12.
Conversion from LC to OS should not be considered as a failure or a complication of laparoscopic operation; rather, it should be accepted as a step towards a safer surgery when completion of LC is not be possible13. Nevertheless, surgeons are generally reluctant to convert the procedure to OS because of the more time consumed, increased surgical costs and expectations of patient. Therefore, preoperative estimation of the risk probability for requirement of conversion to open surgery is important, and it may allow some advantages both for the surgeon and candidates of LC. In this way, the surgeon can discuss with the patients the likelihood of conversion to open surgery more accurately, and the patient will have adequate emotional preparation. Furthermore, more efficient arrangement and realistic planning of the operating schedule can be done, and the necessity of a consultant laparoscopic surgeon can be considered. The last significance of the awareness of the risk factors preoperatively is that, if preventable, the reasons of the conversion would be eliminated or, if not, then the decision of exclusion of more challenging cases would be possible, especially in the training situations.
The aim of this study was to investigate the reasons for conversion to OS and to evaluate the possible risk factors for conversion in patients who were assigned to LC.

PATIENTS AND METHODS

From September 2004 to December 2006, 312 patients underwent cholecystectomy, and LC was attempted in 300 of them (93.6%). There were 12 patients selected directly for open surgery due to various causes, such as severe heart and/or pulmonary diseases, suspicion of malignancy, concomitant disease requiring OS, or multiple previous upper abdominal incisions, and excluded from the analysis. Patients with a single upper abdominal incision were assigned for LC. The demographics and reasons of the selection for open surgery of these patients are shown in Table 1. Of the 300 patients in whom LC was attempted, there were 68 male (22.7%) and 232 female patients (77.3%), with a mean age of 52.6 years (range 19 to 81 years). All of the operations were carried out or assisted by the same four consultants with a high level of laparoscopic experience. We developed a detailed database and recorded the data included demographics such as age, sex and obesity, current severity of cholecystitis (acute, chronic, subacute), history of previous acute attacks, jaundice and pancreatitis, abnormal preoperative liver function tests, preoperative radiologic findings, previous abdominal surgery, concurrent intra-abdominal diseases, surgical findings, and complications. Obesity was defined as body mass index above the cut off value of 28 (kg/m2). Cholecystitis was diagnosed by clinical and laboratory assessments and pathological evaluation. All patients had routine basic preoperative tests, including liver function tests (serum alanin transaminase, aspartate transaminase, alkaline phosphatase, gamma glutamyl transpeptidase, and bilirubin) and abdominal ultrasonography, and follow-up evaluation six weeks postoperatively. In 12 patients who had clinical, radiologic and/or biochemical evidence of common bile duct stones, selective preoperative ERCP was performed. Endoscopic sphincterotomy and complete stone removal was achieved in 10 patients, who were confirmed to have common bile duct stones. Open trocar insertion was attempted in all patients with previous abdominal surgery because of the probability of intra-abdominal adhesions. All patients who presented with acute cholecystitis in the first 72 hours underwent emergency LC. The patients whose the pathological results did not support the clinical and laboratory data were not considered to have acute cholecystitis. If the patients with acute infection were admitted more than 72 hours after the onset of symptoms, elective LC was carried out 8-10 weeks later following a course of conservative treatment (delayed cholecystectomy). The operations were performed with the standard four-port technique.
The statistical analysis was carried out by means of Fisher’s chi-squared test to determine the p values for unvaried analysis in order to determine each significant risk factor for conversion. The odds ratios (OR) were calculated with their 95% confidence intervals. The variables with numerical values were analyzed with Mann-Whitney U test to compare the groups.

RESULTS

Of the 300 patients in whom LC was attempted, 23 (7.7%) required conversion to OS (Table I). In spite of the female predominance in this series, the rate of conversion was found to be significantly higher in males (p<0 .001="">0.05). When the type of previous abdominal surgery was considered, it was observed that, in contrast to previous lower abdominal surgery, completion of laparoscopic surgery was significantly affected by previous upper abdominal surgery (p<0 .001="">0.05).
Table II. Rate of conversion of LC to OS according to patient characteristics


Patient Group

No.
of Patients

No. (%)
of completed

No. (%)
of conversions

p*
Overall
300
277 (92.3%)
23 (7.7%)

Sex
M
F

68
232

55 (80.9%)
222 (95.7%)

13 (19.1%)
10 (4.3%)

<0 .001="">60
<60>28)

165
135

150 (90.9%)
127 (94.1%)

15(9.1%)
8 (5.9%)

>0.05
Previous upper abdominal surgery
Yes
No

6
294

2 (33%)
275 (93.5%)

4 (66.7%)
19 (6.5%)

<0 .001="">0.05
History of acute cholecystitis
Yes
No

27
273

16 (59.3%)
261 (95.6%)

11 (40.7%)
12 (4.4%)

<0 .001="">0.05

Pericholecystitis
Yes
No

26
274

17 (65.5%)
260 (94.9%)

9 (34.6%)
14 (5.1%)

<0 .001="">60
<60>60 years

p *
Concomitant disease
Yes
No

74 (67.3%)
159 (83.7%)

36 (32.7%)
31 (16.3%)

=0.001
Previous abdominal surgery
Yes
No

19 (46.3%)
214 (82.6%)

22 (53.7%)
45 (17.4%)

<0 .001="">0.05
Hospitalization a
1.27±0.61
1.5±0.80
<0 .05="">0.05

* Fisher's exact or Mann-Whitney U test, where appropriate
a The values were given as mean ± standard deviation

The reasons for conversion to OS, other than the above mentioned, were inability to define anatomy in 11 patients (47.8%) and gallbladder malignancy in one (Table IV). This was the most frequent cause of conversion due to edema, dense adhesions between thickened gallbladder with foreshortening of the cystic duct and neighboring tissues, and chronic inflammation.
The rate of conversion to OS was found to be significantly correlated with existence of upper abdominal incisions (OR=28.9), previous acute attacks treated conservatively (OR=14.9), misdiagnosed subacute cholecystitis with inflammatory adhesions (OR=9.8), and male gender (OR=5.2). Furthermore when a cut-off value of 60 years was considered, the risk of conversion of the patients aged >60 were found to be significantly higher (p<0 .05="" or="3.6)">60 years according to the multiple variables (Table VI). Among them, significantly more frequent previous abdominal surgery, intra-abdominal adhesions, pericholecystitis, concomitant diseases, drain usage (p<0 .001="">60 years than the younger, indicating more problematic patients for LC.

DISCUSSION

In the setting of acute cholecystitis (AC), the presence of pericholecystic adhesions, tissue edema, and inflammation that obscure the anatomy can cause difficulty in dissection and also perforation of distended and fragile gallbladder during traction may occur. In these circumstances the increased conversion and complication rates are expected. In this study, interestingly AC was not found to be a risk factor for conversion to open surgery in contrast to numerous studies7,14-17. Kum CK et al17. have investigated the reasons of conversion in the setting of AC. They concluded that because AC accounted approximately 20% of pathologies requiring cholecystectomy, in the series with AC fewer than 10% of the total cases of LCs, the lower reported rates of conversion to OS might have been due to the selection of some cases of AC directly to open surgery and exclusion from the analysis. In this study, the conversion rate of 33 cases with AC did not statistically differ from the cases without AC (%9.1 vs. %7.5, p>0.05). This may be partly related to the exclusion from the study of 5 out of 38 patients with acute cholecystitis, selected directly to open surgery initially.
Even before laparoscopic surgery, managing AC was controversial, some advocating medical treatment and delayed surgery and others preferred early surgery18. Our policy is to perform emergency LC for patients with AC admitted in the first 72 hours from the beginning of the symptoms or in the case of failed initial conservative treatment. The patients with the symptoms of AC longer than 72 hours are treated with conservative regimen and scheduled for delayed surgery after 6-8 weeks. Recently AC was regarded as a contraindication for LC17,19. However as the experience is increased difficult operations are done in acceptable success (20-23). We found that, of the patients admitted with AC when treated with emergency LC showed no risk of conversion whereas in the patients with previous history of documented acute attacks the conversion risk were increased to 14.9 fold than the patients with no such history (40.7% vs. 4.4%, p<0 .001="" name="resultview">21. Yamashita Y, Takada T, Kawarada Y, Nimura Y, Hirota M, Miura F, et al. Surgical treatment of patients with acute cholecystitis: Tokyo Guidelines. J Hepatobiliary Pankreat Surg 2007; 14:91-97.
22. Wilson RG, Macintyre IMC, Nixon SJ, Saunders JH, Varma JS, King PM. Laparoscopic cholecystectomy as a safe and effective treatment for severe acute cholecystitis. BMJ 1992;305:394-6.
23. Wallace DH, O'dwyer PJ. Effect of no-conversion policy on patient outcome following laparoscopic cholecystectomy. Br J Surg 1997;84:1680-2.
24. Wiebke EA, Pruitt AL, Howard TJ, Jacobson LE, Broadie TA, Goulet RJ Jr, Canal DF. Conversion of laparoscopic to open cholecystectomy. An analysis of risk factors. Surg Endosc 1996;10:742-5.
25. Lo CM, Fan ST, Liu CL, Lai EC, Wong J. Early decision for the conversion of laparoscopic to open cholecystectomy for treatment of acute cholecystitis. Am J Surg 1997;173:513-7.


Correspondence:

Mehmet KAPLAN, M.D.
Özel NCR International Hastanesi, Gaziantep
e-mail: dr.kaplan27@gmail.com
Acceptance date: 24.08.2007