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Ann Surg. Mar 2000; 231(3): 339–344.
PMCID: PMC1421004

Standardization of Surgeon-Controlled Variables

Impact on Outcome in Patients With Acute Cholecystitis



To examine the effect of standardization of surgeon-controlled variables on patient outcome after cholecystectomy for two cohorts of patients with acute cholecystitis (AC).

Summary Background Data

Laparoscopic cholecystectomy (LC), when performed efficiently and safely, offers patients with AC a more rapid recovery and decreases the length of stay, thus reducing the health care utilization. Numerous studies have focused on the characteristics of patients with AC that may predict the conversion of LC to open cholecystectomy. However, analysis of these factors offers little insight for improving the outcome of patients with AC, because patient-controlled variables are difficult to influence. In the present study, treatment variables that were under the surgeon’s control were standardized and the effects of these changes on the outcome of patients with AC were quantified.


Beginning in August 1997, a standardized treatment protocol was initiated for patients with suspected AC. LC was initiated as early as practical from the time of admission. All operations were performed in a specially equipped and staffed laparoscopic surgery suite, and all patients were supervised by one of two attending surgeons with a special interest in laparoscopic interventions. Two cohorts of patients with AC were retrospectively analyzed: 39 patients from the 12 months before initiation of this protocol (period 1) and 49 patients from the 12 months after its inception (period 2). Medical records were reviewed for demographic, perioperative, and outcome data. Surgical reports were reviewed to ascertain the reason for conversion and whether laparoscopic technical modifications were used.


No significant difference was noted between the groups with regard to patient demographics, clinical presentation, or radiologic or laboratory parameters. After protocol initiation, patients received definitive treatment closer to the time of admission and had a greater percentage of laparoscopically completed cholecystectomies. Furthermore, the patients in period 2 had a significantly decreased postoperative length of stay and hospital charges than the earlier ones. Complications were infrequent and not significantly different between the groups. Two or more laparoscopic technical modifications were used in 95% of the successful LCs during period 2 versus 33.3% during period 1.


By controlling when, where, and by whom LC for AC was performed, the authors have significantly improved the percentage of cholecystectomies that were completed laparoscopically. This has led to improved outcomes and lower hospital charges for patients with AC at this municipal hospital.

When laparoscopic cholecystectomy (LC) was introduced, acute cholecystitis (AC) was considered a relative contraindication to the minimally invasive approach. As a result, many patients with AC underwent open cholecystectomy (OC), or the procedures were converted from LC to OC when acute gallbladder inflammation was encountered. As surgeons gained experience with laparoscopic surgery, numerous studies have demonstrated that LC for AC can be performed safely and effectively. 1–6 Reported conversion rates for LC in AC vary markedly and are still quite high, with reported rates between 7% and 30%. 5,7–11

Studies attempting to identify risk factors for conversion have largely analyzed variables such as patient characteristics and radiographic findings. Although these studies may identify patients who have more technically challenging cholecystectomies, they offer little in the way of improving outcome in any given patient after presentation. We cannot change many of the characteristics of the patients we encounter, but we can modify treatment variables under our control. For example, an operating surgeon’s experience with LC for AC, time from emergency admission to LC, and equipment availability and familiarity have been retrospectively identified as variables that may affect conversion rates from LC to OC in patients with AC. 10–16 We used these observations to design a prospectively applied treatment protocol for patients with suspected AC at our municipal hospital. The purpose of this study was to quantify the effects of these changes on the outcome of patients with AC.


Beginning in August 1997, a standardized treatment protocol was initiated for patients with suspected AC. In addition to fluid resuscitation and intravenous antibiotics, LC was initiated as soon as practical from the time of admission. All operations were performed in a specially equipped and staffed laparoscopic surgery suite, and all cases were supervised by one of two attending surgeons with a special interest in laparoscopic biliary interventions (RMN, HFM). This protocol standardized the “who, when, and where” in the treatment of patients with AC. Technical modifications known to facilitate LC for AC were used at the discretion of one of the two attending surgeons involved (Table 1) .

Table thumbnail

Before this protocol was implemented, the management of patients with AC was based on the individual bias of the house staff and supervising attending. Cholecystectomies in these patients were supervised by a rotating schedule of surgical staff in any of the 15 operating rooms staffed by general operating room personnel. Finally, in the first time period, several attending surgeons favored a “cooling off” period for patients with AC, whereas others favored an urgent approach to surgical management.

Between August 1996 and July 1998, 444 patients underwent cholecystectomy at Bellevue Hospital Center, a large municipal teaching hospital in New York City. This 2-year period was chosen because it encompassed 1 year before (period 1) and 1 year after (period 2) the initiation of the treatment protocol. Histopathologic evidence of acute gallbladder inflammation was present in 28% of the total 444 patients. Admission records and surgical reports were retrospectively reviewed to identify patients who had a clinical presentation and course consistent with AC. Inclusion criteria were:

  • • Emergency room admission
  • • Elevated white blood cell count, fever, or Murphy’s sign
  • • Radiologic evaluation consistent with the clinical diagnosis of AC (ultrasound, computed tomography scan, or hepato-iminodiacetic acid scan)
  • • Intraoperative evidence of acute gallbladder inflammation
  • • Histopathologic confirmation of AC

Hospital and follow-up clinic medical records were retrospectively reviewed and demographic information, duration of symptoms from onset to admission, surgical reports, and outcome variables were recorded. Outcome variables analyzed included time from admission to operating room, postoperative complications, postoperative length of stay (LOS), and hospital charges. Documentation of all laparoscopic technical modifications and type of cholecystectomy performed (i.e., LC vs. OC) were recorded and quantified. Postoperative follow-up was obtained from clinic progress notes. Hospital charges for admitted surgical ward patients during the study period were based on a per diem rate of $2,520. Statistical analysis was performed using the Student t test and the chi-square test, with significance set at P ≤ .05.


Eighty-eight patients met all the inclusion criteria during the 2-year period (39 during period 1, 49 during period 2). The most common reasons for exclusion were patients with histopathologic evidence of AC who were electively admitted for LC for biliary colic and patients admitted to other hospital services who had the diagnosis of AC made during their hospital stay. Both were excluded from the study because they were not admitted from the emergency room. The patients’ age, sex, duration of symptoms from onset to admission, clinical presentation, and white cell count at admission were similar in both groups (Table 2). Radiographic studies performed on presentation and the histopathologic degree of inflammation were similar as well (Tables 3 and 4) . Also, 5.1% (n = 2) and 2.0% (n = 1) of cholecystectomy specimens during period 1 and period 2, respectively, were acalculous in nature on pathologic examination.

Table thumbnail

During period 2, there was significantly less time from admission to operation and a significant increase in the percentage of successful LCs completed. LC was completed in 15% of patients in period 1 and in 88% in period 2. Similarly, 74% of the patients required conversion from LC to OC in period 1, compared with 8% in period 2. Further, 41% of patients in period 1 underwent primary open procedures (i.e., no laparoscopic attempt), compared with 4% in period 2. Finally, 85% of patients in period 1 required OCs (i.e., conversions plus open procedures), compared with 12% in period 2 (Fig. 1).

figure 6FF1
Figure 1. Types of operations performed during the two study periods. LC, laparoscopic cholecystectomy; CCKYs, cholecystectomies. Note the significant increase in successful LCs and the decreased conversion rate in period 2 (vs. period 1, *P < ...

Period 2 patients had a significantly shorter LOS than period 1 patients. Time to operation (2.69 vs. 1.32 days), postoperative LOS (5.74 vs. 3.65 days), and total LOS (8.43 vs. 4.97 days) were all significantly reduced in period 2 versus period 1 (P < .01;Fig. 2). Accordingly, hospital charges based on the per diem rate were lower in period 2, reflecting the significantly reduced LOS from period 1 (P < .001;Fig. 3).

figure 6FF2
Figure 2. Time to operation from admission, postoperative length of stay, and total length of stay. Note the significant reduction in length of stay during period 2 (vs. period 1, *P < .01). LOS, length of stay.
figure 6FF3
Figure 3. Hospital charges as calculated on a per diem basis at Bellevue Hospital. Note the significant reduction in hospital charges during period 2 (vs. period 1, *P < .001).

Operations performed during the study periods are presented in Figure 1. Reasons for beginning with OC were primarily due to surgeon preference and experience as well as equipment availability in period 1. The two operations begun as OC in period 2 were in patients with previous gastric surgery. Reasons for conversion were similar between the two study periods and included inability to grasp the gallbladder secondary to distention or necrosis, inability to delineate critical structures, and hemorrhage from friable tissues. The number of LCs completed laparoscopically was significantly increased, reflecting the decreased conversion rate for period 2 versus period 1 (P < .0001;Fig. 1).

Laparoscopic technical modifications were performed significantly more often and in greater number per operation in period 2. During period 1, only two of the six successfully completed LCs used two or more of these modifications. No operations performed during period 1 used more than four maneuvers. During period 2, 41 of the 43 successful LCs (95%) used two or more modifications, and 35 of the 43 successful LCs (81%) during this period used four or more. Specifically, laparoscopic gallbladder decompression, focused dissection, intraoperative cholangiography, extraction devices, and drain placement were used in 84%, 77%, 88%, 84%, and 78% of period 2 operations, respectively.

Complications were similar for both groups of patients. There were no major bile duct injuries or perioperative deaths. There was one transient bile leak in each group; both resolved without surgery. Wound infection developed in four patients in period 1 (one patient who underwent LC, two patients with a converted procedure, and one patient who underwent OC). There were two wound infections during period 2 (one patient who underwent LC, one patient with a converted procedure). Four patients during period 1 had clinical and radiographic evidence of pneumonia (one patient who underwent LC, three who underwent OC).


In the early experience with laparoscopic general surgical interventions, many surgeons considered AC a relative contraindication to LC, claiming that the inflammation, edema, and obscured anatomy associated with AC led to an increased number of complications. 17–19 As a result, many patients with AC underwent OC, and many attempted LCs were converted to OCs. As laparoscopic general surgery has evolved, numerous studies, including the present one, have demonstrated that LC for AC can be performed safely, and most patients can enjoy the benefits of the minimally invasive approach. 1–6 Although conversion rates of 7% to 30% have been reported by groups with specific laparoscopic interests, the true rate of conversion, or the failure to attempt LC in patients with AC, is largely unreported. 5,7–11 This is illustrated by the low rate of successful LCs in patients with AC treated at our hospital during period 1.

After the magnitude of this problem was identified, we sought ways to improve the outcome. To this end, we chose to standardize the variables that we could manipulate. Specifically, in our municipal hospital, we were able to control the “when, where, and who” treatment variables in the management of patients with AC. After initiation of an institutional protocol for the treatment of patients with AC, the “when” became as soon as practical from admission, and the “where” became a specially equipped and staffed laparoscopic surgery suite. The “who” became the house staff supervised by surgeons with special interest in therapeutic laparoscopy. By controlling these variables, we have demonstrated a marked increase in the percentage of cholecystectomies completed laparoscopically in patients with AC. This has resulted in a significantly reduced hospital LOS and charges.

Over the years, patients with AC have presented management challenges to surgeons, resulting in a variety of treatment strategies. Traditionally, patients with AC were admitted to the hospital for intravenous fluids and antibiotics, they were discharged after the acute symptoms subsided, and they returned 6 to 8 weeks later for an interval cholecystectomy. This traditional management was challenged because many patients had a recurrent episode of AC during this interval, often requiring emergent surgical intervention. This “conservative” management has largely been abandoned, because numerous studies have reported the safety and cost effectiveness of early cholecystectomy for AC. 20–25 In the laparoscopic era, these studies have been repeated, and the results support performing early LC for patients with AC. 7,11,13–15,26

The pathophysiologic basis for these results lies in understanding the progression of the acute inflammatory process. Early in the course of AC, the inflamed, edematous tissues are often helpful in delineating tissue planes. As the inflammatory process continues, these normal tissue planes are replaced by dense, fibrotic adhesions that make dissection difficult. Although the duration of a patient’s symptoms before presentation is a fixed variable not under the control of the surgeon, the time after hospital presentation until surgical treatment can be influenced by surgical decision making. Thus, the “when” to perform cholecystectomy in our treatment protocol became as soon as practical after diagnosis. After the initiation of the treatment protocol, the average time to the operating room for patients was significantly reduced (1.32 vs. 2.69 days, P < .01).

Other factors that have been shown to contribute to the rate of conversion from LC to OC in patients with AC are staff who are unfamiliar with laparoscopic techniques and, more importantly, the lack of proper laparoscopic instruments for emergency operations. 16 We recognized this as a problem in our institution and made changes in our operating room policies. Before the institution of our protocol, laparoscopic procedures were performed in all operating suites with any team of operating personnel. We believed this was detrimental to all patients undergoing laparoscopic procedures, and in particular those undergoing technically challenging LCs for AC. This was the rationale for the creation of a specially equipped and staffed laparoscopy suite. We believe that this variable was important in decreasing the conversion rate during the study period.

Numerous studies have focused on patient characteristics that may predict conversion from LC to OC. 11,12,16 Several preoperative factors have been reported to be independently correlated with an increased risk of conversion to OC. 3,6–8,11,12,16,27–29 Although these studies may help predict which patients will have difficult gallbladders to remove laparoscopically, they offer little in the way of how to improve the outcome in all patients with AC. In addition, we used many of these descriptive characteristics (e.g., emergency room presentation, elevated white blood cell count) in the inclusion criteria for our study, because many are simply expected findings in patients with AC. Accordingly, the clinical, laboratory, and radiologic parameters between the two groups in our study were similar (Table 2). Other studies have reported that the surgeon’s experience with LC for AC has an impact on the successful completion of the procedure. For example, several studies have identified senior surgeons, inexperienced surgeons, resident surgeons, and surgeons at particular hospitals (i.e., Veterans Administration hospitals) to be independent risk factors for conversion to open procedures in patients with AC. 5,12,16,28,30,31

Taking these two observations into account, an Austrian group has recently reported a prospectively modified treatment protocol for patients with AC. A list of conversion risk factors is identified on presentation. After identifying conversion risk factors, the patient is given an LC difficulty score. Patients at high risk for conversion are operated on by surgeons experienced with LC for AC. Patients at low risk for conversion are operated on by surgeons not necessarily experienced at performing LC in the setting of AC. 29

In the current study, we sought to identify potentially difficult cholecystectomies and to control prospectively the variables under our control. The “who” variable after protocol initiation was limited to two attending surgeons with a special interest in laparoscopic interventions and experience with LC for AC.

One of the main reasons why surgeon experience with LC for AC is critical to a successful laparoscopic procedure is the breadth of laparoscopic maneuvers required to facilitate LC in the setting of acute inflammation. These technical modifications (Table 1) are not new and have been reported by others. 4,9 Early decompression of the distended gallbladder allows proper grasping of the fundus for proper exposure to the triangle of Calot. Puncture of the fundus with a specialized suction-irrigation device was followed by immediate closure of the puncture site with a pretied loop. This maneuver provides a convenient handle for the retracting grasper and does not commit the grasper to occluding the decompression hole for the rest of the operation. A focused dissection, limited to the gallbladder–cystic duct junction, is not always possible, depending on the adhesions to other structures. However, limiting dissection avoids hemorrhage that may obscure the surgical field.

Although the role of laparoscopic intraoperative cholangiography remains controversial, we believe it is important in the setting of acute gallbladder inflammation. 32–34 In AC, vital structures are often difficult to delineate, and intraoperative cholangiography, particularly digital real-time fluoroscopy, provides an invaluable mapping of the biliary tree that aids in the safe and successful performance of LC for AC.

Extraction of the acutely inflamed gallbladder through the umbilicus almost always requires an extraction bag. Because we decompress almost all the acutely inflamed gallbladders, extraction through the abdominal wall unprotected would result in infected bile and stone contamination. The use of closed suction drains in the gallbladder fossa is controversial as well. Subhepatic drain placement was our practice in OC for AC based on the possibility of infected bile mixing with blood and irrigation fluid in the gallbladder bed, resulting in abscess formation; thus, we have persisted with this practice in the laparoscopic setting.

By controlling when, where, and by whom LC for AC is performed, we have significantly improved the percentage of cholecystectomies that are completed laparoscopically. Further, decreased preoperative and postoperative stays and reduced hospital charges at our municipal hospital resulted after initiation of a standardized treatment protocol for patients with AC. Standardization of surgeon-controlled variables improves outcome variables in patients with AC.


Correspondence: Richard M. Newman, MD, Dept. of Surgery, Bellevue Hospital, 27th St. & First Ave., 15th fl., New York, NY 10016.

Accepted for publication August 31, 1999.


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