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Tom Reeve Academic Surgical Clinic · St Leonards
Research summary · ANZ Journal of Surgery 2025
In 2,633 laparoscopic cholecystectomies performed by Professor Hugh's unit between 1998 and 2020, 78% were straightforward and 22% were difficult on the North Shore grading system. Difficult operations took longer and were more often converted to open surgery, with more bile leaks, longer hospital stays and more readmissions. The most difficult grade added an estimated AU$2,096 to AU$3,025 per patient in hospital costs.
Most gallbladder operations are straightforward. Difficulty is more likely after urgent presentations, jaundice or pancreatitis, so planning for those cases matters.
The authors recommend anticipating difficult operations before surgery so the right time, equipment and surgical experience are available on the day.
Read the patient guide→Laparoscopic cholecystectomy removes the gallbladder through four small incisions, and more than 57,000 were performed in Australia in 2020. Compared with open surgery it means a shorter hospital stay, fewer complications and an earlier return to normal life, which is why it is the standard operation for gallstones in Australia.
In this series a standard four-port technique was used and an X-ray of the bile ducts during surgery (intra-operative cholangiogram) was attempted routinely, in 97% of patients. The cholangiogram checks the anatomy of the bile ducts and looks for stones that have slipped out of the gallbladder. Patients had a planned overnight stay with physical and medication-based protection against blood clots.
The key safety step is the critical view of safety, where the surgeon clears the tissue around the cystic duct and artery until both are clearly identified before anything is divided. When inflammation makes that view impossible to achieve safely, the surgeon has options that include a subtotal cholecystectomy (removing most of the gallbladder), placing a drain, or converting to an open operation. Choosing well between them is a matter of training and experience, and those decisions are the main protection against a bile duct injury.
Professor Hugh's unit records the North Shore grade during every operation, based on what the surgeon actually sees. The grade is written in the operation note at the time, which makes it far more reliable than estimating difficulty afterwards from the length of the operation or whether it was converted to open surgery.
Grades 1 and 2 are classed as straightforward and Grades 3 and 4 as difficult. Of 2,633 operations, 413 (about 16%) were Grade 3 and 170 (about 6%) were Grade 4.
| Grade | What the surgeon finds | Patients in this study |
|---|---|---|
| Grade 1 | Thin-walled, normal-looking gallbladder with no adhesions | Grades 1 and 2 combined: 2,050 (78%) |
| Grade 2 | Mildly abnormal gallbladder (slightly thick-walled or distended) or thin, filmy adhesions | Included above |
| Grade 3 | Moderately abnormal gallbladder (swollen, mucocele or large and distended) or moderate adhesions | 413 (16%) |
| Grade 4 | Severely inflamed or grossly abnormal gallbladder (for example necrotic or perforated) or extensive adhesions | 170 (6%) |
The differences grow with each grade. A Grade 4 gallbladder takes more than twice as long to remove, the bile duct X-ray succeeds less often, and the chance of everything going to plan falls from about seven in ten patients to three in ten. The unit's overall conversion rate to open surgery was 1.0%, at the low end of the 1% to 15% range reported in the literature, and it rose to 5.3% for Grade 4 operations, where the usual reason was that the critical view of safety could not be achieved.
Serious problems were uncommon at every grade. There were no major bile duct injuries in 2,633 operations, and every bile leak was the minor type that comes from the cystic duct stump or a small duct in the gallbladder bed. Bleeding and returns to theatre each occurred in 0.5% of patients and were no more frequent in difficult operations.
| Measure | Grades 1 and 2 | Grades 3 and 4 | Grade 4 only |
|---|---|---|---|
| Operating time | 40 min | 60 min | 90 min |
| Hospital stay after surgery | 1 day | 1 day | 2 days |
| Bile duct X-ray successful | 96.6% | 89.8% | 79.6% |
| Converted to open surgery | 0.7% | 2.1% | 5.3% |
| Bile leak | 0.4% | 1.4% | 1.8% |
| Any complication | 16.4% | 21.8% | 24.7% |
| Readmission | 1.6% | 3.4% | 3.5% |
| Textbook outcome | 72.2% | 52.0% | 30.6% |
Men made up 28% of straightforward operations and 48% of difficult ones, rising to 61% at Grade 4. Difficult findings were also linked to jaundice before surgery (4.5% compared with 2.0%), a higher Charlson Comorbidity Index (a score of other medical conditions), and operations done urgently or within four weeks of an acute admission. Half of all Grade 4 operations were urgent or semi-urgent, compared with 7% of straightforward ones.
Grade 4 patients were younger on average, with a median age of 44 compared with 52, which reflects how often severe inflammation follows an acute attack. Other studies add age over 60, previous upper abdominal surgery, obesity, inflammation seen on the ultrasound and a past episode of severe acute cholecystitis to the list of warning signs.
Surgical trainees were the principal operator in 17% to 19% of operations at every grade, always under close consultant supervision, and their involvement did not predict a poorer result.
The study measured a textbook outcome, a recovery with everything going to plan: the operation finished by keyhole, no complications, one night in hospital, and no readmission or death within 30 days. Overall, 68% of patients met every part of that definition.
Four factors independently predicted missing it. Grade 4 findings made a less than ideal recovery 5.5 times more likely, and needing a bile duct exploration to clear stones carried a similar increase (5.6 times). Presenting with gallstone pancreatitis almost doubled the odds (1.9 times), and each extra point on the comorbidity score added about 9%.
Using 2022 Royal North Shore Hospital costings of AU$1,400 per hour for a fully staffed operating theatre and AU$929 per night in a ward bed, the authors estimated the extra cost of a Grade 4 operation compared with a straightforward one.
The additional 50 minutes in theatre added about AU$1,167, the extra night added AU$929, and the higher readmission rate added roughly another AU$929 for each readmission, giving a total of AU$2,096 to AU$3,025 per patient. These figures leave out imaging, repeat procedures and medicines, so the true cost is higher. Australian national hospital cost data show costs can more than double when a difficult operation has to be converted to open surgery.
The authors' central recommendation is to anticipate difficulty before the day of surgery. Your history, blood tests and ultrasound usually signal a harder operation, which allows it to be booked during regular working hours with experienced theatre staff and specialist instruments such as suitable graspers and devices to decompress a distended gallbladder.
They also recommend senior surgical input for every urgent or semi-urgent gallbladder operation. An experienced hepatobiliary surgeon was involved in every operation in this series, and the authors consider that a likely reason the conversion rate stayed low and complications rose only modestly in difficult cases.
For patients, the practical step is to tell your surgeon about previous attacks, any yellowing of the skin or eyes, pancreatitis and earlier abdominal operations, because that history shapes how the operation is planned.
The data come from one consultant surgeon's practice over 22 years, which kept technique and decision-making consistent but may limit how far the results apply to units with many surgeons. The analysis was retrospective, technology improved over the study period, and operating time was recorded for about half the patients. The authors call for every surgeon to record the operative findings in a standard way so results can be compared across hospitals.
Keyhole gallbladder removal (laparoscopic cholecystectomy) is one of the most common operations, and most are straightforward. In Professor Hugh's series of 2,633 operations, 78% had straightforward findings, there were no major bile duct injuries, and every bile leak was the minor type that comes from the cystic duct stump or the gallbladder bed. About one operation in five was difficult, and those carried more complications and longer hospital stays.
In this study the least difficult operations took a median of 40 minutes and the most difficult grade took a median of 90 minutes. Your surgeon can usually anticipate a longer operation from your history, blood tests and scans.
The median hospital stay was one day after a straightforward operation and two days after the most difficult grade. Stays were also longer when the operation was converted to open surgery or a bile leak needed treatment. Read the gallbladder removal recovery guide.
Difficult findings were more common in men, in people with jaundice or several other medical conditions, and in urgent operations after an acute presentation. Repeated attacks of inflammation leave scarring around the gallbladder, which is one reason earlier planned surgery is often easier.
Published conversion rates range from 1% to 15%. In this series of 2,633 operations the conversion rate was 1.0%, rising to 5.3% for the most difficult Grade 4 gallbladders, where the usual reason was that inflammation or scarring made the anatomy impossible to see safely through the keyhole approach.
The critical view of safety is the point where the surgeon has cleared the tissue around the cystic duct and cystic artery so both are clearly identified before anything is clipped or divided. It is the main step that protects the common bile duct. When inflammation prevents it, options include removing most of the gallbladder (subtotal cholecystectomy), placing a drain or converting to open surgery.
A textbook outcome means the operation was completed by keyhole, there were no complications, the hospital stay was one night, and there was no readmission or death within 30 days. In this study 72% of straightforward operations met that standard compared with 31% of the most difficult grade.
Using Royal North Shore Hospital costings, the most difficult operations added an estimated AU$2,096 to AU$3,025 per patient through longer theatre time, an extra night in hospital and more readmissions. The authors describe these figures as conservative because imaging, repeat procedures and medicines were left out.
Yu Y, McKay SC, Bhimani N, Tranter-Entwistle I, Hugh TJ. Clinical and financial impact of a 'difficult' laparoscopic cholecystectomy. ANZ J Surg. 2025;95:926-933. doi:10.1111/ans.70113
Open access (CC BY-NC-ND), read free on the publisher's site.
Reviewed by Professor Thomas J. Hugh, MBBS, FRACS, MD
Last reviewed 24 October 2026.
Last updated 25 August 2026