Preliminary experience with intracorporeal laparoscopic ultrasonography using a sector scanning probe. A prospective comparison with intraoperative cholangiography in the detection of choledocholithiasis

Cost-effective Decisions in Detecting Silent Common Bile Duct Gallstones During Laparoscopic Cholecystectomy

OBJECTIVE

To evaluate the cost-effectiveness of routine intraoperative ultrasonography (IOUS), cholangiography (IOC), or expectant management without imaging (EM) for investigation of clinically silent common bile duct (CBD) stones during laparoscopic cholecystectomy.

BACKGROUND

The optimal algorithm for the evaluation of clinically silent CBD stones during routine cholecystectomy is unclear.

METHODS

A decision tree model of CBD exploration was developed to determine the optimal diagnostic approach based on preoperative probability of choledocholithiasis. The model was parameterized with meta-analyses of previously published studies. The primary outcome was incremental cost per quality-adjusted life year (QALY) gained from each diagnostic strategy. A secondary outcome was the percentage of missed stones. Costs were from the perspective of the third party payer and sensitivity analyses were performed on all model parameters.

RESULTS

In the base case analysis with a prevalence of stones of 9%, IOUS was the optimal strategy, yielding more QALYs (0.9858 vs 0.9825) at a lower expected cost ($311 vs $574) than EM. IOC yielded more QALYs than EM in the base case (0.9854) but at a much higher cost ($1122). IOUS remained dominant as long as the preoperative probability of stones was above 3%; EM was the optimal strategy if the probability was less than 3%. The percentage of missed stones was 1.5% for IOUS, 1.8% for IOC and 9% for EM.

CONCLUSIONS

In the detection and resultant management of CBD stones for the majority of patients undergoing laparoscopic cholecystectomy, IOUS is cost-effective relative to IOC and EM.

Value of contrast-enhanced magnetic resonance cholangiography in patients undergoing laparoscopic cholecystectomy

Laparoscopic cholecystectomy (LC) is the preferred treatment of symptomatic gallstone disease. Biliary injury during LC is still a serious problem. Knowledge of anatomic detail is important for not encountering the injury. Magnetic resonance cholangiography (MRC) is a noninvasive method for imaging the biliary ducts. However, MRC has many drawbacks such as not showing anatomic structures in detail and respiratory motion. In this study, contrast-enhanced MRC is used to show cystic ducts that are not seen by MRC. Reasons for patient referral for MRC and contrast-enhanced MRC included suspicion of cholecystolithiasis, adenomyomatosis, and gallbladder polyp. Our results show that routine MRC revealed cystic ducts in 38 patients (77.5%) and contrast-enhanced MRC in 46 patients (93.8%). Intraoperative cholangiography (IOC) was taken as gold standard for all patients. We found that contrast-enhanced MRC can provide a useful supplement to MRC in patients with nonvisualized cystic ducts by MRC. To our knowledge, this is the first study of visualization of cystic duct in patients undergoing LC depicted by both MRC and contrast-enhanced MRC.

Value of contrast-enhanced magnetic resonance cholangiography in patients undergoing laparoscopic cholecystectomy

Laparoscopic cholecystectomy (LC) is the preferred treatment for symptomatic gallstone disease. Biliary injury during LC is still a serious problem. Knowledge of anatomic detail is important for not encountering the injury. Magnetic resonance cholangiography (MRC) is a noninvasive method for imaging the biliary ducts. However, MRC has many drawbacks such as not showing anatomic structures in detail and respiratory motion. In this study, contrast-enhanced MRC was used to show cystic ducts that are not seen on MRC. Reasons for patient referral for MRC and contrast-enhanced MRC included suspicion of cholecystolithiasis, adenomyomatosis, and gallbladder polyp. Our results show that routine MRC revealed cystic ducts in 38 patients (77.5%) and contrast-enhanced MRC in 46 patients (93.8%). Intraoperative cholangiography (IOC) was taken as gold standard for all patients. We found that contrast-enhanced MRC can provide a useful supplement to MRC in patients with cystic ducts not seen on MRC. To our knowledge, this is the first study of visualization of a cystic duct in patients undergoing LC depicted by both MRC and contrast-enhanced MRC.

Potential of laparoscopic ultrasonography as an alternative to operative cholangiography in the detection of bile duct stones

BACKGROUND

Intraoperative cholangiography (IOC) is time consuming, requires radiation and sometimes fails. In contrast, laparoscopic ultrasonography (LUS) is a comparatively quick, safe and non-invasive technique. The aim of this study was to assess the potential of LUS as an alternative to IOC.

METHODS

LUS was performed on 367 patients undergoing laparoscopic cholecystectomy. Laparoscopic duct exploration was performed in the presence of duct stones. Data were collected prospectively. The presence or absence and number of duct stones detected by LUS were recorded. The maximum bile duct diameter determined by LUS was compared with a preoperative ultrasonographic measurement according to age and the presence of duct stones. The final arbiter was the demonstration of stones removed at laparoscopic duct exploration (59 patients) or subsequently by endoscopic retrograde cholangiopancreatography (two patients).

RESULTS

LUS visualized the CBD in 99 per cent of patients and the common hepatic duct in 92 per cent. It identified stones in 56 of the 61 patients with duct stones. No stones were demonstrated in the remaining 306 patients (sensitivity 92 per cent, specificity 100 per cent, positive predictive value 100 per cent, negative predictive value 98 per cent). LUS underestimated the total number of stones in 18 per cent of patients with common duct stones. The mean common bile duct diameter was 5.0 mm before operation and 5. 9 mm during the procedure in patients without duct stones, rising significantly to a mean of 9.2 mm before operation and 11.2 mm at LUS in those with duct stones (P < 0.0001).

CONCLUSION

The combination of the demonstration of duct stones and bile duct diameter measurement makes LUS a potential replacement for IOC. Improved demonstration of the common hepatic duct would be advantageous.

Laparoscopic ultrasound for the detection of hepatic metastases during laparoscopic colorectal cancer surgery

PURPOSE

The search for liver metastases before surgery forms an accepted part of colorectal cancer surgical practice. Intraoperative ultrasound and manual palpation of liver together form the criterion standard as far as screening for metastases is concerned. However, extracorporeal imaging, such as ultrasound and magnetic resonance imaging, are also widely used. The purpose of this study was to demonstrate the efficacy of laparoscopic ultrasound scan in detection of liver metastases during laparoscopic colorectal cancer surgery by comparison with conventional imaging modalities.

METHODS

A prospective, controlled study was undertaken. A total of 76 consecutive patients undergoing laparoscopic colorectal resections for malignancy were recruited. Patients underwent preoperative liver ultrasound scan and intraoperative blinded laparoscopic ultrasound scan examination performed by a single surgeon. Contrast-enhanced magnetic resonance imaging was performed within 30 days of surgery.

RESULTS

Conventional ultrasound scan was negative in all cases. Metastases were identified during simple laparoscopic inspection of the liver in one case. Two cases shown by laparoscopic ultrasound scan to have definite metastases were confirmed by magnetic resonance imaging. In seven further instances laparoscopic ultrasound scan identified suspicious liver masses. In three cases these were confirmed to be metastases at magnetic resonance imaging; one was confirmed as a cyst, and the remaining three suspicious lesions were confirmed at serial magnetic resonance imaging scans to be benign and of no significance.

CONCLUSION

Laparoscopic ultrasound scan with a flexible-tipped probe permits satisfactory hepatic examination. It is superior to conventional ultrasound scan and seems to be as effective as magnetic resonance imaging, although the latter modality is still required to delineate identified lesions.

Laparoscopic ultrasound (LUS) in gastrointestinal surgery

Intraoperative ultrasonography during abdominal surgery became widespread by availability of high-frequency, high-resolution transducers. It's usefulness has particularly been proven in biliar and gastrointestinal surgery. Our objective was to examine the method in laparoscopic cholecystectomy and in laparoscopic staging of malignancies of the upper gastrointestinal tract as well. Lapaoscopic ultrasound (LUS) examination was performed in 567 patients operated on because of biliary stones and in 12 patients with carcinoma in the upper part of the gastrointestinal tract. In accordance to the known criteria endoscopic retrograde cholangiopancreatography (ERCP) was performed in 89 patients, and additionally, ERCP was performed in 58 patients because of dilated common bile duct. Choledochal stones were demonstrated in 72 of the 147 patients. Laparoscopic ultrasonography demonstrated preoperatively undetected bile duct stones in 18 of these patients (12%). In 294 other patients without any criteria of bile duct stones, laparoscopic ultrasonography demonstrated bile duct stones in 11 patients (4%). Laparoscopic ultrasonography in 12 patients with proximal gastrointestinal malignancies demonstrated inoperability in all of the patients. Laparotomy could thereby be avoided. LUS examination is an ideal operative tool as it is safe, reproducible and requires no special patient preparation or positioning. The method of imaging is therefore justified for patients undergoing laparoscopic surgery because of biliary stones and gastrointestinal surgery.

Role of laparoscopic ultrasonography in the management of patients with oesophagogastric cancer

BACKGROUND

Laparoscopy and laparoscopic ultrasonography (lapUS) have been shown to improve the staging of patients with oesophagogastric cancer but there remains doubt as to whether most benefit follows laparoscopy alone and how much is contributed by the addition of lapUS.

METHODS

The role of lapUS in surgical decision making was evaluated prospectively in a consecutive series of patients with oesophagogastric cancer following conventional radiological assessment. The results of the lapUS findings over and above the laparoscopic findings were documented in order to identify the additional benefit of lapUS.

RESULTS

After initial conventional assessment 41 patients were considered unsuitable for surgery and treated by palliation, with a further 25 patients proceeding to surgery without laparoscopy. Of the 93 patients who underwent laparoscopy, 18 were shown to have irresectable disease and avoided further surgery; a further seven avoided inappropriate surgery by the addition of lapUS. The open-close laparotomy rate was reduced from five of 25 in patients who did not undergo laparoscopy to nine (12 per cent) of 75 by the introduction of laparoscopy and to two (3 per cent) of 68 with the addition of lapUS.

CONCLUSION

Laparoscopy alone prevented unnecessary surgery in 18 (19 per cent) of 93 patients with oesophagogastric cancer and the addition of lapUS identified a further seven patients (8 per cent) in whom unnecessary surgery was avoided.

Assessment of the biliary tract by ultrasonography and cholangiography during laparoscopic cholecystectomy: a prospective study

OBJECTIVE

The introduction of laparoscopic cholecystectomy (Lap-chol) has induced routine cholangiography to map the biliary tree and identify common bile duct (CBD) stones. However, the use of more selective criteria for performing intraoperative cholangiography (IOC), drawbacks of IOC and experience with laparoscopic ultrasonography (LU) re-introduced intraoperative ultrasonography for the CBD. The purpose of this study was to compare the accuracy of LU and IOC to identify the anatomy of the CBD and the presence of stones.

METHODS

A total of 50 unselected patients undergoing elective laparoscopic cholecystectomy were evaluated by LU and IOC. Stones were found in three patients by IOC and could be confirmed by ultrasonography and CBD exploration in two.

RESULTS

Anatomic definition of the biliary tract and success of the procedure was better for LU (90 and 98%) than IOC (86 and 72%).

CONCLUSION

For Surgical groups with experience in LU this technique appears to become the standard technique to identify the anatomy of the CBD and assessment of CBD stones.

Laparoscopic ultrasonography versus operative cholangiography during laparoscopic cholecystectomy: review of the literature and a comparison with open intraoperative ultrasonography

BACKGROUND

Laparoscopic ultrasonography (LUS) has been used increasingly over the last several years as a new imaging modality. To define the role of LUS during laparoscopic cholecystectomy, we evaluated LUS by prospectively comparing it with operative cholangiography (OC), by reviewing the literature on LUS, and by retrospectively comparing it with intraoperative ultrasonography performed during open cholecystectomy.

STUDY DESIGN

LUS and OC were compared prospectively in 100 consecutive patients during laparoscopic cholecystectomy. The success rate of examination, the time required, the accuracy in diagnosing bile duct calculi, and the delineation of biliary anatomy were evaluated.

RESULTS

The success rate of examination was 95% for LUS and 92% for OC. The main reason for unsatisfactory LUS was incomplete visualization of the distal common bile duct. The time required was 8.2 minutes for LUS and 15.9 minutes for OC (p<0.0001). Nine patients had bile duct calculi. LUS had one false-negative result and OC had two false-positives and one false-negative. The accuracies of LUS and OC were comparable except for a slightly better positive predictive value of LUS (100% versus 77.8%; p>0.1). In a literature review, 12 recent prospective studies comparing LUS and OC and three studies on open intraoperative ultrasonography were reviewed. Twelve studies of LUS with a total of 2,059 patients demonstrated results similar to the present study. The success rate was 88% to 100% for both tests. The time for LUS was approximately 7 minutes, about half of the time needed for OC. Overall, LUS was associated with fewer false-positive results than OC; the positive predictive value and specificity of LUS were better, while the sensitivity and negative predictive value of LUS and OC were comparable. OC detected ductal variations or anomalies more distinctly than LUS. Compared with open intraoperative ultrasonography, LUS had a slightly lower success rate and required a slightly longer time because it was technically more demanding, but the two procedures had a similar accuracy for diagnosing bile duct calculi.

CONCLUSIONS

Because of their different advantages and disadvantages, LUS and OC can be used in a complementary manner. There is a learning curve for LUS because of its technical difficulty. Once learned, however, LUS can be used as the primary screening procedure for bile duct calculi because of its safety, speed, and cost-effectiveness. OC can be used selectively, particularly when ductal anatomic variations or anomalies or bile duct injuries are suspected.

Intraoperative abdominal ultrasonography

BACKGROUND

Ultrasonography during abdominal surgery has been reported since the 1960s, but its use did not become widespread until the recent availability of high-frequency, high-resolution transducers. This review discusses the application of intraoperative ultrasonography to open and laparoscopic abdominal surgery.

METHODS

A literature search (Medline) was undertaken. All papers pertaining to the subject matter that were located were included in the review.

RESULTS

Intraoperative ultrasonography influences surgical strategy in up to 50 per cent of liver resections for malignancy. It is the single most sensitive technique for the detection of occult hepatic metastases at the time of primary colorectal resection. In pancreatic surgery, intraoperative ultrasonography is of value in the localization of islet cell tumours and in the assessment of resectability of adenocarcinoma. The technique may also have a role in staging laparoscopy, and in the operative management of kidney and gastrointestinal diseases.

CONCLUSION

Ultrasonography is an ideal operative tool as it is safe, reproducible and requires no special patient preparation or positioning. It should be regarded as an essential component of major hepatobiliary and pancreatic procedures. The recent availability of flexible laparoscopic probes is likely to lead to a similar impact on minimal access surgery.

Laparoscopic and intraoperative ultrasound

OBJECTIVE

Intraoperative ultrasound has gradually expanded in the last two decades to a variety of surgical specialties and has gained an established role in many surgical procedures. Laparoscopic and thoracoscopic ultrasound are the latest modes of intraoperative sonography. They have been introduced mainly to overcome the two major drawbacks of laparoscopy, i.e. the capability of showing only the surface of the organs and the lack of manual palpation of the anatomical structures. We review and discuss the established and the most recent applications of intraoperative and laparoscopic ultrasound.

MATERIAL AND METHODS

The technology, new indications and results of intraoperative and laparoscopic ultrasound are reviewed. This review is based on the experience gained in our Institution during more than 500 surgical procedures and the analysis of the literature on the subject.

RESULTS

The yield of intraoperative and laparoscopic ultrasound consists in confirming preoperative studies and acquiring new data which would not be available otherwise. An important role of these techniques is determining the anatomy of the involved organs, thus providing a guidance for surgery. Both techniques have an important role in surgical decision-making, particularly with respect to hepatic, biliary and pancreatic malignancies. In some series the rate of major changes in the surgical strategy can be as high as 38%. A relatively new application of intraoperative ultrasound is the possibility to perform interstitial therapy of tumors at the time of the initial surgery. This can be useful, for example, in patients undergoing liver resection, when other unresectable lesions are found in a different segment or in the contralateral lobe. Finally, laparoscopic sonography has an important role in staging abdominal neoplasm, providing more information than preoperative imaging and laparoscopic exploration. This feature can be used to effectively stage gastrointestinal malignancies, pancreatic carcinoma, and abdominal lymphomas.

CONCLUSION

The application of intraoperative ultrasound will increase in the era of minimally access surgery and this will be dependent not only on technical improvements in ultrasound technology. Indeed, it may be expected that a variety of open procedures will be performed with videolaparoscopic monitoring and will need the guidance of laparoscopic sonography. In the future, the staging of abdominal neoplasm may be markedly improved by laparoscopy combined with laparoscopic ultrasound; however a cost-benefit analysis of these techniques and a comparison with preoperative tests should be carried out.

Intraoperative and laparoscopic ultrasound

Intraoperative ultrasound, whether during celiotomy or laparoscopy, plays an important role in assisting the surgeon in directing appropriate therapy for intra-abdominal diseases, particularly primary or metastatic malignancies involving the liver and primary malignancies of the pancreas and upper gastrointestinal tract. It is the most sensitive imaging technique for detecting small intraparenchymal lesions of the liver, pancreas, and other solid organs. Owing to its increased sensitivity over all commonly used preoperative imaging studies, it is responsible for changing the intraoperative treatment plan of these tumors in a significant percentage of cases. This is particularly true with respect to resectability. In the era of laparoscopic surgery, it replaces the surgeon's inability to palpate the liver and other organs during surgery. As surgeons use a laparoscopic approach with increasing frequency to treat intra-abdominal disease, they will have an increasing need to master the use of intraoperative ultrasound in order to render optimal care to their patients.

Abnormal common bile duct sonography. The best predictor of choledocholithiasis before laparoscopic cholecystectomy

We conducted a prospective study to determine the most reliable indicator of common bile duct stones before laparoscopic cholecystectomy. One hundred thirty-seven patients were referred for endoscopic retrograde cholangiography before laparoscopic cholecystectomy for suspected choledocholithiasis due to one or more of the following abnormalities: (a) altered liver function tests, (b) increased serum amylase levels, or (c) a dilated common bile duct (> 7 mm) with or without evidence of stones on sonography. Sensitivity, specificity, positive and negative predictive values, and the likelihood of the presence or absence of morbidity were calculated for 25 different variables. Common bile duct stones were detected in 63 (46%) patients. Abnormal result of sonography of the common bile duct was the best predictor of choledocholithiasis (p < 0.0001). Abnormalities of the combined liver function tests were statistically significant predictors only when combined with abnormal sonographic results. Improving liver function tests before endoscopy had a significant negative predictive value (p = 0.01). Stepwise logistic regression analysis showed that abnormal ultrasound and the presence of common bile duct stones on ultrasound were significant (p = 0.009 and p = 0.049, respectively). Abnormal result of sonography of the common bile duct is the best predictor of choledocholithiasis before laparoscopic cholecystectomy.

Laparoscopic ultrasonography during cholecystectomy

The routine use of intraoperative cholangiography during cholecystectomy has been debated extensively. Intraoperative ultrasonography was a quick, efficient alternative in open cholecystectomy. A prospective controlled trial to evaluate its usefulness in laparoscopic cholecystectomy is reported. Two groups of 100 patients each were examined during operation with laparoscopic ultrasonography and intraoperative cholangiography. In the first group an adapted urethral probe was used and in the second group a new specialized laparoscopic probe. Intraoperative cholangiography followed immediately after laparoscopic ultrasonography in each patient. In group 1 bile duct stones (n = 4) were detected with a sensitivity of 100 and 75 per cent, a specificity of 98 and 99 per cent, and an overall accuracy of 98 per cent for both ultrasonography and cholangiography. In group 2, 11 patients demonstrated common duct calculi. The sensitivity, specificity and overall accuracy for laparoscopic ultrasonography and intraoperative cholangiography were 91 and 64 per cent, 100 and 100 per cent, and 99 and 96 per cent respectively. The differences between groups 1 and 2 and between ultrasonography and cholangiography were not significant. Variations in the anatomy of the bile duct were observed in 21 patients in group 1 by laparoscopic ultrasonography and in 20 by intraoperative cholangiography. In group 2, 64 variations were demonstrated in 50 individuals by ultrasonography and 61 variations in 47 patients by cholangiography. Vascular variations were seen with ultrasonography in 22 and 24 patients in groups 1 and 2 respectively. In conclusion, laparoscopic ultrasonography (with either probe) proved as accurate as intraoperative cholangiography in detecting bile duct stones, and the specialized probe detected significantly more variations of the bile duct than the adapted probe.

Laparoscopic ultrasonography as compared with static or dynamic cholangiography at laparoscopic cholecystectomy. A prospective multicenter trial

We compared laparoscopic ultrasonography (LICU) with static (S) or dynamic (D) cholangiography (IOC) for assessment of duct anatomy an calculi in 209 patients. LICU visualized ducts in 88% compared with 93% for IOC (P = 0.046). Nineteen patients (9%) had stones: 17 were found by LICU (89%) and 10 (53%) by IOC (P = 0.032). Time to perform LICU (7 +/- 3 min) was less than IOC (13 +/- 6 min) (P < 0.0001). Time to perform SIOC (12 +/- 5 min) and DIOC (14 +/- 6 min) did not differ (P = 0.48), nor did these tests differ in accuracy. LICU provided useful anatomical information but IOC better defined anatomic anomalies. LICU required less time but was less reliable at defining anatomy and complete duct visualization. LICU was more sensitive for stones. SIOC and DIOC did not differ objectively. LICU and IOC are complementary.