Surgical outcomes research--a new paradigm for clinical research?

OBJECTIVE: To define outcomes research in terms of a paradigm, grouping six existing research methodologies. BACKGROUND: Although outcomes research is becoming an increasingly popular area in clinical research, an accepted definition is difficult to find. The term 'outcomes research' is often used in the context of a research methodology. METHODS: Topics in dinical research which have been termed 'outcomes research' are discussed including: databases, quality of life studies, effectiveness studies, economic evaluations, small-area rate variation analysis and volume outcome studies, as well as practice guideline development. RESULTS: Outcomes research is not a research methodology in its own right, but a paradigm which groups existing methodologies, providing a structured approach to evaluating the outcomes which are most important to patients, society and those who pay for health care.

The association between tamoxifen and the development of hepatocellular carcinoma: case report and literature review.

Tamoxifen has become one of the most widely used drugs in the treatment of breast cancer, and concerns about its long-term safety and efficacy are being raised. Investigations in rats have suggested an association between the administration of tamoxifen and the development of hepatocellular carcinoma. However, no studies to date have demonstrated an increased incidence of hepatocellular carcinoma in women treated with tamoxifen. In the case reported, a 56-year-old woman presented with hepatocellular tumours after 6 years of tamoxifen therapy for breast cancer. The patient had no other risk factors for the development of hepatocellular carcinoma. She underwent successful resection of the lesions, and subsequent pathological studies confirmed hepatocellular carcinoma with a trabecular growth pattern similar to the histologic pattern seen in tamoxifen-induced hepatocellular carcinoma occurring in rat models.

Laparoscopic cryosurgery for hepatic tumors. Experimental observations and a case report.

BACKGROUND: Hepatic cryosurgery has been shown to be a safe technique that may be well suited to a laparoscopic approach. METHODS: The technical feasibility and safety of laparoscopic cryosurgery was explored first in a pig model. Thereafter we performed the first successful case of laparoscopic hepatic cryosurgery at our institution. RESULTS: In the animal model, we found that it is possible to safely identify, target, and cryoablate specific lesions in the liver. Temperature in the peritoneal cavity remained above 35 degrees C, and pathologic examination of the abdominal wall around the cryoprobe site revealed no damage. We also successfully treated a 62-year-old man with a metastatic colorectal carcinoma deep in the right lobe of the liver with laparoscopic cryosurgery using a transpleural approach. CONCLUSION: We conclude that laparoscopic cryosurgery is feasible for lesions anywhere in the liver. For lesions high on the dome of the liver, a transpleural approach may provide better access.

Long-term survival after hepatic cryosurgery versus surgical resection for metastatic colorectal carcinoma: a critical review of the literature.

OBJECTIVE: To critically assess the evidence for long-term survival after hepatic resection and hepatic cryosurgery for metastatic colorectal cancer. The purpose of this review is to determine if a randomized controlled trial comparing these two treatment modalities is justified. DATA SOURCES: A review of the medical literature from 1973 to 1995 using the MEDLINE and CANCERLIT databases. References were also retrieved from the bibliographies of identified articles and from experts in the field of hepatobiliary and pancreatic surgery. STUDY SELECTION: One hundred and seventy-eight studies were reviewed. Studies presenting original data on the results of hepatic resection or cryotherapy for colorectal liver metastases were selected. Studies were excluded if they did not present survival data longer than 2 years. Studies pertaining to resection for fewer than 60 patients with colorectal metastases to the liver were excluded. DATA EXTRACTION: Data forms were designed before studies were examined in detail. All studies that met the inclusion and exclusion criteria were reviewed and the identified data extracted and tabulated. DATA SYNTHESIS: No controlled studies were identified, only case series. Four reports on hepatic cryosurgery and 9 on hepatic resection met the study criteria. The cryosurgery studies were methodologically poor; the resection studies were larger and more methodologically sound. The median follow-up for cryosurgery ranged from 12 to 28.8 months, that for resection 21 to 69 months. There is clear evidence that hepatic cryosurgery has a role in the management of selected patients with colorectal metastases to the liver. However, valid conclusions cannot be made about the 5-year survival rate. The results of the studies on hepatic resection in patients with colorectal metastases to the liver have greater validity and consistency, with 5-year survival rates of 20% to 40%. CONCLUSIONS: Although hepatic cryosurgery offers some unequivocal and other potential advantages over surgical resection for colorectal metastases to the liver, the published data do not support its use in patients with resectable disease outside a clinical trial, and do not yet justify a randomized trial. A study that collects prospective data on 2 groups of patients (resectable v. unresectable) who differ only in the anatomic location of their metastases within the liver is needed.

Laparoscopic vs. open intraoperative ultrasound examination of the liver: A controlled study.

A prospective study was undertaken to determine whether the use of laparoscopy plus laparoscopic ultrasound examination can avoid unnecessary laparotomy, without missing potentially curable disease, in patients scheduled for curative liver surgery. Thirty-one consecutive patients who underwent surgery for planned curative liver surgery were prospectively evaluated by means of both laparoscopy plus laparoscopic ultrasound and laparotomy with intraoperative ultrasound. Laparoscopic ultrasound examination of the liver could not be performed in two patients, and in two other patients only partial examinations were possible because of dense adhesions. All patients underwent laparotomy with intraoperative ultrasound. A total of 50 malignant lesions were identified by laparoscopic ultrasound. All of these lesions were confirmed to be malignant at laparotomy with intraoperative ultrasound, that is, there were no false positive results. An additional four malignant lesions in four patients were not seen at laparoscopic ultrasound examination but were identified at laparotomy with intraoperative ultrasound (sensitivity 93%, specificity 100%, positive predictive value 100%, negative predictive value 85%). Based on the laparoscopic ultrasound findings, nontherapeutic laparotomy could have been avoided in 10% of our patients. Laparoscopy with laparoscopic ultrasound is a promising technology that may allow some patients to avoid a nontherapeutic laparotomy without significant risk of missing potentially curable disease.

Management of cystic lesions of the tail of the pancreas.

OBJECTIVE: To emphasize that although cystic pancreatic neoplasms are stated to make up only 10% of pancreatic cysts, this number may be significantly higher if patients who are misdiagnosed with pseudocysts are considered. DESIGN: A small case series. SETTING: A tertiary-care centre. PATIENTS: A consecutive sample of three patients with cystic lesions of the tail of the pancreas seen between 1992 and 1994. All three were women ranging in age from 28 to 42 years. Two had been treated previously for pancreatic pseudocysts by cystenterostomy. None had a history of pancreatitis or alcohol abuse, and gallstones were not present on ultrasonography. INTERVENTIONS: Distal pancreactectomy and splenectomy. RESULTS: The excised specimens from the two patients treated initially elsewhere revealed mucinous cystadenoma with atypia in one and mucinous cystadenocarcinoma with invasion into stomach in the other. In the third patient, a cystic neuroendocrine tumour and two other intrapancreatic nodules of neuroendocrine tumour were found on pathological examination. CONCLUSIONS: Pancreatic neoplasms may be misdiagnosed as pancreatic pseudocysts. In patients without a history or risk factors for pancreatitis, a cystic pancreatic mass is not necessarily a pseudocyst, and such patients should be considered for pancreatic resection.