Preoperative Imaging Methods Research Articles

Intraoperative ultrasonography and the detection of liver metastases in patients with colorectal cancer

A total of 213 patients with carcinoma of the colon and rectum were examined to detect liver metastases. The study compared preoperative ultrasonography and inspection and palpation of the liver during surgery with intraoperative ultrasonography. Preoperative ultrasonography, inspection and palpation identified 238 metastases in 42 patients. Intraoperative ultrasonography detected 116 previously unrecognized metastatic tumours during 40 surgical procedures (P less than 0.01). High resolution intraoperative ultrasonography is safe and more accurate than preoperative imaging and surgical exploratory methods. The examination is simple to perform and success appears to be related to careful attention to detail.

Accuracy of preoperative imaging methods in a retrospective series of 14 patients with operated intraductal papillary mucinous tumors of the pancreas

Accuracy of preoperative imaging methods for the diagnosis of intraductal papillary mucinous tumor of the pancreas (IPMT) is not well known. To compare diagnostic accuracy of various preoperative imaging methods with pathology data following surgical resection. Fourteen consecutive patients underwent pancreatic surgical resection for IPMT between January 1988 and May 2002. Imaging methods included endoscopic retrograde cholangiopancreatography and/or magnetic resonance cholangiopancreatography and/or endoscopic ultrasonography. Results of preoperative morphological examinations were compared with histopathological findings from surgical specimens. IPMT was located to the pancreatic head or body in 72% of patients and involved the main pancreatic duct (MPD) in 79% of cases Carcinoma was diagnosed in 35% of the cases. Sensitivity of imaging methods varied from 64 to 80% to accurately locate the tumor and from 73 to 80% in distinguishing between types involving the MPD or the accessory ducts. Planned surgical resection based on preoperative imagery correlated with final surgery in 57% of the patients. Histological study of whole pancreas specimens revealed lesions in undilated ducts, and also dilated ducts without histological lesions. The sensitivity of preoperative imaging methods is moderate in defining intraductal extension of IPMT. Duct dilatation is not predictive of histological involvement by tumors and ducts may be pathological without dilatation.

Coronary Reconstructive Surgery versus Coronary Artery Bypass Grafting - A Documentation Gap

Over the last years, there has been a clear trend that an increasing number of patients are admitted for CABG with advanced disease, complex pathomorphological alterations and impaired left ventricular function. The necessity of performing extensive reconstructive coronary surgery rather than coronary bypass grafting, in its original sense, is not appropriately documented by the current version of the German Documentation System for Cardiac Surgery, nor in other national and international documentation systems. 5821 consecutive, unselected patients underwent isolated CABG from 7/1995 through 12/2003 at a single institution. A closing date follow-up procedure up to 8 years postoperatively was performed with a completeness of 98.8%. The need for reconstructive surgery in terms of extended anastomoses with or without coronary endarterectomy has doubled in our patients since 1995 and is steadily increasing with 15.7 % (n=102) of these patients requiring such surgery in 2003. Current documentation does not allow any prediction of complex coronary morphology. The Kaplan-Meier survival curve reveals no substantial difference between patients with and without coronary reconstructive surgery up to 8 years after CABG. The increase of complexity in CABG procedures currently remains undetected, since preoperative imaging methods often fail to predict complex coronary morphology. Survival after coronary reconstructive surgery is comparable to that of "classical" CABG. Therefore, a standardized documentation is required to evaluate surgical results and to contribute to the improvement of medical decision-making which presupposes valid data.

Usefulness of intraoperative electrical subcortical mapping during surgery for low-grade gliomas located within eloquent brain regions: functional results in a consecutive series of 103 patients.

Although a growing number of authors currently advocate surgery to treat low-grade gliomas, controversy still persists, especially because of the risk of inducing neurological sequelae when the tumor is located within eloquent brain areas. Many researchers performing preoperative neurofunctional imaging and intraoperative electrophysiological methods have recently reported on the usefulness of cortical functional mapping. Despite the frequent involvement of subcortical structures by these gliomas, very few investigators have specifically raised the subject of fiber tracking. The authors in this report describe the importance of mapping cortical and subcortical functional regions by using intraoperative real-time direct electrical stimulations during resection of low-grade gliomas. Between 1996 and 2001, 103 patients harboring a corticosubcortical low-grade glioma in an eloquent area, with no or only mild deficit, had undergone surgery during which intraoperative electrical mapping of functional cortical sites and subcortical pathways was performed throughout the procedure. Both eloquent cortical areas and corresponding white fibers were systematically detected and preserved, thus defining the resection boundaries. Despite an 80% rate of immediate postoperative neurological worsening, 94% of patients recovered their preoperative status within 3 months--10% even improved--and then returned to a normal socioprofessional life. Eighty percent of resections were classified as total or subtotal based on control magnetic resonance images. The use of functional mapping of the white matter together with cortical mapping allowed the authors to optimize the benefit/risk ratio of surgery of low-grade glioma invading eloquent regions. Given that preoperative fiber tracking with the aid of neuroimaging is not yet validated, we used intraoperative real-time cortical and subcortical stimulations as a valuable adjunct to the other mapping methods.

Use of diagnostic laparoscopy and laparoscopic ultrasound in the management of upper gastrointestinal malignancy

Background: Despite various preoperative imaging methods, unnecessary laparotomy is still quite common in upper gastrointestinal surgery. There have been some studies demonstrating the use of diagnostic laparoscopy and laparoscopic ultrasound in the detection of small peritoneal seedling and vascular encasement of major vessels respectively, and these are the findings often inadequately assessed by preoperative imaging.Objective: This is a study to evaluate the use of diagnostic laparoscopy and selective laparoscopic ultrasound in the management of upper gastrointestinal malignancy.Method: A prospective study was carried out during the period from January 1996 to December 1997. Patients with upper gastrointestinal malignancy underwent diagnostic laparoscopy and selective laparoscopic ultrasound before resection. The role of laparoscopic staging was evaluated according to the number of patients who avoided unnecessary laparotomy.Results: There were 159 patients of mean age 62.8 years diagnosed with upper gastrointestinal tumours during the study period. These patients had various upper gastrointestinal malignancies: gastric carcinoma (89), oesophageal carcinoma (27), hepatobiliary malignancy (26), peri‐ampullary carcinoma (15) and small bowel tumour (2). Routine diagnostic laparoscopy and selective laparoscopic ultrasound were carried out for these patients unless there were contraindications such as a history of previous upper gastrointestinal surgery or the patient required palliative procedure irrespective of resectability. There were 106 diagnostic laparoscopies and 42 laparoscopic ultrasounds performed. Unnecessary operations were avoided in 32 patients (30%) due to either diffuse carcinomatosis or locally advanced tumour with encasement of major vessels. The role of laparoscopic staging in avoiding unnecessary surgery was particularly pronounced in peri‐ampullary carcinoma (46%) and hepatobiliary malignancy (38%).Conclusion: In summary, diagnostic laparoscopy and selective laparoscopic ultrasound are useful in avoiding unnecessary laparotomy particularly in hepatobiliary and peri‐ampullary malignancy.

IMAGING OF HEPATIC TRANSPLANTATION

This article provides a clinical overview of liver transplantation. Preoperative radiologic imaging methods are discussed. Relevant surgical anatomy is illustrated, including vascular and biliary anastomoses. The radiologic features of vascular complications in liver transplantation are also reviewed.

A CASE OF SCHWANNOMA ARISING IN THE MESENTERY OF THE SMALL INTESTINE

An extremely rare case of schwannoma arising in the mesentery of the small intestine is described here. An asymptomatic 65-year-old woman was pointed out having a tumor by abdominal ultrasonography on medical checkup at another hospital. The patient was referred to the hospital. Preoperative imaging methods including abdominal ultrasonography, CT, abdominal angiography revealed a relatively discrete tumor with a cystic change in its center in the jejunal mesentery. Under a most probable diagnosis of schwannoma, the tumor was extirpated. The extripated tumor was 65×50×45mm in size, elastic hard, and 85g in weight. There were a yellowish white solid portion in the capsule with a thickness of three milimeter and a cystic portion in the center. Histopathologically it was schwannoma of mixed type of Antoni type A and B. Mesenteric tumors often present difficulty in preoperative diagnosis. We should entertain the disease as a possible diagnosis in operating such tumors, if a cystic change in the center of the tumor on imagings is found out like in this case.

Imaging of gastrointestinal neuroendocrine tumors

Gastrointestinal neuroendocrine tumors are rare neoplasms that cause classic clinical syndromes because of the excess secretion of specific gastrointestinal hormones. The two most important tumors clinically are insulinomas and gastrinomas. The clinical management of patients with these disorders usually involves the localization and surgical removal of the responsible tumor. Many radiological techniques can be used for tumor localization, including preoperative and intraoperative ultrasound, endoscopic ultrasound, CT, MRI, radionuclide scanning, angiography, and venous sampling. However, there are conflicting claims as to the relative accuracy of these procedures, and many of these investigations are difficult to justify because of their high cost, degree of invasiveness, or lack of precise anatomic information that is obtained. If surgical resection of a neuroendocrine tumor is planned, intraoperative sonography should always be used to detect occult nonpalpable tumors and to discern the relationship of the tumor to vital adjacent pancreatic ductal anatomy. The choice of preoperative imaging is more controversial, and depends on the clinical problem, local expertise, and availability of imaging techniques. Sonography and contrast-enhanced helical CT are the most commonly used preoperative imaging methods, because of their relatively low cost and widespread availability. Radionuclide scanning with a somatostatin analogue, which is a relatively new procedure, may be valuable in patients with symptoms of tumor recurrence.

A CASE OF RETROPERITONEAL MALIGNANT FIBROUS HISTIOCYTOMA

This paper presents a recent experience with a case of retroperitoneal malignant fibrous histiocytoma. A 62-year-old woman was seen at the hospital because of an abdominal tumor.A 12×10cm tumor mass extending from the left hypochondrium to left lateral region was palpated.Abdominal ultrasonography and CT visualizied a well defined oval tumor. Angiography confirmed a serpentine irregular vascular figure.It was diagnosed as sarcoma arising in the retroperitoneum and the tumor was removed.The well encapsulated tumor was 11.5×10.5×8.5cm in size and 560g in weight.The cut surface was solid, scattered with cysts with less than 1cm in size, and partially included hemorrhagic portions. Histological diagnosis of malignant fibrous hystiocytoma was made.No radiotherapy or chemotherapy was conducted postoperatively. There has been no recurrence, as of one year and 9 months after the operation.As this disease is considered to arize in the retroperitoneum in a relatively high frequency, further such cases may be increasingly reported. Preoperative imaging methods present difficulties in definite diagnosis of this disease. Good prognosis can not be expected for the advanced tumor. Early surgical removal of the tumor would be the best and only therapy.

鼓室型グロムス腫よう症例 術前の画像診断を中心に

The patient was 67-year-old female who complained of pulsatile tinnitus in the right ear. Otoscopy revealed a reddish mass that extended to the annulus.CT, MRI and angiography localized it in the middle ear cavity and distinguished it from the jugular bulb. The tumor was completely resected by posterior hypotympanotomy after embolization of the superior tympanic artery. Absence of tumor recurrence was con-firmed 8 months after surgery. We discuss the benefits of preoperative diagnostic imaging methods.

Detection of hepatocellular carcinoma: comparison of CT during arterial portography with CT after intraarterial injection of iodized oil.

Fourteen patients with hepatocellular carcinoma (HCC) were examined with computed tomography (CT) during arterial portography (CTAP) and with CT after intraarterial injection of iodized oil. The detectability of main lesions and associated daughter nodules or intrahepatic metastases was assessed. Hepatic resection was subsequently performed in all 14 patients. The results of the imaging studies were compared with the surgical and pathologic findings by means of a lesion-by-lesion analysis. A total of 34 masses were identified in the resected specimens: 18 main tumor masses and 16 intrahepatic metastases. For CTAP, the detection rate of main tumors was 94%; for iodized-oil CT, 82%. However, the daughter-nodule detection rates for both techniques were poor-only 38% detected for CTAP and 50% for iodized-oil CT. Although these two techniques remain important preoperative imaging methods in patients with HCC, the results of this study suggest that small daughter nodules (less than 5 mm in diameter) may go undetected with both techniques.

Intraoperative ultrasound in detecting hepatic metastases.

As a new screening procedure, intraoperative ultrasonography using high-resolution real-time instruments was used routinely in 84 colorectal cancer operations to scan the entire liver for liver metastases. In 10 operations (11.9%), intraoperative ultrasonography identified 14 previously unrecognized metastatic tumors, all of which were less than 2 cm in size and were nonpalpable. The sensitivity of this technique in detecting metastatic liver lesions (97.8%) was significantly superior (p < 0.01) to that of preoperative ultrasound (41.3%), computed tomography (47.8%), and surgical exploration (58.7%), while the specificity of each test was comparable (approximately 90%). High-resolution intraoperative ultrasonography is safe, simple to perform and more accurate than preoperative imaging and surgical exploratory methods. Therefore its use is encouraged during colorectal cancer surgery for screening of liver metastases.

The detection of gastric and esophageal tumor extension by high-resolution ultrasound during surgery.

AbstractHigh‐resolution ultrasound with 7.5‐MHz instruments was employed to detect tumor extension during 30 gastric and 25 esophageal cancer operations. With 5 echo layers, which corresponded to histologie structures of the stomach wall, operative ultrasound diagnosed intramural tumor spread more accurately than operative palpation. Thirteen of 14 early gastric cancers including 8 nonpalpable cancers were precisely localized by operative ultrasonography. In addition, lateral extension of tumor along the stomach wall was correctly diagnosed by operative ultrasound in 26 of 30 cancers, while palpation was correct in 14 of 30 cancers. For esophageal cancer, extramural local invasion, particularly to vessels, was accurately detected by operative ultrasound. Three of 25 esophageal cancers had histological invasion of the aorta. Preoperative imaging methods showed 1 false‐negative and 2 false‐positive results in determining the aortic invasion. Operative ultrasound had no false results. Lymph nodes that were unrecognized at preoperative studies, nodes that were nonpalpable prior to tissue dissection, and nodes as small as 3 mm in size could be depicted by ultrasonography during gastroesophageal operations. The present results indicate that high‐resolution operative ultrasound may be a valuable technique for the detection of gastric and esophageal cancer extension during surgery.