Preoperative evaluation of patients for liver resection. Appropriate CT imaging

Colorectal Cancer:: Imaging Conundrums

Progressive technological advancements in imaging have significantly improved the preoperative sensitivity for the detection of very small foci of regionally- or hematogenously-metastatic colorectal cancer. Unfortunately, this information has not translated to continued linear gains in patient survival, and might even result in the false-positive upstaging of some cases: these are two conundrums in the imaging of colorectal cancer. Both conundrums might be resolved by the widespread use of real-time imaging guidance during operative procedures. This might open the way for the widespread use of fluorodeoxyglucose PET/CT for the initial staging of patients with colorectal cancer.

Hepatectomias: análise crítica retrospectiva de 21 casos

OBJETIVO: Analisar os principais aspectos técnicos e clínicos referentes às ressecções hepáticas realizadas em um período de cinco anos (1994 a 1998). MÉTODO: Estudo retrospectivo de 21 ressecções hepáticas, com ênfase no tipo de ressecção utilizado, o preparo pré-operatório e as complicações do período pós-operatório. Ademais, estabelecer correlações com os dados clínicos e epidemiológicos, bem como os exames complementares mais solicitados, em especial, o exame histopatológico. RESULTADOS: Foram realizadas oito ressecções locais atípicas, quatro segmentectomias, quatro hepatectomias esquerdas, duas hepatectomias direitas, uma lobectomia esquerda, uma trissegmentectomia esquerda e uma trissegmentectomia direita. As ressecções foram indicadas para tratamento de tumores malignos primários do fígado em nove pacientes; tumores benignos em seis pacientes; miscelânea em três pacientes; metástases hepáticas em dois e tumor de via biliar em um paciente. As complicações pós-operatórias ocorreram em sete pacientes (33%), sendo as mais freqüentes o abscesso subfrênico e peritonite e a mortalidade operatória foi de 9,5%. CONCLUSÕES: A cirurgia hepática tem se tornado cada vez mais factível e as complicações pós-operatórias, sob maior controle clínico, têm diminuído bastante a mortalidade.

A critical appraisal of laparoscopic staging in hepatobiliary and pancreatic malignancy

Prognosis for patients with hepatobiliary and pancreatic cancers is dismal. Surgery is the best therapeutic option for those with tumors which have not yet metastasized. Standard radiologic tests such as computed tomography (CT) scan and trans-abdominal ultrasound are useful in identifying patients for whom an attempt at resection would be futile. Staging laparoscopy with laparoscopic ultrasound allows greater precision in identifying those for whom resection would be helpful with less morbidity than an open exploration. Metastatic disease can be identified more precisely than with radiologic tests and can be characterized by biopsy techniques. Palliative procedures are now being performed laparoscopically with low morbidity and short hospital stays. The use of laparoscopy prior to open exploration for patients with hepatobiliary and pancreatic tumors is advantageous.

Preoperative staging of rectal carcinoma

BACKGROUND

The development of treatment modalities for rectal cancer, including local excision, total mesorectal excision and preoperative radiotherapy, has increased the importance of accurate preoperative staging to allow the optimum treatment to be selected.

METHODS

A literature review was undertaken of methods of preoperative staging of rectal carcinoma and the evidence for each was evaluated critically.

RESULTS

Clinical assessment of rectal carcinoma may give an indication of fixity but is not accurate for staging. Endoanal ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), radioimmunoscintigraphy and positron emission tomography have all been used for staging. The extent of tumour spread through the bowel wall (T stage) is most accurately assessed by endoanal ultrasonography, although this technique is poor at assessing tumour extension into adjacent organs for which both CT and MRI are more accurate. No method accurately determines lymph node involvement, but endoanal ultrasonography is the best available. Liver metastases may be assessed by abdominal ultrasonography, CT, MRI and CT portography (with increasing sensitivity and cost in that order).

CONCLUSION

Endoanal ultrasonography is the most effective method of local tumour staging, with the addition of either CT or MRI if adjacent organ involvement is suspected. Abdominal ultrasonography or CT is recommended for routine preoperative assessment of the liver.

Intraoperative determinants of unresectability for patients with colorectal hepatic metastases

BACKGROUND

Intrahepatic and extrahepatic factors are utilized by the surgeon in the decision-making process for the performance of hepatic resection for patients with colorectal metastases. Accurate preoperative and intraoperative staging are mandatory to avoid unnecessary surgery. In this report the intraoperative determinants of hepatic unresectability were evaluated.

METHODS

This was a retrospective review of medical records from January 1985 to March 1996 of 62 patients with colorectal hepatic metastases who at the time of exploratory laparotomy were deemed to have unresectable disease based on intrahepatic or extrahepatic factors. The stage of the primary tumor, disease free interval, preoperative carcinoembryonic antigen, computed tomography portography, intraoperative ultrasound, and assessment of intrahepatic and extrahepatic tumor extension were evaluated.

RESULTS

Intraoperative determination of the extent of required hepatic resection, including trisegmentectomy (9 patients; 15%) and total hepatectomy (10 patients; 16%), accounted for the majority of unresectable patients. Patients with > 4 metastases (8 patients; 13%) and satellitosis (6 patients; 10%) accounted for 23% of unresectable patients. Four patients had extensive nonmalignant hepatic parenchymal disease precluding resection. Thorough abdominal exploration revealed extrahepatic disease in 13 of 62 patients (21%). Routine periportal/celiac lymph node biopsies revealed metastases in an additional 12 patients (19%), 7 of whom (11%) had only periportal/celiac lymph node metastases.

CONCLUSIONS

A meticulous abdominal exploration prior to hepatic resection for patients with colorectal metastases is essential to identify those patients with extrahepatic disease. Periportal and celiac lymph nodes commonly are involved by tumor. Therefore, routine periportal/celiac lymph node biopsies should be performed in the absence of other extrahepatic disease.

Accuracy of computed tomography in determining resectability for locally advanced primary or recurrent colorectal cancers

AIM

To determine the accuracy of computed axial tomography (CT) in determining tumor resectability in patients with locally advanced primary (T4) or locally recurrent colorectal cancer.

METHODS

Computed tomography scans of 84 patients with "resectable" locally advanced primary rectal cancer (n = 12) or recurrent colorectal cancer (n = 72) were compared with the operative findings to assess the accuracy of abdominal and pelvic CT in determining extent of disease and resectability.

RESULTS

At surgery, disease was confined to the pelvis in 63 patients, the abdomen in 7, and involved both the pelvis and abdomen in 14. Computed tomography correctly identified these anatomic sites of tumor in 87% of patients, with 89% and 80% accuracies for pelvic and abdominal disease, respectively. Tumor resection was performed in 71 patients (85%), but was not in 13 patients because of locally unresectable disease in 8 and metastatic disease in 5. The accuracy of predicting tumor-related operability was 85%. With regard to adjacent organ resection, CT was accurate in determining the need for sacrectomy or hysterectomy, but overestimated the need for urinary organ resection. Based on histological examination of resection margins, CT correctly staged (n = 45) or overstaged (n = 9) 54 patients (64%) and understaged the remaining 30. The ability of CT to preoperatively predict a locally advanced tumor after preoperative radiation therapy as not being fixed was 30%, fixed but resectable 75%, and fixed but not resectable 25%.

CONCLUSIONS

Computed tomography is generally reliable at identifying disease as being confined to one region, and for predicting the need for adjacent organ resection. It is less discriminating for predicting local tumor resectability.

Management strategies for colorectal liver metastases--Part I

Colorectal cancer is a common malignancy and the incidence of this disease is increasing. Approximately 50% of patients with colorectal cancer die from recurrent disease following an apparently curative resection of the primary tumour and the liver is the most frequent site of relapse. Although only a small proportion of patients will benefit from resection of liver metastases, this form of treatment offers the only possibility of cure. In selected patients, 5-year survival rates of 25-35% may be achieved following liver resection. A poor prognosis after resection of hepatic metastases is likely when there are more than three metastatic deposits, involved resection margins often as a result of ¿wedge' resections, when there is extrahepatic disease, or when there is nodal involvement at the primary tumour site. Regional hepatic artery infusion chemotherapy may provide palliation and possibly even prolongation of survival for some patients with unresectable metastases. Cytoreductive techniques may also provide palliation in selected patients with hepatic metastases unsuitable for resection; cryotherapy is the most promising of these methods.

Staging laparoscopy with laparoscopic ultrasonography: optimizing resectability in hepatobiliary and pancreatic malignancy

BACKGROUND

Open laparotomy has traditionally been required to stage hepatobiliary and pancreatic (HBP) cancers accurately. For unresectable patients, costs and morbidity have been high. Today, laparoscopy alone or combined with laparoscopic ultrasonography (LUS) is being examined for its value in defining the extent of malignancy.

STUDY DESIGN

We have analyzed the effect of routine implementation of this new staging technique in our HBP center. Staging laparoscopy (SL) with LUS was performed in 50 consecutive patients with HBP malignancies. All patients were considered to have resectable tumors as determined by traditional preoperative staging modalities. Primary tumors were located in the liver (n = 7), biliary tract (n = 11), or pancreas (n = 32). An average of 2.7 preoperative studies per patient were performed prior to SL-LUS.

RESULTS

Staging laparoscopy with laparoscopic ultrasonography predicted resectable tumors in 28 patients (56%). At laparotomy, 26 of 28 were actually resectable: the false-negative rate was 4%. Staging laparoscopy with laparoscopic ultrasonography indicated unresectability in 22 patients (44%). Staging laparoscopy alone demonstrated previously unrecognized occult metastases in 11 patients (22%). In 11 other patients (22%) in whom SL alone was negative, LUS established unresectability from vascular invasion (n = 5), lymph node metastases (n = 5), or intraparenchymal hepatic tumor (n = 1). All cases of unresectability due to vascular invasion were validated by laparotomy. Five of six lymph node or hepatic metastases were proved histologically by LUS-guided needle biopsy rather than laparotomy.

CONCLUSIONS

Unnecessary laparotomy can be safely avoided by SL-LUS in many patients with HPB malignancies, reducing costs and morbidity.

Role of computed tomographic arterial portography and intraoperative ultrasound in the evaluation of patients for resectability of hepatic lesions

Computed tomographic arterial portography (CTAP) has been shown to be the most sensitive preoperative test for determining resectability of hepatic lesions but we have shown it to have low specificity. Intraoperative ultrasound (IOUS) evaluation of the liver has also been proposed as an accurate means of assessing resectability. We sought to compare the effectiveness of the two modalities. Fifty-six patients who had been deemed candidates for liver resection based on CTAP findings underwent systematic exploration, liver mobilization, and IOUS examination. Ultrasound findings were compared with results of CTAP. In 46 patients the IOUS findings were in complete agreement with those of CTAP. In 10 patients CTAP lesions could not be verified by IOUS and these patients did not undergo resection. Follow-up of these 10 patients revealed eight who did not have progression of malignancy at the CTAP-predicted site (CTAP false positive). Two patients did have progression at a CTAP-positive IOUS-negative site (IOUS false negative). Sensitivity for CTAP and IOUS was 100% and 96%, respectively. Specificity for IOUS was 100%. These findings demonstrate the high sensitivity of CTAP and the high sensitivity and specificity of IOUS. CTAP may "overcall" hepatic lesions but IOUS can correctly identify these false positives in most instances. Because CTAP is useful for determining which patients might benefit from surgical exploration, we conclude that the two modalities are complementary for the assessment of resectability of hepatic lesions. The false positive rate for CTAP implies that caution must be used when declining to operate on patients on the basis of this test.

CT during arterial portography

CT during arterial portography (CTAP) is based on portal enhancement of the liver by infusion of contrast material through the superior mesenteric or splenic artery. This technique provides high degrees of enhancement of the portal vein and intrahepatic vessels, allowing reliable segmental localisation of tumours and accurate assessment of relationships between tumours and intrahepatic vessels. Because of its invasiveness, CTAP must be limited to patients for whom non-invasive preoperative imaging suggests resectable tumour. In the majority of cases, CTAP is performed in patients with hepatic metastases from colorectal cancer, but other types of hepatic tumour (either primary or secondary) and pancreatic tumour may be an indication for CTAP. Visualisation of non-tumorous perfusion defects is a limitation of this technique, but such defects have been well described and have characteristic locations and appearance. In difficult cases, correlation with sonographic, CT and MRI findings helps characterise portal perfusion defects. CTAP is the most sensitive technique for the detection of intrahepatic tumours, and the recent use of spiral technology shows promise in the performance of CTAP. CTAP data can be viewed as multiplanar and three-dimensional reconstructions that allow preoperative planning of the extent of resection and determination of the volume of the remaining liver after resection.

Malignant liver lesions: comparison of spiral CT arterial portography and MR imaging for diagnostic accuracy, cost, and effect on patient management

We compared two imaging techniques, spiral CT arterial portography (CTAP) and MR imaging, for diagnostic accuracy, procedural cost, and effect on management of 26 patients referred for hepatic surgery for suspected limited malignant liver disease. CTAP and MR imaging were done within a 1-week period (19 within 24 hours); the results of the studies were interpreted prospectively by separate reviewers. Surgical data were evaluated in conjunction with imaging data in 10 patients. Lesion detection and segmental involvement were determined and sensitivity and specificity were calculated. Procedural cost was determined from hospital billing codes. Effect on patient management was determined by the referring oncologic surgeon. CTAP and MR imaging showed 185 and 176 true-positive malignant lesions, 15 and zero false-positive malignant lesions, zero and 18 true-negative malignant lesions, and 13 and 22 false-negative malignant lesions, respectively. CTAP and MR imaging showed 107 and 105 true-positive segments, 11 and zero false-positive segments, 80 and 91 true-negative segments, and four and six false-negative segments, respectively. There was a significant difference in specificity of segmental involvement between MR imaging (1.0 +/- 0) compared with CTAP (0.88 +/- 0.05), P = .03. Total procedural cost was $3,499 for CTAP and $1,224 for MR imaging. CTAP findings did not change patient management over MR imaging findings in any patient, whereas MR imaging findings resulted in a change in patient management over CTAP findings in seven patients (P = .015). The results of our study suggest that MR imaging has higher diagnostic accuracy and greater effect on patient management than CTAP does and is 64% less expensive.

Application of three-dimensional spiral computed tomographic angiography prior to hepatectomy for hepatocellular carcinoma

A newly developed method of spiral computed tomography (CT) angiography was employed for 19 consecutive hepatocellular carcinoma (HCC) patients who underwent hepatectomy. Fine images of the intrahepatic vascular structure, portal venous branches and hepatic veins, and HCC nodules were obtained in 16 patients. A more accurate and easier understanding of the relationship between the intrahepatic vascular structure and the HCC nodules was provided by this spiral CT angiography compared with any other imaging modality.

Superior staging of liver tumors with laparoscopy and laparoscopic ultrasound

OBJECTIVE

The authors describe the technique of staging laparoscopy with laparoscopic contact ultrasonography in the preoperative assessment of patients with liver tumors, and assess its impact on the selection of patients for hepatic resection with curative intent.

SUMMARY BACKGROUND DATA

Laparoscopy may be useful in the selection of patients with a variety of intra-abdominal malignancies for operative intervention. Laparoscopic ultrasonography is a new technique that combines the principles of high resolution intraoperative contact ultrasound with those of the laparoscopic examination, and thus, allows the laparoscopist to perform detailed assessment of the liver.

METHODS

This study analyzes a cohort of 50 consecutive patients who were diagnosed as having potentially resectable liver tumors, and in whom staging laparoscopy was successfully undertaken. Laparoscopic ultrasonography was performed in 43 patients, and the impact of the ensuing findings on the decision to proceed to operative assessment of resectability is examined. The resectability rate in those patients assessed laparoscopically and subsequently submitted to laparotomy is compared with a preceding group of patients in whom no laparoscopic assessment was performed.

RESULTS

Laparoscopy demonstrated factors precluding curative resection in 23 patients (46%). Laparoscopic ultrasonography identified liver tumors not visible during laparoscopy in 14 patients (33%), and provided staging information in addition to that derived from laparoscopy alone in 18/43 patients (42%). The resectability rate was significantly higher among those patients undergoing laparoscopic staging (93%) compared with those in whom operative assessment was undertaken without laparoscopy (58%).

CONCLUSIONS

Staging laparoscopy with laparoscopic ultrasonography optimizes patient selection for liver resection with curative intent.

Intrahepatic cholangiocarcinoma: findings on spiral CT during arterial portography

To attempt to determine the characteristic imaging features of intrahepatic cholangiocarcinoma on spiral CT during arterial portography (CTAP), spiral CTAP examinations of 17 patients with pathologically confirmed intrahepatic cholangiocarcinoma were reviewed in consensus by three radiologists. The diameter of the tumors ranged from 1 to 12 cm (mean diameter, 6.6 cm). All tumors (100%) were hypoattenuating masses on spiral CTAP. In 11 cases, the tumor was homogeneous in attenuation (65%). Tumor margins were smooth and regular in 11 cases (65%). Vascular invasion was found in 14 cases (82%). Intrahepatic bile duct dilatation was present in seven cases (41%). This review shows that intrahepatic cholangiocarcinoma is associated with a constellation of findings on spiral CTAP. The presence of a low attenuation homogeneous intrahepatic mass with vascular invasion and intrahepatic bile duct dilatation on spiral CTAP images should raise the possibility of intrahepatic cholangiocarcinoma. However, these findings can be associated with other types of primary and secondary malignant hepatic tumors.

Role of staging laparoscopy in the treatment of hepatic malignancy

Despite current radiologic imaging capabilities, 40% to 70% of patients with primary or metastatic hepatic malignancies are found to have unresectable disease at the time of laparotomy. The present study evaluates the use of laparoscopy in the staging of hepatic malignancy. Twenty-nine patients underwent staging laparoscopy prior to a planned laparotomy for resection of a hepatic malignancy that was deemed resectable by computed axial tomographic scan and ultrasonography. Twelve patients had primary hepatic malignancies, and 17 had metastatic malignancies. Laparoscopy demonstrated evidence of unresectability in 48% (14 of 29) of patients studied. Four patients had unsuspected cirrhosis, and 10 had unresectable or extrahepatic metastatic disease. Patients who underwent laparoscopy alone had shorter mean hospital lengths of stay than historical controls who underwent laparotomy alone. We conclude that diagnostic laparoscopy should precede laparotomy for planned resection of hepatic malignancies.