Intraoperative ultrasonography in detection of hepatic metastases from colorectal cancer

The value of preoperative computed tomography combined with ultrasound in the investigation of small indeterminate liver lesions in patients with colorectal cancer

Background Computed tomography (CT) is used routinely for the preoperative detection of colorectal cancer (CRC) metastases. When small indeterminate focal liver lesions are detected that are too small to characterize (TSTC) on CT, additional imaging is usually needed, resulting in a potential delay in obtaining a complete diagnostic work-up. Purpose To determine the diagnostic accuracy of ultrasound (US) of the liver performed in direct conjunction to CT in the preoperative investigation among patients with newly diagnosed CRC when indeterminate liver lesions were found on CT. Material and Methods Preoperative investigations with CT and consecutive US where CT had shown at least one focal liver lesion in 74 patients diagnosed with CRC between June 2009 and February 2012 were retrospectively reviewed. Either histopathological findings or a combination of imaging and clinical follow-up one to three years after surgery was used as the reference. Results Liver metastases were diagnosed with CT/US in 13 out of 74 patients (17.6%). In one patient, a liver cyst was preoperatively regarded as liver metastasis by a combined CT/US. The sensitivity and specificity for the CT with consecutive US procedure was 100% (13/13) and 98.4% (60/61). Conclusion US performed in conjunction with CT in patients with indeterminate focal liver lesions on CT is an accurate work-up for detection of liver metastases in patients with newly diagnosed CRC. Although our results are promising, they cannot be considered safely generalizable to all hospitals.

Randomized clinical trial of laparoscopic ultrasonography before laparoscopic colorectal cancer resection

BACKGROUND

Intraoperative ultrasonography during open surgery for colorectal cancer may be useful for the detection of unrecognized liver metastases. Laparoscopic ultrasonography (LUS) for the detection of unrecognized liver metastasis has not been studied in a randomized trial. This RCT tested the hypothesis that LUS would change the TNM stage and treatment strategy.

METHODS

Patients with colorectal cancer and no known metastases were randomized (1 : 1) to laparoscopic examination (control or laparoscopy plus LUS) in three Danish centres. Neither participants nor staff were blinded to the group assignment.

RESULTS

Three hundred patients were randomized, 150 in each group. After randomization, 43 patients were excluded, leaving 128 in the control group and 129 in the LUS group. Intraoperative T and N categories were not altered by LUS, but laparoscopy alone identified previously undetected M1 disease in one patient (0·8 per cent) in the control group and three (2·3 per cent) in the LUS group. In the latter group, LUS suggested that an additional six patients (4·7 per cent) had M1 disease with liver (4) or para-aortal lymph node (2) metastases. The change in treatment strategy was greater in the LUS than in the control group (7·8 (95 per cent c.i. 3·8 to 13·8) and 0·8 (0 to 4·2) per cent respectively; P = 0·010), but the suspected M1 disease was benign in half of the patients.

CONCLUSION

Routine LUS during resection of colorectal cancer is not recommended. Registration number: NCT02079389 (http://www.clinicaltrials.gov).

Intraoperative Ultrasound as a Screening Modality for the Detection of Liver Metastases during Resection of Primary Colorectal Cancer - A Systematic Review

Colorectal cancer (CRC) is one of the most common cancer diseases worldwide. One in 4 patients with CRC will have a disseminated disease at the time of diagnosis and often in the form of synchronous liver metastases. Studies suggest that up to 30% of patients have non-recognized hepatic metastases during primary surgery for CRC. Intraoperative ultrasonography examination (IOUS) of the liver to detect liver metastases was considered the gold standard during open CRC surgery. Today laparoscopic surgery is the standard procedure, but laparoscopic ultrasound examination (LUS) is not performed routinely. Aim To perform a systematic review of the test performance of IOUS and LUS regarding the detection of synchronous liver metastases in patients undergoing surgery for primary CRC. Method The literature was systematically reviewed using the search engines: PubMed, Cochrane, Embase and Google. 21 studies were included in the review and the key words: intraoperative ultrasound, laparoscopic ultrasound, staging colon and rectum cancer. Results Intraoperative ultrasound showed a higher sensitivity, specificity, positive predictive value and overall accuracy for the detection liver metastases during surgery for primary CRC, compared to preoperative imaging modalities (ultrasound, computed tomography (CT) and contrast-enhanced computed tomography (CE-CT)). LUS showed a higher detection rate for liver metastases compared to CT, CE-CT and magnetic resonance imaging (MRI). Conclusion This systematic review found that both IOUS and LUS had a higher detection rate regarding liver metastases during primary CRC surgery, especially liver metastases<10 mm in diameter, when compared to US, CT, CE-CT and MRI.

Is intra-operative ultrasound still useful for the detection of a hepatic tumour in the era of modern pre-operative imaging?

BACKGROUND

The current role of intra-operative ultrasound (IOUS) is questioned because of recent progress in medical imaging. The aim of the present study was to determine the accuracy of IOUS in the detection of a hepatic tumour (HT) compared with a pre-operative multi-detector computed tomography (MDCT) scan and magnetic resonance imaging (MRI).

METHODS

This retrospective study included 418 patients evaluated using an 8-slice MDCT scan (SCAN8), 64-slice MDCT scan (SCAN64) and MRI alone or combined with a computed tomography (CT) scan. The pathological result was used as a gold standard.

RESULTS

Correlation rates for the number of detected lesions compared with pathology results were 0.627 for SCAN8, 0.785 for SCAN64, 0.657 for MRI and 0.913 for IOUS. Compared with pathology, the rate of concordance was significantly higher with IOUS (0.871) than with SCAN8 (0.736; P=0.011), SCAN64 (0.792; P<0.001) and MRI (0.742; P<0.001). IOUS was responsible for a change in operative strategy in 16.5% of patients. Surgery was extended in 12.4%, limited in 1.7% and abandoned in 2.4%.

CONCLUSIONS

Compared with cross-sectional pre-operative imaging, IOUS is still superior for the detection of HT and the planning of surgery. IOUS remains recommended as a routine procedure in patients having a hepatic resection in the era of modern pre-operative imaging.

Current trends in staging rectal cancer

Management of rectal cancer has evolved over the years. In this condition preoperative investigations assist in deciding the optimal treatment. The relation of the tumor edge to the circumferential margin (CRM) is an important factor in deciding the need for neoadjuvant treatment and determines the prognosis. Those with threatened or involved margins are offered long course chemoradiation to enable R₀ surgical resection. Endoanal ultrasound (EUS) is useful for tumor (T) staging; hence EUS is a useful imaging modality for early rectal cancer. Magnetic resonance imaging (MRI) is useful for assessing the mesorectum and the mesorectal fascia which has useful prognostic significance and for early identification of local recurrence. Computerized tomography (CT) of the chest, abdomen and pelvis is used to rule out distant metastasis. Identification of the malignant nodes using EUS, CT and MRI is based on the size, morphology and internal characteristics but has drawbacks. Most of the common imaging techniques are suboptimal for imaging following chemoradiation as they struggle to differentiate fibrotic changes and tumor. In this situation, EUS and MRI may provide complementary information to decide further treatment. Functional imaging using positron emission tomography (PET) is useful, particularly PET/CT fusion scans to identify areas of the functionally hot spots. In the current state, imaging has enabled the multidisciplinary team of surgeons, oncologists, radiologists and pathologists to decide on the patient centered management of rectal cancer. In future, functional imaging may play an active role in identifying patients with lymph node metastasis and those with residual and recurrent disease following neoadjuvant chemoradiotherapy.

Preoperative investigations for metastatic staging of colon and rectal cancer across multiple centres--what is current practice?

OBJECTIVE

The optimal strategy for elective distant staging of colorectal carcinoma (CRC) has yet to be defined, with current guidelines based on small and limited series. One specific issue requiring review is the value of routine computerized tomographic (CT) chest examination. Also lacking is data on current routine clinical practice.

METHOD

A retrospective chart review of consecutive cases of elective surgery for CRC from five hospitals.

RESULTS

Two hundred and fifty-seven cases were reviewed, 128 colon and 129 rectal primaries. 164 (64%) of patients overall, ranging from 45% to 88% across the individual centres, had a preoperative serum CEA level performed. CT abdomen/pelvis was performed in 222 (86%) of cases, ranging from 69% to 98% per centre. CT chest was performed in 95 (37%) of cases, 47% of rectal vs 29% of colon cancers (P = 0.004). In 17 cases (18%) CT chest examinations revealed abnormalities suspicious for metastatic disease, leading to a change in management in six (35%) of these cases. Of the 17 cases with an abnormal CT chest, in only 5 of the 14 (36%) where carcinoembryonic antigen (CEA) levels were also recorded was this increased, and in only three (21%) was this markedly (> 10 microg/l) elevated.

CONCLUSIONS

Substantial variability exists in the preoperative evaluation of patients with CRC. Many patients do not have a CEA and/or abdominal imaging performed. Where performed, CT chest revealed suspicious findings in a significant number of patients, the vast majority of whom had a normal or near normal CEA. Future studies are required to define optimal preoperative staging.

[The impact of intra operative ultrasound in metastases liver surgery]

BACKGROUND

Twenty-five to 50% of the patients with hepatic metastases are potential candidates for curative surgery. Intraoperative ultrasound has been employed to guide the surgery.

AIM

To evaluate this method in liver surgeries and compare it to other imaging methods.

PATIENTS AND METHODS

Thirty-five patients (20 females, with median age of 56 years) with hepatic metastases were prospectively studied between February 2001 and July 2003. Patients had as primary tumors: colorectal cancer (24), neuroendocrine tumors (3), renal cell carcinoma (2), melanoma (2), others (4). Each patient was submitted to at least: computed tomography (30), ultrasonography (14) and magnetic resonance imaging (8). Intraoperative ultrasound was performed in all patients in order to detect liver nodules. The number and location of liver lesions were compared to preoperative results.

RESULTS

Intraoperative ultrasound was useful in 23 (65.6%) of the 35 surgeries and changed the planned surgical strategy in 9 (25.7%). There was a statistical significant correlation between the mean number of nodules identified by ultrasonography, computed tomography, magnetic resonance imaging and intraoperative ultrasound. We found no statistical difference between magnetic resonance imaging and intraoperative ultrasound in identifying hepatic nodules. Fifty-five nodules were submitted to histological evaluation, the gold standard method and 52/55 (94.5%) were identified by intraoperative ultrasound. Intraoperative ultrasound identified 91.6% of the smaller than 1.5 cm lesions, ultrasonography identified 15.0% of them, computed tomography 33.3% and magnetic resonance imaging 66.6%.

CONCLUSIONS

Intraoperative ultrasound is crucial in the evaluation and decision making in hepatic surgery. Intraoperative ultrasound presents the highest sensibility in the detection of hepatic nodules compared to other imaging methods, especially for small lesions.

Intraoperative ultrasound

Intraoperative ultrasound (IOUS) can provide various diagnostic information that is otherwise not available, and can guide or assist various surgical procedures in real time. With refinement of equipment, IOUS is currently used in a wide variety of surgical operations,such as hepatobiliary, pancreatic, endocrine, cardiovascular,and neurologic surgery. Our overview of IOUS, including instrumentation,techniques, indications, advantages, disadvantages,and future perspective, is described in this article. Being safe, quick, accurate, and versatile intraoperatively, IOUS is a valuable technique that surgeons are recommended to master to improve intraoperative decision making and surgical procedures.

A critical review of the major indicators of prognosis after resection of hepatic metastases from colorectal carcinoma

Hepatic resections for metastatic colorectal cancer have dramatically increased, and there is clear evidence of the effectiveness of this type of surgery. Controversy, however, persists regarding appropriate patient selection, extent and timing of liver resection, and adjuvant or alternative therapeutic options. This article reviews the authors' experience with more than 600 hepatic resections and the relevant literature is discussed. The results underscore the importance of macroscopically and histologically complete tumor clearance, a so-called "R0 resection."

Preoperative evaluation of hepatic lesions for the staging of hepatocellular and metastatic liver carcinoma using endoscopic ultrasonography

BACKGROUND

Noninvasive imaging techniques, such as dynamic computed tomography (CT), magnetic resonance imaging and transabdominal ultrasonography are limited in their ability to detect hepatic lesions less than one cm. Intraoperative ultrasonography (IOUS) is currently the most sensitive modality for the detection of small hepatic lesions. However, IOUS is invasive requiring laparoscopy or formal laparotomy. We sought to evaluate the feasibility of using endoscopic ultrasonograhpy (EUS) for the detection and diagnosis of hepatic masses in patients with hepatocellular cancer (HCCA) and metastatic lesions (ML). We hypothesized that EUS could detect small (<1.0 cm) hepatic lesions undetectable by CT scan and could be used for biopsy of deep-seated hepatic lesions.

METHODS

Consecutive patients referred for EUS with suspected liver lesions were evaluated between July 2000 and October 2001. All patients underwent EUS using an Olympus (EM30) radial echoendoscope. If liver lesions were confirmed and fine needle aspiration (FNA) was deemed necessary, a linear array scope was used and an FNA performed with a 22-gauge needle. Two passes were made for each lesion.

RESULTS

14 patients underwent evaluation with dynamic CT scans and EUS. In all 14 patients, EUS successfully identified hepatic lesions ranging in size from 0.3 cm to 14 cm (right lobe: n = 3, left lobe: n = 1, bilobar: n = 8). Moreover, EUS identified new or additional lesions in 28% (4 of 14) of the patients, all less than 0.5 cm in size (HCCA: n = 2, ML: n = 2), influencing the clinical management. In 2 of 14 patients EUS identified liver lesions, previously described as suspicious by CT scan, to be hemangiomas. Nine patients underwent EUS-guided FNA of hepatic lesions (deep seated: n = 3, superficial: n = 6). All FNA passes yielded adequate specimens (malignant: n = 8, benign: n = 1).

CONCLUSIONS

Our preliminary experience suggests that EUS is a feasible preoperative staging tool for liver masses suspected to be HCCA or metastatic lesions. EUS can detect small hepatic lesions previously undetected by dynamic CT scans. Furthermore, EUS-guided FNA can confirm additional HCCA liver lesions or liver metastases, in deep-seated locations, upstaging patients and changing clinical management.

Multi-detector row helical CT in preoperative assessment of small (< or = 1.5 cm) liver metastases: is thinner collimation better?

PURPOSE

To determine the value of collimations less than 5 mm in detecting hepatic metastases 1.5 cm or smaller by using multi-detector row helical computed tomography (CT).

MATERIALS AND METHODS

Thirty-one patients underwent contrast material-enhanced multi-detector row helical CT before hepatic resection in this prospective study. Images were reconstructed at collimations of 5.00, 3.75, and 2.50 mm with 50% overlap and reviewed independently by three radiologists. Each lesion was characterized as metastatic, benign, or equivocal and graded for conspicuity. Criterion standards were pathologic assessment of the resected liver and follow-up of the nonresected liver. Only lesions 1.5 cm or smaller were analyzed.

RESULTS

There were a total of 88 liver lesions 1.5 cm or smaller, and 25 of these were metastases. Pooled sensitivity for all lesions improved with thinner collimation (66% [58 of 88 lesions], 69% [61 of 88], and 82% [72 of 88] at collimations of 5.00, 3.75, and 2.50 mm, respectively), and this was statistically significant (P =.01). However, no significant difference was noted between collimations in the pooled sensitivity for metastatic lesions (80% [20 of 25 lesions] at all collimations) (P >.99). No statistical difference was noted in the conspicuity of lesions at different collimations (P =.18).

CONCLUSION

Image reconstruction with multi-detector row helical CT at collimations less than 5 mm may not improve sensitivity in the detection of hepatic metastases 1.5 cm or smaller.

Follow-up of patients with colorectal cancer: numbers needed to test and treat

Follow-up after curative treatment of patients with colorectal cancer has as its main aims the quality assessment of the treatment given, patient support, and improved outcome by the early detection and treatment of cancer recurrence. How often, and to what extent, the final aim, improved survival, is indeed realised is so far unclear. A literature search was performed to provide quantitative estimates for the main determinants of the effectiveness of the follow-up. Data were extracted from a total of 267 articles and databases, and were aggregated using modern meta-analytic methods. In order to provide one more colorectal cancer patient with long-term survival through follow-up, 360 positive follow-up tests and 11 operations for colorectal cancer recurrence are needed. In the remaining 359 tests and 10 operations, either no gains are achieved or harm is done. As the third aim of colorectal cancer follow-up, improved survival, is realised in only few patients, follow-up should focus less on diagnosis and treatment of recurrences. It should be of limited intensity and duration (3 years), and the search for preclinical cancer recurrence should primarily be performed by carcino-embryonic antigen (CEA) testing and ultrasound (US). The focus of colorectal cancer follow-up should shift from the early detection of recurrence towards quality assessment and patient support. As support that is as good or even better can be provided by a patient's general practitioner (GP) or by specialised nursing personnel, there is no need for routine follow-up to be performed by the surgeon.

Combined colon and hepatic resection for synchronous colorectal liver metastases

BACKGROUND AND OBJECTIVES

The surgical strategy for the treatment of resectable synchronous hepatic metastases of colorectal cancer remains controversial. This study was performed to assess the outcome of combined resection of colorectal cancer and liver metastases.

METHODS

The perioperative data, morbidity, and survival of the patients who underwent combined colon and liver resections for synchronous colorectal liver metastases from 1988 to 1999 were compared to the parameters of the patients who underwent colon resection followed by resection of liver metastases in a staged setting.

RESULTS

198 hepatic resections were performed, of which 112 procedures in 103 patients were done for metastatic colorectal carcinoma. Twenty six patients (25%) had combined hepatic and colon resection and were compared to 86 patients with metachronous metastases who underwent colon and hepatic resection in the staging setting. Postoperative morbidity was 27 and 35%, respectively. There was no hospital mortality in the combined group vs. 2.3% in the staged group. Blood loss, intensive care unit (ICU) stay and length of postoperative stay (LOS) were similar in both groups. The 5 years cumulative survival of the group after combined surgery was 28% vs. 27% of the group after isolated hepatic resections (P = 0.21).

CONCLUSION

Combined colon and hepatic resection is a safe and efficient procedure for the treatment of synchronous colorectal liver metastases. It can be performed with acceptable morbidity and no perioperative mortality. The survival after combined procedure is comparable to the one achieved after staged procedure of colon resection followed by liver resection.

Surgical management of hepatic metastases from colorectal malignancies

Liver metastasis represents the major cause of death of patients who have been treated for colorectal adenocarcinoma. Spontaneous survival rarely exceeds two years. Surgery can offer long-term survival and resection should be considered when liver metastases can be totally resected with clear margins and when there is no non-resectable extra-hepatic disease. The choice between anatomical or wedge resection depends on the number and the location of the metastases but does not influence survival. Clamping methods limit blood loss. Operative mortality is generally less than 5%. The five-year survival rate after surgical resection varies from 20% to 45% according to several prognostic factors. The longer survival is observed in patients with fewer than four lesions, with lesions smaller than 4 cm, without extra-hepatic disease, with lesions that appeared more than two years after the resection of a stage I or II colorectal cancer and whose CEA level is normal. After resection, follow-up can detect hepatic recurrence that can be treated with repeat hepatectomy. The efficacy of systemic chemotherapy using new agents can increase the number of patients amenable to surgery. Regional therapies with cryotherapy or radiofrequency ablation can help to treat unresectable or non-totally resectable lesions and may improve survival. The effects on survival of adjuvant treatments, including pre- or postoperative systemic or postoperative intra-arterial chemotherapy, are currently under evaluation.

Hepatic metastases from colorectal cancer: preoperative detection and assessment of resectability with helical CT

PURPOSE

To prospectively evaluate helical computed tomography (CT) in the preoperative detection of hepatic metastases and assessment of resectability with surgical, intraoperative ultrasonographic (US), and histopathologic correlation.

MATERIALS AND METHODS

Between October 1995 and December 1998, preoperative staging with helical CT (5-mm collimation; reconstruction interval, 5 mm) was performed in 157 patients with hepatic metastases. Iodinated contrast material was injected intravenously (160-170 mL; rate, 2.5-3.0 mL/sec); acquisition began at 60-70 seconds. Four radiologists prospectively assessed the metastatic involvement of the liver by indicating the number and location of the lesions; resection was indicated in 113 patients (119 instances). Helical CT findings were correlated with pathologic and surgical findings on a lesion-by-lesion basis.

RESULTS

Intraoperative US, palpation, and histopathologic examination revealed 290 liver metastases; helical CT correctly depicted 247. Helical CT results were the following: overall detection rate, 85.1% (95% CI: 80.8%, 89.3%); positive predictive value, 96.1% (95% CI: 92.9%, 98.1%); and false-positive rate, 3.9% (10 of 257 findings; 95% CI: 1.9%, 7.1%). False-positive findings were related to hemangioendothelioma, hemangioma, hepatic peliosis, biliary adenoma, centrilobar hemorrhage, biliary hamartoma, periportal fibrosis, and normal liver parenchyma. Curative resection was performed in 112 instances with a resectability rate of 94.1%. Four-year patient survival rate was 58.6%.

CONCLUSION

Helical CT is a noninvasive, reliable, and accurate technique for imaging the liver and should be considered as the standard preoperative work-up of hepatic metastases from colorectal cancer.

Role of laparoscopy in the staging of malignant disease

Although diagnostic laparoscopy has been used by surgeons and gastroenterologists since the early 1900s, today's surgical oncologists have been relatively slow to embrace this technology. Together with the fervor and benefits afforded by laparoscopic therapeutic interventions in the management of patients with benign disease and the diagnostic usefulness in blunt trauma and abdominal pain, awareness has been rekindled regarding the advantages of laparoscopy for the staging of abdominal malignancy. As surgeons begin to realize that extirpative procedures are doomed to failure in curing patients with diffuse abdominal metastases disclosed on laparoscopic assessment, palliative measures, such as stent placement, ablative procedures, balloon dilatation, intraluminal high-dose radiation, and laser techniques will be used commonly by surgical endoscopists and gastroenterologists. Similarly, it is hoped that the use of systemic chemotherapy will achieve better specificity in cell destruction in patients identified laparoscopically to have uncontained disease in the abdominal cavity. The sensitivity of sonography combined with laparoscopy has been shown to approach that of celiotomy in the evaluation of solid organs, thereby avoiding unnecessary laparotomy and its associated morbidities. Using sonography as a complement to laparoscopy will extend the usefulness of both techniques. The application of laparoscopy and the advent of miniaturized laparoscopic instrumentation (Fig. 7), both diagnostic and therapeutic, in the management of patients with abdominal malignancy will be limited only by the creativity and expertise of physicians and instrument makers.

Surface registration for use in interactive, image-guided liver surgery

OBJECTIVE

Liver surgery is difficult because of limited external landmarks, significant vascularity, and inexact definition of intra-hepatic anatomy. Intra-operative ultrasound (IOUS) has been widely used in an attempt to overcome these difficulties, but is limited by its two-dimensional nature, inter-user variability, and image obliteration with ablative or resectional techniques. Because the anatomy of the liver and intra-operative removal of hepatic ligaments make intrinsic or extrinsic point-based registration impractical, we have implemented a surface registration technique to map physical space into CT image space, and have tested the accuracy of this method on an anatomical liver phantom with embedded tumor targets.

MATERIALS AND METHODS

Liver phantoms were created from anatomically correct molds with "tumors" embedded within the substance of the liver. Helical CT scans were performed with 3-mm slices. Using an optically active position sensor, the surface of the liver was digitized according to anatomical segments. A surface registration was performed and RMS errors of the locations of internal tumors are presented as verification. An initial point-based marker registration was performed and considered the "gold standard" for error measurement.

RESULTS

Errors for surface registration were 2.9 mm for the entire surface and 2.8 mm for embedded targets.

CONCLUSION

This is an initial study considering the use of surface registration for the purpose of physical-to-image registration in the area of liver surgery.

Prospective, blinded comparison of laparoscopic ultrasonography vs. contrast-enhanced computerized tomography for liver assessment in patients undergoing colorectal carcinoma surgery

PURPOSE

To prospectively and blindly compare intraoperative laparoscopic ultrasonography to preoperative contrast-enhanced computerized tomography in detecting liver lesions in colorectal cancer patients. Additionally, we compared conventional (open) intraoperative ultrasonography with bimanual liver palpation to contrast-enhanced computerized tomography in a subset of patients.

METHODS

From December 1995 to March 1998, 77 consecutive patients underwent curative (n = 63) or palliative (n = 14) resections for colorectal cancer. All patients undergoing curative resections were randomized to either laparoscopic (n = 34) or conventional (n = 29) surgery after informed consent. All patients underwent contrast-enhanced computerized tomography, diagnostic laparoscopy, and laparoscopic ultrasonography before resection. In those patients who had conventional procedures, intraoperative ultrasonography with bimanual liver palpation was also done. All laparoscopic ultrasonography and intraoperative ultrasonography evaluations were performed by one of two radiologists who were blinded to the CT results. All hepatic segments were scanned using a standardized method. The yield of each modality was calculated using the number of lesions identified by each imaging modality divided by the total number of lesions identified.

RESULTS

In 43 of the 77 patients, both the laparoscopic ultrasonography and CT scan were negative for any liver lesions. In 34 patients, a total of 130 lesions were detected by laparoscopic ultrasonography, CT, or both. When compared with laparoscopic ultrasonography, intraoperative ultrasonography with bimanual liver palpation identified one additional metastatic lesion and no additional benign lesions. laparoscopic ultrasonography identified two patients with mets who had negative preoperative contrast-enhanced computerized tomography.

CONCLUSIONS

Laparoscopic ultrasonography of the liver at the time of primary resection of colorectal cancer yields more lesions than preoperative contrast-enhanced computerized tomography and should be considered for routine use during laparoscopic oncologic colorectal surgery.

Selection of patients for resection of colorectal metastases to the liver using diagnostic laparoscopy and laparoscopic ultrasonography

OBJECTIVE

To assess the value of diagnostic laparoscopy (DL) and laparoscopic ultrasonography (LUS) in the staging and selection of patients with colorectal liver metastasis.

SUMMARY BACKGROUND DATA

Preoperative imaging modalities such as ultrasound, computed tomography, and magnetic resonance imaging are limited in the assessment of the number and exact location of hepatic metastases and in the detection of extrahepatic metastatic disease. Consequently, the surgeon is often faced with a discrepancy between preoperative imaging results and perioperative findings, resulting in either a different resection than planned or no resection at all.

METHODS

Fifty consecutive patients were planned for DL and LUS in a separate surgical sitting to assess the resectability of their liver metastases. All patients were considered to be candidates for resection on the basis of preoperative imaging studies.

RESULTS

Laparoscopy could not be performed in 3 of the 50 patients because of dense adhesions. The remaining 47 patients underwent DL. On the basis of DL and LUS, 18 (38%) patients were ruled out as candidates for resection. Of the 29 patients who subsequently underwent open exploration and intraoperative ultrasonography, another 6 (13%) were deemed to have unresectable disease.

CONCLUSIONS

The combination of DL and LUS significantly improves the selection of candidates for resection of colorectal liver metastases and effectively reduces the number of unnecessary laparotomies.

Câncer do reto médio: avaliação do procedimento cirúrgico

A conduta no tratamento cirúrgico do câncer do reto médio é ainda controversa. Vários procedimentos cirúrgicos foram avaliados, retrospectivamente, em noventa doentes operados durante o período de fevereiro de 1990 a junho de 1997. Deste total, 43 (47,7%) doentes eram do sexo feminino e 47 (52,3%) do masculino. A idade variou entre 20 e 90 anos, com média de 60,2 anos. Os principais sintomas e sinais foram puxo e tenesmo, hematoquesia e emagrecimento. O tempo decorrido desde o início dos sintomas até o diagnóstico variou de dois a 24 meses, com média de 7,5 meses. A amputação abdômino-perineal do reto foi realizada em 17 doentes (18,8%) e a complicação mais freqüente foi a deiscência da ferida perineal, em 47% dos casos. Um doente (1,1 %) foi submetido a proctocolectomia total, evoluindo sem intercorrências. A operação de Hartmann foi feita em 26 doentes (28,8%), ocorrendo 7,6% de morbidade e 7,6% de mortalidade, em virtude de complicações clínicas. Em 26 doentes (28,8%), foi realizada ressecção anterior seguida de anastomose. Em dez (11,1%), foi realizada anastomose manual e não houve complicações. Nos outros 16 (17,7%) foi feita anastomose mecânica, havendo três deiscências e um óbito, relacionado a complicações clínicas. Em oito doentes (8,8%), foi realizada ressecção com abaixamento coloanal, ocorrendo 50% de complicações, devido à necrose e à retração do cólon abaixado. Houve apenas um óbito relacionado à complicação cirúrgica. Em 12 doentes (13,3%) não foi efetuada a ressecção do tumor, em decorrência de precárias condições clínicas dos mesmos e falta de critérios de ressecabilidade da lesão. Concluímos que o procedimento cirúrgico adequado no tratamento do câncer do reto médio depende de estadiamento criterioso, considerando o grau de diferenciação celular, a presença de metástase, a condição local do tumor, a situação clínica do doente e a experiência da equipe cirúrgica.

The accuracy of laparoscopic ultrasound in the detection of colorectal cancer liver metastases

BACKGROUND

The most sensitive and specific method of detecting colorectal cancer hepatic metastases has been shown to be a combination of careful intraoperative palpation and intraoperative ultrasound. Although there has been growing interest in laparoscopic surgical therapy for colorectal cancer, the ability of this technique to adequately evaluate the liver for small metastases has been unknown. This study was undertaken to compare laparoscopic liver ultrasound to the gold standard of open palpation and intraoperative ultrasound in detecting hepatic metastases from colorectal cancer.

METHODS

A preliminary animal model was first performed in adult pigs. Eighteen liver "lesions" were created with chlorhexidine gluconate under laparoscopic guidance. A blinded surgeon then performed laparoscopic liver ultrasound followed by open ultrasound and palpation, comparing the accuracy of these techniques in detecting the lesions. In a second study, 15 patients undergoing laparotomy for colorectal cancer underwent preliminary laparoscopic liver ultrasound followed by open palpation and intraoperative ultrasound to compare these methods of liver evaluation.

RESULTS

Laparoscopic liver ultrasound detected 17 of 18 lesions created in the pig livers, for a sensitivity of 94.4%. There were two false negatives, for a specificity of 77.7%. Laparoscopic liver ultrasound detected 4 of the 5 liver metastases in the human study, for a sensitivity of 80%. There was a single false negative, for a specificity of 90.9%. Several technical difficulties and their solutions are discussed.

CONCLUSIONS

With several technical modifications guided by our initial experience, we believe laparoscopic liver ultrasound can be an effective way of evaluating the liver for metastases during laparoscopic colorectal resection for cancer.

Surgeon-performed ultrasound: its use in clinical practice

OBJECTIVE

To highlight areas where surgeon-performed ultrasound (US) is an effective diagnostic and therapeutic tool.

SUMMARY BACKGROUND DATA

The success of US in trauma and technologic advances have enhanced the interest and ability of surgeons to perform their own US examinations.

METHODS

General surgeons perform US examinations of the thyroid gland, breast, gastrointestinal tract, peritoneal cavity (laparoscopy), and vascular system. Essentials of these examinations are discussed and a plan for educating surgical residents in US is outlined.

RESULTS

Focused assessment for the sonographic examination of the trauma patient, or FAST, is replacing central venous pressure measurements to detect hemopericardium and diagnostic peritoneal lavage to detect hemoperitoneum. Bedside US can be used to detect a pleural effusion so well in critically ill patients that lateral decubitus x-rays are rarely needed. US-directed biopsy of breast lesions is a common office procedure. Laparoscopic US allows tumor staging without formal celiotomy, and many hepatic and pancreatic surgical procedures include US as an adjunct. Endoscopic and endorectal US have added a new dimension to the assessment of many gastrointestinal lesions. Color flow duplex imaging and endoluminal US have significantly expanded the diagnostic and therapeutic aspects of vascular imaging. The training program developed at Emory University and Grady Memorial Hospital is offered as a model for educating surgical residents in US techniques.

CONCLUSIONS

US is a valuable addition to the general surgeon's diagnostic armamentarium and is rapidly becoming an integral part of the surgeon's clinical practice.

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.

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.

Prognostic value of negative intraoperative ultrasonography in primary colorectal cancer

The risk of developing recurrent tumour was assessed in a group of 85 patients with primary colorectal cancer who had a negative intraoperative ultrasonographic examination at the time of primary tumour resection. At a median follow-up of 40 months liver metastases had developed in 14 patients (16 per cent). Dukes classification of the primary tumours was stage A, B and C in one, three and ten patients respectively. The interval between primary tumour resection and detection of metastases varied from 6 to 24 months but all became evident within 2 years. Sixteen patients (19 per cent) presented with extrahepatic recurrence, one of whom also developed liver metastases. A negative intraoperative ultrasonographic examination did not prove to be a favourable prognostic factor which allowed exclusion from follow-up or adjuvant chemotherapy.

Intraoperative laparoscopic liver ultrasonography for staging of colorectal cancer. Initial experience

PURPOSE

This study was undertaken to evaluate the feasibility of intraoperative laparoscopic ultrasonography (ILUS) to completely scan all anatomic segments of the liver through a single port site during laparoscopic resection for colorectal cancer.

METHODS

ILUS was performed in patients who were undergoing laparoscopic colorectal cancer surgery using the following approach: 1) presence of a radiologist in the operating room; 2) introduction of the probe through a single cannula site; 3) standardized sequence of four probe positions on liver surface; 4) identification of all major vascular/biliary hepatic structures as a guideline to scan all parenchymal segments of the liver.

RESULTS

Twenty-two patients who were undergoing laparoscopic colorectal cancer surgery were prospectively enrolled. Computed tomography (CT) scan films were available for an immediate comparative analysis in the first 12 cases. Mean duration of the procedure was 10 (range, 5-15) minutes. All major vascular and biliary structures were identified in all patients. Sixteen focal abnormalities were identified by ILUS, and ten focal abnormalities were identified by CT scan in the same seven patients. In one patient, detection of a suspected metastasis not seen by preoperative CT scan led to conversion of the surgical procedure to a laparotomy.

CONCLUSIONS

ILUS is a safe and expeditious technique that permits scanning of all anatomic liver parenchyma segments through a single cannula site. Because intraoperative palpation of the liver is not possible during laparoscopic colorectal cancer surgery, ILUS should probably be a standard component of the curative laparoscopic colorectal cancer operation.

Intraoperative ultrasonography in the diagnosis of hepatic metastases during surgery for colorectal cancer

Approximately 20-25% of colorectal cancers have hepatic metastases at the time of operation and occult liver secondaries appear in 10-30% of curatively operated cases. Intraoperative liver ultrasonography has been reported to be the most accurate method for detecting colorectal metastases. A consecutive series of 119 colorectal cancer patients was studied by routine extracorporeal preoperative ultrasound (EUS), inspection and palpation of the liver at laparotomy and intraoperative liver ultrasound (IUS). 19 patients had liver metastases at the time of surgery. In eight, diagnosis was by EUS. Inspection and palpation yielded a further seven, and IUS alone a further four. Additional lesions were detected in 3 patients after preoperative ultrasound and in 6 patients following intraoperative palpation of the liver. In a further 4 cases IUS demonstrated additional metastases. Follow up for a median 38 months (12-59) was by clinical examination and six monthly liver ultrasound. During this time 8 patients, who were thought to have a clear liver, developed hepatic metastases. The mean time from surgery to the detection of occult hepatic metastases was 14.7 (8-26) months and 4 of these appeared in the second year. Intraoperative ultrasonography is a sensitive and useful method in detecting liver metastases, and may improve clinical staging and the selection of patients for further therapy. However some occult hepatic metastases will remain undetected.