Minimally Invasive Management of Hepatic Metastases

Abstract

The introduction of laparoscopy for diagnosis of abdominal tumors has also allowed for the destruction of hepatic metastases by cryotherapy and radiofrequency ablation. The advantage of laparoscopically based therapy over the percutaneous treatment is the benefit of finding additional lesions that preoperative studies may not have detected. The results from available data in patients with metastatic colorectal carcinoma suggest an improvement in survival. Tumor ablation in patients offers an 18-to 36-month median survival and the possibility of 50% and 24% survival rates at 2 and 5 years, respectively. Patients with metastases from melanoma, breast, esophagus, lung, stomach, pancreas, and gynecologic malignancies have historically not demonstrated improved survival after hepatic resection. The value of hepatic tumor ablation for metastases from these lesions remains undetermined. he liver is a common site of metastatic disease for many malignancies. Surgical resection has traditionally been the mainstay of treatment; however, the majority of patients are not candidates for hepatic resection. Therefore, ablative methods provide an alternative treatment option. Destruction of hepatic metastases by cryotherapy or radiofrequency ablation is becoming commonplace, particularly with the development of minimally invasive techniques. Each method involves insertion of a probe through liver parenchyma into a hepatic neoplasm. Destruction of the lesion occurs as it is frozen to -180°C and subsequently thawed, or by heating it to greater than 50°C. Open cryosurgical hepatic procedures have been well described in the North American, Australian, and Asian literature; its role is established in selected patients with unresectable disease. Development radiofrequency needle probes and improvement in laparoscopic ultrasonography has allowed these procedures to be performed percutaneously as well as laparoscopically. Early results of laparoscopic cryoablation and percutaneous radiofrequency ablation reveal that they are safe and equally efficacious as open ablative procedures with less procedure-related morbidity and improved survival. Liver Metastases From Colorectal CancerThe liver is a common site for metastatic cancer in patients with colorectal carcinoma, second only to regional lymph nodes. The United States reports approximately 150,000 new cases of colorectal cancer per year. Up to 25% of the cases have liver metastases at the time of presentation, and 50% develop liver metastases within 5 years. Therefore, 75,000 patients per year are at risk of developing liver metastases from colorectal cancer. Twenty percent of patients with liver metastases (15,000 cases/yr) have disease limited to this organ. This is the group of patients that ablative therapies may potentially be curative or provide improved survival. 1,2The natural history of colorectal metastases to the liver has been well described.3 If untreated, patient survival averages 6 to 21 months. The extent of metastatic disease is the single most important factor for surv...

Laparoscopic-Assisted Ablation of Liver Tumors

“…The radiofrequency generator provides an alternating current causing the oscillation of ions, resulting in a tissue temperature of up to 100° C. This energy is conducted into the surrounding tissue in a predictable manner resulting in coagulative necrosis. The increase in local temperature results in protein denaturation, ultimately leading to cellular destruction and tissue necrosis [12]. Unfortunately the presence of a heat sink can occur near medium to larger vessels along with an increase in the patient's core temperature.…”

Liver tumor ablation: Percutaneous and open approaches

“…Further clinical studies are warranted to clarify the ultimate role of ablation therapies in the management of patients with liver cancer. [192,205,206] 1998 CS 9 patients Lap CSA is safe and feasible CRLM, colorectal liver metastasis; CSA, cryosurgical ablation; CS, case series; nRCT, non-randomized controlled trial. [214] 234 CS L 18.4% actual 5-year survival Sorensen et al [215] 102 CS P 44% OS at 5-year Aloia et al [190] 30 CS P, O 27% 5-year OS Jakobs et al [216] 68 CS P 68% OS at 3-year Pereira et al [195] 177 CS P 55% 5-year OS Berber et al [217] 135 CS L Median OS 28.9 months; CEA level, size and number of lesions are predictors of OS Abdalla et al [178] 57 CS O 37% 3-year OS Lencioni et al [193,194] 423 CS P 24% 5-year cumulative OS; 56% 5-year OS in patients with single lesion 2.5 cm size Gillams et al [196] 167 CS P 30% 5-year OS in patients with 5 metastases, 5 cm max size and no extra-hepatic disease Solbiati et al [218] 117 CS P 67/117 AWD after 28 months; 46% 3-year OS Gillams et al [219] 69 CS P 34% OS at 3-year Lencioni et al [207] 29 CS P 93% OS at 1-year Solbiati et al [208,220] …”

“…Minimally invasive [192] surgical approaches have been well documented. However, only 10-25% of patients with metastases isolated to the liver are eligible for resection [193], because of anatomic constraints of tumor, extrahepatic disease, inadequate hepatic functional reserve or concurrent medical comorbidities.…”

“…Table VI documents the outcomes of studies [184,192,[203][204][205][206] metastatic disease in patients not suitable for hepatic resection, and reported successful local tumor control [207][208][209][210]. Recently, data on long-term survival of nonsurgical patients with hepatic colorectal metastases treated with RFA have become available.…”