Kambiz Kosari

Local, intrahepatic, and systemic recurrence patterns after radiofrequency ablation of hepatic malignancies

The objective of this study was to describe the recurrence patterns in patients with unresectable hepatic malignancies treated with radiofrequency ablation (RFA). As RFA is applied more widely to patients with hepatic tumors, a better understanding of the biologic behavior of these tumors and the risk of recurrence, both in the liver and systemically, is needed. A multidisciplinary team evaluated patients referredh for RFA and followed them prospectively to assess local, intrahepatic, and extrahepatic disease recurrence and complication rates. Forty-five patients with 143 lesions and a minimum follow-up of 6 months (median 19.5 months) were treated. Overall, 7.7% of treated lesions had local recurrence. New intrahepatic disease was seen in 49% of patients, and 24% had evidence of new systemic tumor progression. Patients with colorectal metastatic lesions > 4 cm at the time of the first RFA were more likely to present with local recurrence (P = 0.048). Complications occurred in 27% of patients. Although RFA has a satisfactory local failure rate and safety profile, the patient population being treated is at high risk of developing new disease. Multimodality adjuvant therapy will be necessary to realize the full potential of hepatic malignancy control with RFA.

Liver regeneration after adult living donor and deceased donor split-liver transplants.

As the number of living donor (LD) and deceased donor (DD) split‐liver transplants (SLTs) have increased over the last 5 years, so too has the interest in liver regeneration after such partial‐liver transplants. We looked at liver regeneration, as measured by computed tomography (CT) volumetrics, to see if there were significant differences among LDs, right‐lobe LD recipients, and SLT recipients. We measured liver volume at 3 months postoperatively by using CT, and we compared the result to the patients ideal liver volume (ILV), which was calculated using a standard equation. The study group consisted of 70 adult patients who either had donated their right lobe for LD transplants (n = 24) or had undergone a partial‐liver transplant (right‐lobe LD transplants, n = 24; right‐lobe SLTs, n = 11; left‐lobe SLTs, n = 11). DD (vs. LDs) were younger (P < 0.01), were heavier (P = 0.06), and had longer ischemic times (P < 0.01). At 3 months postoperatively, LDs had attained 78.6% of their ILV, less than the percentage for right‐lobe LD recipients (103.9%; P = 0.0002), right‐lobe SLT recipients (113.6%; P = 0.01), and left‐lobe SLT recipients (119.7%; P = 0.0006). When liver size at the third postoperative month was compared with the liver size immediately postoperatively, LDs had a 1.85‐fold increase. This was smaller than the increase seen in right‐lobe LD recipients (2.08‐fold), right‐lobe SLT recipients (2.17‐fold), and left‐lobe SLT recipients (2.52‐fold). In conclusion, liver regeneration, as measured by CT volume, seems to be greatest in SLT recipients. LD recipients seem to have greater liver growth than their donors. The reason for this remains unclear. (Liver Transpl 2004;10:374–378.)

Radiofrequency ablation causes 'thermal fixation' of hepatocellular carcinoma: a post-liver transplant histopathologic study.

Abstract: Radiofrequency ablation (RFA) is increasingly used to treat hepatocellular carcinoma (HCC) in patients awaiting a liver transplant. Despite its increasing use, detailed histologic information is scarce regarding the nature of RFA‐treated lesions. We identified four chronic hepatitis C patients who had RFA of their HCC before their liver transplant. For these four patients, we conducted a detailed histopathologic analysis of the treated lesions in their explanted livers. The five lesions included immediate (4 d) and long‐term (14 months) post‐RFA specimens. Of the five lesions, four were completely ablated. The one incompletely ablated lesion was also treated with chemoembolization. In the acute post‐RFA period, a zone of interstitial hemorrhage occurred at the outer boundary of the lesion. Differing from classic tissue necrosis, the treated lesions all showed ‘thermal fixation’, with preserved tissue architecture and microscopic cellular detail. The cellular staining characteristics faded with time, but the treated tissue became brittle, resisted tissue breakdown, and generated a minimal wound healing response. At the periphery of the lesion, the fibrous septae of the cirrhotic liver and vascular structures appeared to demarcate or limit progression of the ablation front. A narrow hypocellular fibrous boundary with a focal ‘foreign body’ giant cell‐type reaction developed around the edge of the ablation zone. Thus, RFA can produce immediate and complete thermal fixation of select lesions with an appropriate liver margin and can provide a satisfactory treatment option for select HCC patients before a liver transplant.

Biliary cystadenomas: hormone receptor expression and clinical management.

Biliary cystadenomas with mesenchymal stroma are neoplasms whose growth may be hormone sensitive. This study profiled the immunohistochemistry of these lesions to clarify the pathophysiology and define clinical management. Twelve patients with biliary cystadenomas were identified. Tissue was tested with a panel of probes including estrogen and progesterone receptors and compared to pancreatic and ovarian cystadenomas. Epithelial ER, PR, CD117, or SMA expression was negative in all three tumors. Epithelial CD10 expression was seen in 60% biliary, 75% pancreatic, and 0% ovarian tumors. Biliary cystadenoma stromal expression was ER+ (70%), PR+ (60%), CD10+ (40%), and c-kit+ (0%). Symptoms were seen in 92% patients. Percutaneous sclerotherapy and incomplete resection were associated with recurrence. Enucleation was the least morbid surgical technique. A role for hormonally mediated growth of biliary cystadenomas occurring through the stroma, rather than the epithelium, is suggested. Management remains complete surgical resection.