Charles M. O'Malley

Colonic Abnormalities on CT in Adult Hospitalized Patients with Clostridium difficile Colitis: Prevalence and Significance of Findings

OBJECTIVE The purpose of this study was to determine the prevalence of an abnormal colon on CT in adult inpatients with Clostridium difficile colitis, compare the clinical presentation of these patients, and determine whether CT findings predicted the need for surgical treatment. MATERIALS AND METHODS Over a 21-month period, 152 of 572 inpatients with C. difficile colitis were identified and had CT scans performed within 2 weeks of the diagnosis. These were independently and retrospectively reviewed by two reviewers. Those with colonic wall thickness greater than 4 mm were considered positive (CT-positive patients) and were further reviewed for specific findings in the colon. All 152 patients with CT scans were also retrospectively reviewed using the hospital information system for certain clinical parameters, admitting diagnoses, and reasons for scanning. The following were compared using several statistical tests: clinical parameters in CT-positive and CT-negative patients and surgical and nonsurgical groups to determine if positive scans or surgical treatment could be clinically predicted; specific CT findings in CT-positive patients to see if an association was found with clinical parameters or surgical treatment; and admitting diagnoses and reasons for scanning in scanned and unscanned populations to see which patients were more likely to undergo CT. RESULTS Seventy-six (50%) of 152 scanned hospitalized patients with C. difficile colitis were CT-positive. These patients most often had segmental involvement (50 [66%] of 76 patients), with the rectum (60 [82%] of 73 patients) and sigmoid colon (61 [82%] of 74 patients) most often affected. Positive scans were associated with increased WBC, abdominal pain, and diarrhea. Patients with signs and symptoms of infection or abdominal complaints were more likely to be scanned. No statistical correlation was found between specific CT findings and clinical parameters or clinical parameters and patients requiring surgery. There was no predictive value of specific CT findings for surgical treatment. CONCLUSION Half of the patients scanned had an abnormal CT, with segmental colonic disease more common than diffuse. Positive scans were more likely in patients with leukocytosis, abdominal pain, and fever. Specific CT findings did not correlate with clinical parameters and could not predict surgical treatment.

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.

Image Guided Percutaneous Probe Ablation for Renal Tumors in 65 Solitary Kidneys: Functional and Oncological Outcomes

PURPOSE We evaluated the oncological and functional outcomes of computerized tomography guided percutaneous cryotherapy or radio frequency ablation of kidney tumors in patients with a solitary kidney. MATERIALS AND METHODS We reviewed the medical charts of patients with a solitary kidney who underwent percutaneous probe ablation for renal masses at our institution from April 2002 through March 2010. Followup consisted of computerized tomography or magnetic resonance imaging 1 day postoperatively, at 3, 6 and 12 months, and annually thereafter. Serum creatinine and estimated glomerular filtration rate were used to measure renal function. The cryotherapy and radio frequency ablation groups were compared for demographics, the 2-year actuarial survival rate and renal function. RESULTS Overall 65 patients were included in this retrospective analysis, of whom 29 (44.6%) underwent cryotherapy and 36 (55.4%) underwent radio frequency ablation. Median followup was 15.1 (IQR 4.4 to 32.9) and 38.8 months (13.8 to 50.7), respectively. The 2 groups were comparable in median age, body mass index, American Society of Anesthesiologists score, tumor size and preoperative estimated glomerular filtration rate. The 3 primary treatment failures, including 1 after cryotherapy and 2 after radio frequency ablation, were successfully re-treated with thermal ablation. There were 14 recurrences after radio frequency ablation and 3 after cryotherapy. Two-year actuarial overall, cancer specific, recurrence-free and metastasis-free survival rates for cryotherapy vs radio frequency ablation were 89% vs 93%, 100% vs 96%, 69% vs 58% and 86% vs 91%, respectively. For each group no significant decrease in renal functional parameters was found at the latest followup visit. CONCLUSIONS Computerized tomography guided percutaneous probe ablation represents a safe treatment option in surgical patients at high risk with a solitary kidney. It provides low morbidity, acceptable short-term cancer control and minimal clinical impact on postoperative renal function.

Probe ablation as salvage therapy for renal tumors in von Hippel-Lindau patients: The Cleveland Clinic experience with 3 years follow-up

BACKGROUND To evaluate the efficacy and safety of probe ablative therapy as salvage treatment for renal tumor in von Hippel-Lindau (VHL) patients after previous partial nephrectomy (PN). METHODS Medical records of VHL patients undergoing probe ablative treatment for renal tumors from March 2003 to January 2010 at our institution were retrospectively analyzed. RESULTS Fourteen VHL patients who were submitted to salvage probe ablative therapy were included in the analysis. Twelve patients (85%) had a solitary kidney. Overall, 33 tumors were ablated by either percutaneous cryoablation (P-Cryo) (n of procedures = 13), radiofrequency ablation (RFA) (n = 14), and laparoscopic cryoablation (L-Cryo) (n = 3). Average maximal renal tumor diameter was 2.6 ± 1 cm. Average ablation time was 18.3 ± 2.1 minutes for P-Cryo, 36.7 ± 17 minutes for RFA, and 17.3 ± 4 minutes for L-Cryo. All procedures were successfully completed without transfusions and intraoperative complications. No early postoperative complications were recorded. Postoperative decline in renal function was minimal and not clinically significant. With a mean follow-up of 37.6 months (range 12-82), 4 patients had a suspicious recurrence on computed tomography/magnetic resonance imaging (CT/MRI) scan and in 3 of them a re-ablation was performed. Actuarial overall and cancer-specific survivals were 92% and 100%, respectively. CONCLUSIONS Probe ablative therapy seems to represent a suitable treatment option for VHL patients with a previous history of PN as it offers a repeatable operation, with a high technical success rate and causing minor changes in renal function.

Intraoperative laparoscopic liver ultrasonography for staging of colorectal cancer

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.

Third Prize: Synchronized Real-Time Ultrasonography and Three-Dimensional Computed Tomography Scan Navigation During Percutaneous Renal Cryoablation in a Porcine Model

AIM To investigate the accuracy of percutaneous cryoablation for kidney tumors performed under combined real-time ultrasonography (US) and three-dimensional (3D) CT scan navigation in a porcine model. MATERIALS AND METHODS After percutaneously injecting 2 to 6 tumor mimic lesions in 11 pigs, a CT scan was performed and digital data were saved into a navigation system (Real-Time Virtual Sonography [RVS]) that allows 3D reconstruction and synchronization with real-time US images. The cryoprobe was guided percutaneously into the kidney tumor mimic, and ice ball formation was monitored continuously during cryoablation using the RVS system. Kidneys were harvested and sent for gross pathologic and histopathologic analysis at days 0, 15, and 30 postoperatively. RESULTS Thirty-five renal tumor mimics were created and treated by percutaneous cryotherapy; tumor mimic locations were as follows: 16 tumors (46%) in the lower pole, 14 (40%) in the central region, and 5 (14%) in the upper pole. Eleven tumor mimics (31%) were intraparenchymal, and 24 (69%) subcapsular. The synchronization between the CT scan 3D reconstructed images and real-time US was successful in all cases. The mean tumor size was 2 cm (range, 1.2-4 cm). Mean cryonecrosis size was 3.3, 3.7, and 2.8 cm at days 0, 15, and 30, respectively. Three (8.5%) positive margins were found on the macroscopic and microscopic analysis. CONCLUSIONS RVS imaging system synchronizing real-time US with preoperative CT scan is a feasible and safe technique for percutaneous probe ablation of kidney tumors.

Stereotactic percutaneous cryoablation for renal tumors: initial clinical experience.

PURPOSE Percutaneous imaging guided tumor ablation has an increasingly prominent role as minimally invasive treatment for renal tumors. Precise cryoprobe placement is essential for successful ablation. CT-Nav is a novel stereotactic surgical navigation system with the potential to achieve precise percutaneous cryoprobe placement while decreasing radiation exposure compared to conventional computerized tomography guided procedures. MATERIALS AND METHODS We performed a prospective pilot study to evaluate the technical feasibility, safety and accuracy of the system during renal cryoablation. Patients with enhancing renal masses amenable to renal cryoablation underwent preoperative computerized tomography with a preplaced tracking sensor taped to the body. Using a stereroscopic infrared camera the tracking sensor was located 3-dimensionally and a tracking handle was used to guide the cryoprobe percutaneously based on preoperative preloaded computerized tomography. Demographic and perioperative data were added prospectively to an institutional review board approved database. Immediately after cryoprobe placement computerized tomography was repeated to confirm placement accuracy. RESULTS A total of 13 tumors in 10 patients were successfully cryoablated with the novel navigational system. Mean tumor size was 2.2 cm. Preoperative biopsy revealed renal cell carcinoma in 9 cases. Mean operative time was 155 minutes. No intraoperative or postoperative complications were noted. Mean length of stay was 9.5 hours. Mean targeting registration error was 4.2 mm. CONCLUSIONS Stereotactic percutaneous cryoablation for renal tumors offers the potential for safe, precise needle placement.