Safety of percutaneous renal cryoablation: an international multicentre experience from the EuRECA retrospective percutaneous database.

OBJECTIVE: To investigate the safety profile of percutaneous cryoablation of renal tumours < 7 cm, utilising data extracted from an international multicentre registry. MATERIALS AND METHODS: A retrospective review of all immediate and delayed complications from a multicentre database was performed and was categorised according to the Clavien-Dindo classification. Statistical analysis was performed for both overall complications (all Clavien-Dindo) and major complications (Clavien-Dindo 3 to 5). The following criteria were identified as potential predictive factors for complications: centre number, modality of image guidance, tumour size (≤ 4 cm vs. > 4 cm), number of tumours treated in the same session (1 vs. > 1) and tumour histology. RESULTS: A total of 713 renal tumours underwent ablation in 647 individual sessions. In 596 of the cases, one tumour was treated; in the remaining 51 cases, several tumours were treated per session. Mean lesion size was 2.8 cm. Fifty-four complications (Clavien-Dindo 1 to 5) occurred as a result of the 647 procedures, corresponding to an overall complication rate of 8.3%. The most frequent complication was bleeding (3.2%), with 9 cases (1.4%) requiring subsequent treatment. The rate of major complication was 3.4%. The only statistically significant prognostic factor for a major complication was a tumour size > 4 cm. CONCLUSION: Percutaneous renal cryoablation is associated with a low rate of complications. Tumours measuring more than 4 cm are associated with a higher risk of major complications. KEY POINTS: • Percutaneous kidney cryoablation has a low rate of complications. • Bleeding is the most frequent complication. • A tumour size superior to 4 cm is a predictive factor of major complication.

Imaging appearances at follow-up after image-guided solid-organ abdominal tumour ablation.

The role of minimally invasive, locoregional therapies in cancer is increasingly driven by the detection of small asymptomatic disease either incidentally or under surveillance for a known primary malignancy. Percutaneous image-guided ablation has become established as a parenchyma-sparing tool in the management of small volume primary and metastatic disease in the liver as well as solitary renal masses. As ablation is non-extirpative, post-ablation imaging is critical for the assessment of treatment completion, recurrence, and complications. Within established regional cancer networks, understanding of normal post-ablation imaging appearances is essential for the early identification of primary treatment failure or local recurrence, which may be amenable to repeat treatment. We provide an imaging primer of two common ablation sites - kidney and liver - focusing on normal appearances and appreciation of local disease progression.

Guidelines for the management of gastroenteropancreatic neuroendocrine (including carcinoid) tumours (NETs).

These guidelines update previous guidance published in 2005. They have been revised by a group who are members of the UK and Ireland Neuroendocrine Tumour Society with endorsement from the clinical committees of the British Society of Gastroenterology, the Society for Endocrinology, the Association of Surgeons of Great Britain and Ireland (and its Surgical Specialty Associations), the British Society of Gastrointestinal and Abdominal Radiology and others. The authorship represents leaders of the various groups in the UK and Ireland Neuroendocrine Tumour Society, but a large amount of work has been carried out by other specialists, many of whom attended a guidelines conference in May 2009. We have attempted to represent this work in the acknowledgements section. Over the past few years, there have been advances in the management of neuroendocrine tumours, which have included clearer characterisation, more specific and therapeutically relevant diagnosis, and improved treatments. However, there remain few randomised trials in the field and the disease is uncommon, hence all evidence must be considered weak in comparison with other more common cancers.

Adaptive statistical iterative reconstruction improves image quality without affecting perfusion CT quantitation in primary colorectal cancer.

OBJECTIVES: To determine the effect of Adaptive Statistical Iterative Reconstruction (ASIR) on perfusion CT (pCT) parameter quantitation and image quality in primary colorectal cancer. METHODS: Prospective observational study. Following institutional review board approval and informed consent, 32 patients with colorectal adenocarcinoma underwent pCT (100 kV, 150 mA, 120 s acquisition, axial mode). Tumour regional blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were determined using identical regions-of-interests for ASIR percentages of 0%, 20%, 40%, 60%, 80% and 100%. Image noise, contrast-to-noise ratio (CNR) and pCT parameters were assessed across ASIR percentages. Coefficients of variation (CV), repeated measures analysis of variance (rANOVA) and Spearman' rank order correlation were performed with statistical significance at 5%. RESULTS: With increasing ASIR percentages, image noise decreased by 33% while CNR increased by 61%; peak tumour CNR was greater than 1.5 with 60% ASIR and above. Mean BF, BV, MTT and PS differed by less than 1.8%, 2.9%, 2.5% and 2.6% across ASIR percentages. CV were 4.9%, 4.2%, 3.3% and 7.9%; rANOVA P values: 0.85, 0.62, 0.02 and 0.81 respectively. CONCLUSIONS: ASIR improves image noise and CNR without altering pCT parameters substantially.

The impact of new technology on surgery for colorectal cancer.

Advances in technology continue at a rapid pace and affect all aspects of life, including surgery. We have reviewed some of these advances and the impact they are having on the investigation and management of colorectal cancer. Modern endoscopes, with magnifying, variable stiffness and localisation capabilities are making the primary investigation of colonic cancer easier and more acceptable for patients. Imaging investigations looking at primary, metastatic and recurrent disease are shifting to digital data sets, which can be stored, reviewed remotely, potentially fused with other modalities and reconstructed as 3 dimensional (3D) images for the purposes of advanced diagnostic interpretation and computer assisted surgery. They include virtual colonoscopy, trans-rectal ultrasound, magnetic resonance imaging, positron emission tomography and radioimmunoscintigraphy. Once a colorectal carcinoma is diagnosed, the treatment options available are expanding. Colonic stents are being used to relieve large bowel obstruction, either as a palliative measure or to improve the patient's overall condition before definitive surgery. Transanal endoscopic microsurgery and minimally invasive techniques are being used with similar outcomes and a lower mortality, morbidity and hospital stay than open trans-abdominal surgery. Transanal endoscopic microsurgery allows precise excision of both benign and early malignant lesions in the mid and upper rectum. Survival of patients with inoperable hepatic metastases following radiofrequency ablation is encouraging. Robotics and telemedicine are taking surgery well into the 21(st) century. Artificial neural networks are being developed to enable us to predict the outcome for individual patients. New technology has a major impact on the way we practice surgery for colorectal cancer.

Rapid fibrin D-dimer tests for deep venous thrombosis: factors affecting diagnostic utility.

Measurement of fibrin D-dimer may be a useful diagnostic test to exclude a diagnosis of deep venous thrombosis (DVT) in the emergency department setting. However, the specific assay format may influence its sensitivity and ultimate clinical utility. We tested samples from 200 patients under evaluation for DVT using three fibrin D-dimer assays: the SimpliRED whole blood agglutination assay, a latex agglutination assay, and the Dimertest EIA. Latex agglutination assays were performed in both a specialized laboratory and a routine laboratory. The negative predictive value for all tests was > 90%. The sensitivity of the SimpliRED assay was similar to that of the latex assay. The sensitivity of the latex assay was significantly lower when performed by generalist laboratory technologists. Thus, while D-dimer may be a useful test for the exclusion of DVT, subjective endpoint latex agglutination assays should be performed only by appropriately trained personnel.

[Analgesics; the use of aspirin in dogs; effects of tablet type and food intake on plasma salicylate level]. / Pijnstillers; het gebruik van aspirine bij de hond; invloeden van tablettype en voeropname op de plasma-salicylaatconcentratie.

Administration of acetylsalicylic acid (aspirin) in the dog may cause gastric mucosal damage. Enteric-coated tablets protect the canine stomach during oral aspirin medication. A therapeutic plasma salicylate concentration can be attained using enteric-coated aspirin tablets at a dosage of 25 mg/kg TID. In a series 4 of experiments using adult beagle and large mixed breed dogs and two types enteric-coated tablets, the influence of food intake on the plasma salicylate concentration was studied. Tablets were administered with 8h intervals and food intake was either once daily or three time daily with 8h intervals. Plasma salicylate concentrations were also studied during fasting. It is concluded that, when using enteric-coated tablets, the plasma salicylate concentration in the dog after oral medication is strongly influenced by the aspirin dosage, the tablet type and the feeding pattern. Large enteric-coated tablets may accumulate in the stomach over several days and are not suitable for use in the dog. The gastric accumulation is caused by the enteric-coating of the large tablets and not by the aspirin medication.

Immediate and long-term CT appearances following radiofrequency ablation of renal tumours.

The incidence of renal cell carcinoma is increasing and image-guided radiofrequency ablation (RFA) is emerging as a safe and effective primary treatment. Therefore, it is essential for radiologists to appreciate the varied computed tomography (CT) imaging features following RFA. Prompt recognition of residual or recurrent tumour is crucial in facilitating timely re-treatment where necessary. Conversely, involuting, completely ablated lesions may be mistaken for residual disease. Using examples from experience of treating 105 renal tumours over a 5-year period, the spectrum of post-RFA CT appearances will be illustrated.

Long-term results of percutaneous radiofrequency ablation of unresectable colorectal hepatic metastases: final outcomes.

INTRODUCTION: Percutaneous radiofrequency ablation (PcRFA) provides alternative means of treating patients with unresectable colorectal liver metastases. We previously reported our initial experience in 30 patients treated with PcRFA. We present the final long-term results in these 30 patients. METHODS: The final outcome of the 30 patients treated with PcRFA is reported, 30 months following the initial results published in 2004. RESULTS: Thirty patients (21 males and 9 females), median age 74.5 (44-85) years, underwent PcRFA for 57 lesions in 60 sessions. The final results in this cohort of patients are reported: 28 dead and 2 lost to follow-up. Median follow-up was 22 (3-53) months. Median size was 31 (8-70) mm. Nineteen lesions required repeat PcRFA. Median ablation time per lesion was 12 (4.5-36) min. Eleven patients received chemotherapy pre-PcRFA and 15 received chemotherapy post-PcRFA. Three patients went on to have limited hepatectomies. Complications occurred in 3 (5%) and median hospital stay was 1 (1-7) day. The median hepatic disease-free survival was 12 (95% CI 6.1-17.9) months and actuarial survival was 23.2 (95% CI 18.5-27.8) months. CONCLUSION: PcRFA is safe and associated with increased disease-free and overall survival in patients with unresectable colorectal hepatic metastases.

The clinical utility of spiral CT cholangiography.

Spiral CT cholangiography has received little attention, yet in a single breath-hold spiral and with limited manipulation at the workstation it can yield high resolution images of the biliary tract. In addition it can clearly demonstrate periampullary detail and contribute some dynamic information regarding biliary excretion. The clinical utility of this technique is illustrated and discussed. Breen, D. J., Nicholson, A. A. (2000). Clinical Radiology55, 733-739.

Titanium lines: a manifestation of metallosis and tissue response to titanium alloy megaprostheses at the knee.

Titanium alloy, in its Ti-318 (Ti-A16-V4) format, is a widely used material for orthopaedic implants. However, it has frequently been reported as causing black staining of the periprosthetic tissues as a result of debris from metallic wear. This process of metallosis has been implicated in implant failure. We report three cases in which titanium alloy prostheses for primary bone tumours at the knee have caused the formation of fluid-filled cysts containing metallic debris. The cysts result in radiological appearances which may mimic soft tissue tumour recurrence and also contribute to post-operative failure of the extensor mechanism of the knee.

Fluoroscopically-guided retrieval of ureteric stents.

Percutaneous fluoroscopically-guided retrieval of seven dysfunctional ureteric stents was performed in five patients (four male, one female) over an 18 month period. The technical aspects of the procedure are discussed and the preferred method using rigid forceps is described.

Percutaneous thrombin injection for the treatment of a post-pancreatitis pseudoaneurysm.

Visceral artery pseudoaneurysms are often treated surgically or by transcatheter embolisation. We report a case of a pseudoaneurysm in a patient with chronic pancreatitis, which was successfully occluded by percutaneous injection of thrombin into the pseudoaneurysmal sac as a first-line management.

Invasive aspergilloma of the skull base.

Aspergillus infection originating in the nasal cavity or paranasal sinuses is a rare cause of benign, locally invasive disease affecting the skull base. We describe a case in which extensive disease led to bilateral proptosis and invasion of the anterior cranial fossa.

Blunt bowel and mesenteric injury: diagnostic performance of CT signs.

PURPOSE: Our goal was to determine the sensitivity and specificity of various CT signs of blunt bowel and mesenteric injury. METHOD: The CT findings of 31 patients with blunt abdominal trauma were retrospectively assessed by three observers in consensus. All patients had laparotomy within 24 h of CT. The study group consisted of 19 patients with surgically proven bowel and/or mesenteric injury. The control group consisted of 12 traumatized patients who had no bowel or mesenteric injury. The CT signs assessed were presence, location, and extent of intraperitoneal fluid, extraluminal air, bowel wall thickening, bowel wall discontinuity, mesenteric streaking, and mesenteric hematoma. RESULTS: In the 12 cases of bowel injury (9 transmural injury, 3 partial thickness injury), the CT sign of bowel wall thickening had sensitivity of 50% and specificity of 84% and the CT sign of bowel wall discontinuity had sensitivity of 58% and specificity of 95%. Extraluminal air was a specific but relatively insensitive sign of transmural bowel injury (sensitivity 44%, specificity 100%). In the 13 patients with mesenteric injuries, the CT sign of mesenteric hematoma had sensitivity of 54% and specificity of 94%. Isolated mesenteric streaking was a less specific sign of mesenteric injury (sensitivity 77%, specificity 44%). The finding of peritoneal fluid with no visible solid organ injury was a useful sign of bowel or mesenteric injury, occurring in 11 of 19 (58%) study patients and none of the controls (p < 0.001). CONCLUSION: Bowel wall thickening, bowel wall discontinuity, extraluminal air, and mesenteric hematoma are reasonably specific CT signs of bowel and mesenteric injury following blunt abdominal trauma. The presence of a moderate to large volume of intraperitoneal fluid without visible solid organ injury is an important sign of bowel or mesenteric injury.

Diagnostic accuracy of helical CT for detection of blunt bowel and mesenteric injuries.

OBJECTIVE: To determine the diagnostic accuracy of helical computed tomography (CT) in the detection of blunt bowel and mesenteric injury in a clinical setting. MATERIALS AND METHODS: We evaluated the helical CT and surgical findings in 31 patients with blunt abdominal trauma. Nineteen patients had surgically proven bowel and/or mesenteric injury, and 12 patients had no bowel or mesenteric injury at laparotomy. The CT scans were assessed by three observers in consensus and were graded as showing no injury, minor bowel or mesenteric injury (not requiring urgent surgery), or major bowel or mesenteric injury (requiring immediate surgery). The CT diagnoses were compared with the surgical findings. RESULTS: In the 19 cases of surgically proven bowel injury, CT had an accuracy of 84% (26/31), specificity 84% (16/19), and negative predictive value 89% (16/18) for diagnosis of bowel injury. CT correctly differentiated minor from major bowel injuries in eight of 12 cases (75%). For the 13 cases of mesenteric injury, the accuracy of CT diagnosis was 77% (24/31), specificity 67% (12/18), and negative predictive value 93% (12/13) for diagnosis of mesenteric injury. The CT findings allowed correct differentiation of minor from major mesenteric injuries in seven of 13 cases (54%). CONCLUSION: Helical CT is moderately accurate and has a high negative predictive value in detecting bowel and mesenteric injuries after blunt trauma. Helical CT is not highly accurate in predicting the severity of injury or need for urgent surgery.

Gastric retention of enteric-coated aspirin tablets in beagle dogs.

Administration of acetylsalicylic acid (ASA) in the dog may cause gastric mucosal damage. Enteric-coated tablets protect the canine stomach during oral ASA medication. A therapeutic plasma salicylate concentration can be attained using enteric-coated ASA tablets at a dose rate of 25 mg/kg body wt, administered every 8 h. Six beagle dogs were given enteric-coated ASA tablets (500 mg) orally, in a 5-day cross-over experiment on two different feeding regimens: i.e. feeding once daily (Group I) or 8 hourly (Group II). Results demonstrate that feeding regimen strongly influences the plasma salicylate concentration pattern. Subtherapeutic mean plasma salicylate concentrations were found in both groups. In Group II the standard deviation (SD) of the mean plasma salicylate concentration was larger than that of Group I. The minimal plasma salicylate concentration never reached detectable levels in Group II. In both groups large numbers of tablets were vomited. Gastric evacuation of the ASA tablets is comparable to indigestible solid particles; their removal was dependent on the interdigestive gastric motility. It is concluded that large enteric-coated ASA tablets are not suitable for therapeutic use in small dogs.