Comparing Variability in Measurement of Subcutaneous Tumors in Mice Using 3D Thermal Imaging and Calipers.

Repeatable tumor measurements are key to accurately assessing tumor growth and treatment efficacy. A preliminary study that we conducted showed that a novel 3D and thermal imaging system (3D-TI) for measuring subcutaneous tumors in rodents significantly reduced interoperator variability across 3 in vivo efficacy studies. Here we further studied this reduction in interoperator variability across a much larger dataset. A dataset consisting of 6,532 paired 3D-TI and caliper interoperator measurements was obtained from tumor scans and measurements in 27 laboratories across 289 studies, 153 operators, over 20 mouse strains, and 100 cell lines. Interoperator variability in both measurement methods was analyzed using coefficient of variation (CV), intraclass correlation (ICC) analysis, and significance testing. The median 3D-TI CV was significantly lower than the median caliper CV. The effects of large interoperator variability at critical points in the study were also investigated. At stratified randomization, changing the operator performing caliper measurements resulted in a 59% probability that a mouse would be reassigned to a different group. The probability that this would occur when using 3D-TI was significantly lower at 29%. In studies in which a tumor was expected to regress, changing the operator during the study was associated with a tumor volume increase of approximately 500mm³ when using calipers. This change did not occur when using 3D-TI. We conclude that 3D-TI significantly reduces interoperator variability as compared with calipers and can improve reproducibility of in vivo studies across a wide range of mouse strains and cell lines.

Assessing quality of care in oesophago-gastric cancer surgery in Australia.

BACKGROUND: Outcomes of oesophago-gastric cancer are poor and highly variable between centres. It is important that complex multimodal treatments are applied optimally. Low case volumes at Australian centres mean that the analysis of crude outcomes is an inadequate assessment of overall quality of care. Detailed analysis across a range of quality domains offers the opportunity to measure performance. METHODS: We compared data from the UK National Oesophago-gastric Cancer Audit 2010 with the prospective Alfred Hospital oesophago-gastric cancer database. RESULTS: There were 314 Alfred and 17 279 UK patients identified. The volume of patients assessed by the Alfred was equal to the second highest quartile in the UK trust (4-5 new cases per month). Case ascertainment was better, capturing 84% of all oesophago-gastric cancer within the Alfred prospective audit (P < 0.001). The use of staging CT and PET scans was more common among Alfred patients (99% versus 89%, P < 0.01 and 83.8% versus 17%, P < 0.01, respectively). More patients embarked on a curative pathway (P < 0.01), with greater use of neo-adjuvant therapies. Acceptable lymph node yields were less in oesophagectomies (88.2% versus 96.2%, P < 0.01) and similar in gastrectomies (77.4% versus 74.6%, P = 0.61). Higher overall complications were observed in Alfred patients (P < 0.01), predominantly due to respiratory complications. Perioperative mortality after resection and 1-year survival was similar. CONCLUSIONS: Comparing a range of quality domains as a means of identifying areas of deficiency is feasible. This allows for contemporaneous improvements in service quality and may be more appropriate in the Australian setting than focusing on volume.

The Physiology and Pathophysiology of Gastroesophageal Reflux in Patients with Laparoscopic Adjustable Gastric Band.

INTRODUCTION: The effect of the laparoscopic adjustable gastric band (LAGB) on esophageal acid exposure and reflux is poorly understood. Optimal technique and normative values for acid exposure have not been established in this group. METHODS: High-resolution manometry (HRM) and 24-h ambulatory esophageal pH monitoring were performed in three groups: asymptomatic LAGB, symptomatic LAGB, and pre-operative reflux patients. This technique utilized intraluminal pressure signatures during HRM to guide accurate pH sensor placement. RESULTS: The LAGB groups were well matched: age 48 vs 51 years (p = 0.249), weight loss 27.3 vs 26.7 kg (p = 0.911). The symptomatic group had a larger gastric pouch (5.2 vs 3.3 cm, p = 0.012), with higher esophageal acid exposure (10.8 vs 0.9%, p < 0.001). Two acidification patterns were observed: irritant and volume acidification, associated with substantial supine acidification. Symptomatic LAGB had altered esophageal motility, with poorer lower esophageal sphincter basal tone (8.0 vs 17.7 mmHg, p = 0.022) and impaired contractility of the lower esophageal segment (90 vs 40%, p = 0.009). Compared to pre-operative reflux patients, symptomatic LAGB patients demonstrated higher total and supine esophageal acid exposure (10.8 vs 7.0%, p = 0.010; 14.9 vs 5.1%, p < 0.001), less symptoms (2 vs 6, p = 0.001) and lower symptom index (0.7 vs 0.9, p = 0.010). CONCLUSIONS: Ambulatory pH monitoring is an effective technique if the pH sensor is positioned appropriately using HRM. The correctly positioned LAGB appears associated with low esophageal acidification. In contrast, patients with symptoms or pouch dilatation can have markedly elevated esophageal acidification, particularly when supine. This is a different pattern compared to pre-operative patients and importantly can be disproportionate to symptoms.

Small bowel obstruction creates a closed loop in patients with a laparoscopic adjustable gastric band.

We report on two cases of small bowel obstruction in the setting of a previous laparoscopic adjustable gastric band insertion. In both cases, a closed loop obstruction was created by the band and delayed diagnosis resulted in significant morbidity. Early recognition with deflation of the adjustable gastric band and nasogastric tube insertion is paramount to managing these patients.