Surveillance imaging for sporadic renal angiomyolipoma less than 40 mm: lessons learnt and recommendations from the experience of a large district general hospital.

Introduction Sporadic renal angiomyolipomas, although benign in natural can cause life-threatening spontaneous haemorrhage. Surveillance of smaller lesions is recommended but there is no guidance on the surveillance interval or modality. Our aim was to study our sporadic angiomyolipoma population to determine the growth rate, factors that were associated with a higher growth rate and design a surveillance programme. Materials and methods All sporadic renal angiomyolipomas diagnosed between September 2009 and March 2015 were included. Patients with a diagnosis of tuberous sclerosis were excluded. Results A total of 217 sporadic renal angiomyolipomas were diagnosed. The median follow-up was 24 months (range 10-118 months). The median size at diagnosis was 9.00 mm with a mean growth rate of 0.13 mm/year (standard deviation 0.88). One hundred and fifty angiomyolipomas (69%) were shown to have negative or zero growth. In the remaining 67, 59 had a growth rate of less than 2.00 mm/year. Size of angiomyolipoma, tumour burden and age were not associated with a higher growth rate on multivariate analysis. Conclusion The majority of sporadic angiomyolipomas are small and do not grow. Our practice is to perform surveillance for those greater than 20 mm, with five-yearly ultrasound scans for 21-29 mm, and two-yearly surveillance for 30-39 mm tumours.

The impact of cardiopulmonary exercise testing on patients over the age of 80 undergoing elective colorectal cancer surgery.

AIM: Advanced age and occult cardiorespiratory disease are associated with increased morbidity and mortality following surgery. Cardiopulmonary exercise testing (CPET) may allow the identification of high-risk patients and facilitate planned postoperative critical care support. The aim of this study was to determine whether preoperative CPET in patients aged over 80 undergoing elective colorectal cancer resection was associated with improved outcome. METHOD: All patients aged 80 years and above undergoing elective colorectal cancer resection between 1 March 2011 and 1 September 2013 were retrospectively analysed. Referral for CPET testing was at the discretion of the operating surgeon. Postoperative critical care unit (CCU) admission was based upon the CPET results. RESULTS: Ninety-four patients were identified, of whom 48 underwent CPET testing. The CPET group were significantly older than the non-CPET group (85 vs 83 years, P = 0.04) and were more likely to have a planned admission to CCU postoperatively (P < 0.0001). Despite the increased use of CCU resources, the overall CCU length of stay (LOS) in the CPET group did not differ from the non-CPET group, but the non-CPET group had a higher proportion of Level-3 care. There were no differences in the incidence of unplanned CCU admission between the CPET and the non-CPET group (P = 0.23). There were no differences in overall LOS between the two groups (P = 0.42). There was no difference in mortality (P = 0.11), overall complications (P = 0.53) or severe complications (P = 0.3). CONCLUSION: Preoperative CPET testing in patients aged over 80 undergoing elective colorectal cancer resection allows identification of higher-risk patients and mitigation of risk by preemptive admission to a CCU. This stratification allows equivalent results to be achieved in high- and low-risk elderly patients undergoing colorectal surgery.

Synchronization and coarsening (without self-organized criticality) in a forest-fire model.

We study the long-time dynamics of a forest-fire model with deterministic tree growth and instantaneous burning of entire forests by stochastic lightning strikes. Asymptotically the system organizes into a coarsening self-similar mosaic of synchronized patches within which trees regrow and burn simultaneously. We show that the average patch length grows linearly with time as t--> infinity. The number density of patches of length L, N(L,t), scales as -2N(L/), and within a mean-field rate equation description we find that this scaling function decays as N(x) approximately e(-1/x) for x-->0, and as e(-x) for x--> infinity. In one dimension, we develop an event-driven cluster algorithm to study the asymptotic behavior of large systems. Our numerical results are consistent with mean-field predictions for patch coarsening.

The dynamics or urban demographic change in Malaysia: an analysis of the 1991 population census.

"This paper examines how and to what extent the three demographic components of urban change, urban reclassification, natural increase and net migration, operated in Malaysia between 1980 and 1991.... Since there is a spatial dimension to urban demographic changes, another emphasis of the paper is to differentiate the areal patterns of such changes. The analysis is conducted at both the national level and sub-national levels." Data are from the Malaysian Department of Statistics. The author finds that "the important role of natural increase in urban population change is remarkable considering that a rapid fertility transition had been unfolding in Malaysia up to the mid-1970s."

Internal migration in a rapidly developing country: the case of Peninsular Malaysia.

"This paper discusses the patterns and trends in internal territorial mobility in Peninsular Malaysia from 1957 [to] the 1980s, focussing specially on the period of the 1980s." Data are from Peninsular Malaysian Labour Force Migration Sample Surveys.