Endorectal advancement flap for complex anal fistula: does flap configuration matter?

AIM: Treatment of complex anal fistula (CAF) is challenging, often requiring multiple operations due to a high failure rate. The plethora of options attests to the lack of a panacea. Endorectal advancement flap (ERAF) carries the advantages of no sphincter division, no contour defect to the anal canal and no perineal wound. The failure rate of this procedure ranges between 15% and 60%. Although the procedure traditionally described a rhomboid (tongue-shaped) flap, an elliptical (curvilinear) flap was introduced to try to improve the results. This study aimed to describe the elliptical-shaped ERAF performed by the senior authors and others and compare failure rates between elliptical and rhomboid ERAFs for CAF. METHOD: A retrospective review of all patients who underwent ERAF for CAF between 2011 and 2017 was undertaken. Patients were divided into two groups based on the type of flap: rhomboid or elliptical. The main outcomes measures were postoperative persistent or recurrent fistula. RESULTS: Seventy-six ERAF procedures for CAF were identified in 71 patients; 39 had a classic rhomboid flap and 37 had an elliptical configuration with mean follow-up of 13.8 and 13.9 months, respectively. The groups were similar for demographic parameters and preoperative fistula characteristics. The overall failure rate was 37%, with a success rate of 64% in the rhomboid and 62% in the elliptical group. CONCLUSION: The shape of the ERAF for treatment of CAF does not appear to influence failure rate.

Pseudallescheria boydii knee arthritis in a young immunocompetent adult two years after a compound patellar fracture.

Pseudallescheria boydii arthritis of the knee developed in a 32-year-old immunocompetent man 2 years after a compound patellar fracture contaminated with soil. No other potential portal of entry was identified, suggesting that the fungus remained latent for 2 years. Pseudallescheria arthritis often occurs after a prolonged latency period, causing minimal symptoms that contrast with the frequently severe radiological changes. Although this organism often shows limited sensitivity to most antifungal agents, our patient achieved a full recovery after surgical synovectomy and 6 months of itraconazole therapy (400 mg/ d). This case illustrates the importance of testing for fungi in patients with torpid arthritis, particularly when mild clinical symptoms contrast with severe bone and joint destruction.

Effects of starvation on body composition and cold tolerance in the collembolan Orchesella cincta and the isopod Porcellio scaber.

The effects of long-term starvation on the body composition of the isopod Porcellio scaber (Latreille) and the collembolan Orchesella cincta (L.) were studied, by determining the body composition in starved and fed animals. A period under summer conditions (19 degrees C, 75% RH and L/D 16/8 photoperiod), was followed by a period under winter conditions (5 degrees C, 75% RH and LD 6/18 photoperiod). O. cincta was held under summer conditions for 3weeks, during which its protein and lipid content decreased, while its water content increased. In P. scaber, the same occurred during the 6weeks they were kept under summer conditions. During subsequent weeks under winter conditions, changes in cold tolerance of the animals were investigated. Cold tolerance and haemolymph osmolality were measured once a week. Starved animals had lower cold tolerance than fed ones. For P. scaber a decreased haemolymph osmolality was found in starved animals compared to fed ones. This is assumed to be caused by a combination of the consumption of carbohydrates out of the haemolymph and of protein reserves and the accumulation of body water. O. cincta appeared to be capable of osmoregulation, as haemolymph osmolality did not differ between starved and fed animals, despite differences in body water content. Decreased cold tolerance in starved animals of both species may be caused by increased water content or, more probably, by the decrease in reserves needed to produce cryoprotective substances.

Short-term effects of metals on the filtration rate of the zebra mussel Dreissena polymorpha.

In order to study the short-term ecotoxicity of metals to the freshwater mussel Dreissena polymorpha, the effects of Cu, Zn and Cd on the filtration rate of this mussel were determined in laboratory experiments. Filtration rate was chosen as the endpoint, because it is a sensitive sublethal parameter compared to mortality and it is an important parameter given the ecological role D. polymorpha fulfills. The filtration rate was calculated from the decrease in algal concentration, fed to mussels in aquaria, containing different metal concentrations. The EC50 for Cu (41 microg litre(-1)) was lower than for Cd (388 microg litre(-1)) and Zn (1350 microg litre(-1)). The NOEC(accumulation) for the essential metal Zn was higher than for the essential metal Cu. Cadmium, a non-essential metal, was accumulated at all elevated water concentrations, so the NOEC(accumulation) was the concentration in the control water (<0.2 microg litre(-1)). All (no) effect concentrations found in this study were above the quality criteria set for metal concentrations in Dutch surface water, suggesting that the zebra mussel is sufficiently protected by these quality criteria.

Chronic ecotoxicity of copper and cadmium to the zebra mussel Dreissena polymorpha.

In order to evaluate ecological consequences of the long-term presence of metals in aquatic ecosystems, we investigated the filtration rate and survival of zebra mussels (Dreissena polymorpha) during chronic exposure to Cu and Cd. The filtration rate was measured once a week in laboratory experiments lasting 9-11 weeks. The lowest Cu concentration tested (13 micrograms/L) did not affect the filtration rate and survival of D. polymorpha, but the lowest Cd concentration (9 micrograms/L) did affect the filtration rate, but had no effect on survival. The EC50 for Cd decreased markedly from 388 micrograms/L to 27 micrograms/L when the exposure time was lengthened from 48 hours to 10 weeks. The largest decrease in EC50 for Cd was observed during the first week of exposure. In contrast, the EC50 for Cu did not decrease with increasing exposure time (chronic EC50: 43 micrograms/L). Since the chronic LC50 for Cd was 130 micrograms/L, the filtration rate appeared to be a far more sensitive endpoint for ecotoxicological laboratory experiments than mortality. D. polymorpha was capable of regulating the body concentration of the essential metal Cu at low concentrations in the water (13 micrograms/L). Cd was accumulated at every Cd concentration in the water, suggesting that Cd could not be regulated by D. polymorpha. It is concluded that the relation between short-term and long-term ecotoxicity was different for each metal and could not be predicted from the results of the short-term experiments.