A collaborative EDNAP exercise on SNaPshot™-based mtDNA control region typing.

A collaborative European DNA Profiling (EDNAP) Group exercise was undertaken to assess the performance of an earlier described SNaPshot™-based screening assay (denoted mini-mtSNaPshot) (Weiler et al., 2016) [1] that targets 18 single nucleotide polymorphism (SNP) positions in the mitochondrial (mt) DNA control region and allows for discrimination of major European mtDNA haplogroups. Besides the organising laboratory, 14 forensic genetics laboratories were involved in the analysis of 13 samples, which were centrally prepared and thoroughly tested prior to shipment. The samples had a variable complexity and comprised straightforward single-source samples, samples with dropout or altered peak sizing, a point heteroplasmy and two-component mixtures resulting in one to five bi-allelic calls. The overall success rate in obtaining useful results was high (97.6%) given that some of the participating laboratories had no previous experience with the typing technology and/or mtDNA analysis. The majority of the participants proceeded to haplotype inference to assess the feasibility of assigning a haplogroup and checking phylogenetic consistency when only 18 SNPs are typed. To mimic casework procedures, the participants compared the SNP typing data of all 13 samples to a set of eight mtDNA reference profiles that were described according to standard nomenclature (Parson et al., 2014) [2], and indicated whether these references matched each sample or not. Incorrect scorings were obtained for 2% of the comparisons and derived from a subset of the participants, indicating a need for training and guidelines regarding mini-mtSNaPshot data interpretation.

[Complications after percutaneous transhepatic drainage of the biliary tract]. / Komplikácie po perkutánnych transhepatických drenázach zlcových ciest.

INTRODUCTION: The aim of this work is to demonstrate perioperative and postoperative complications after percutaneous transhepatic drainage of the biliary tract and, on the basis of our own experience, to show the possibilities of solving these complications within hospital care as well as the ways of preventing such complications in outpatient and home care where the role of home care nurses is very important. MATERIAL AND METHODS: At the Department of Radiology in F.D. Roosevelt Teaching Hospital Banska Bystrica, more than 100 percutaenous transhepatic biliary tract drainage procedures are performed every year. In 2013, 105 such procedures were performed. Indications included nonresectable cholangiocarcinomas of the biliary confluence (Klatskin tumours) or common bile duct as well as benign bile obstructions in which endoscopic drainage could not be performed (benign stenosis of thecommon bile duct, stenosis of biliodigestive anastomosis, intrahepatic biliary stones). Between 2009 and 2013, 151 patients with percutaneous transhepatic drainage of the biliary tract were hospitalised at the Department of Surgery in F.D. Roosevelt Hospital Banska Bystrica,of whom 98 had malignant obstruction and 53 benign obstruction. RESULTS: In 151 patients hospitalised at the Department of Surgery, the following postoperative complications occurred: catheter obliteration in 6.6%, biliary peritonitis in 2%, sepsis with cholangitis in 3.3% and haemorrhage in 4.6% of all patients. Mortality directly related to the PTD procedure was 0.66% (1 patient). CONCLUSION: Percutaneous transhepatic biliary tract drainage requires a skilled radiologist who is able to manage all perioperative complications. At the same time, experienced medical staff are needed who are able to treat the drainage catheters correctly and are able to recognize severe complications in time. Complications after PTD occur also during home care of the patients; therefore, cooperation of home care nurses with hospitals where PTD is performed is therefore important. Catheter flushing should be included in the catalogue listing home care procedures.