Robotic-assisted total mesorectal excision (TME) for rectal cancer results in a significantly higher quality of TME specimen compared to the laparoscopic approach—report of a single-center experience

Aim

Robotic surgery allows for a better visualization and more precise dissection especially in the narrow male pelvis and mid and lower third of the rectum. However, superiority to laparoscopic TME has yet to be proven. We therefore analyzed short-term outcomes of laparoscopic and robotic low anterior rectal resection for rectal cancer.

Patients and methods

From 2011 to 2016, 44 robotic (RTME) and 41 laparoscopic (LTME) low anterior rectal resection with total mesorectal excision were performed at a single institution. Specimen quality was assessed and reported by an independent pathologist following international guidelines.

Results

The groups did not differ significantly regarding gender, age, ASA stage, BMI, and distance of the lower tumor margin from the anal verge. More patients in the RTME group underwent preoperative chemoradiation (43.2 vs. 19.5%, p?=?0.019). The quality of the TME specimen was significantly better in the RTME group (complete/nearly complete/incomplete for RTME 97/0/3% and for LTME 78/17/5%, p?=?0.03). The conversion rate tended to be lower in the RTME group (7 vs. 17%, p?=?0.143). There was no difference in CRM positivity between the groups.

Conclusion

Robotic surgery is safe and can improve the quality of TME for rectal cancer compared to laparoscopy. Any effect on long-term survival remains to be established.

     

Detection of genomic deletions of PKP2 in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease that predominantly affects the right ventricle and is associated with ventricular arrhythmias that may lead to sudden cardiac death. Mutations within at least seven separate genes have been identified to cause ARVC, however a genetic culprit remains elusive in approximately 50% of cases. Although negative genetic testing may be secondary to pathogenic mutations within undiscovered genes, an alternative explanation may be the presence of large deletions or duplications involving known genes. These large copy number variants may not be detected with standard clinical genetic testing which is presently limited to direct DNA sequencing. We describe two cases of ARVC possessing large deletions involving plakophilin‐2 (PKP2) identified with microarray analysis and/or multiplex ligation‐dependent probe amplification (MLPA) that would have been classified as genotype negative with standard clinical genetic testing. A deletion of the entire coding region of PKP2 excluding exon 1 was identified in patient 1 and his son. In patient 2, MLPA analysis of PKP2 revealed deletion of the entire gene with subsequent microarray analysis demonstrating a de novo 7.9 Mb deletion of chromosome 12p12.1p11.1. These findings support screening for large copy number variants in clinically suspected ARVC cases without clear disease causing mutations following initial sequencing analysis.     

Acute oral administration of a tyrosine and phenylalanine-free amino acid mixture reduces exercise capacity in the heat

Acute tyrosine administration is associated with increased exercise capacity in the heat. To explore whether reduced plasma tyrosine and phenylalanine (tyrosine precursor) is associated with impaired exercise capacity in the heat, eight healthy, moderately trained male volunteers, unacclimated to exercise in the heat, performed two tests in a crossover design separated by at least 7 days. In a randomised, double-blind fashion, subjects ingested 500 mL flavoured, sugar-free water containing amino acids [(TYR-free; isoleucine 15 g, leucine 22.5 g, valine 17.5 g, lysine 17.5 g, methionine 5 g, threonine 10 g, tryptophan 2.5 g)] to lower the ratio of plasma tyrosine plus phenylalanine:amino acids competing for blood–brain barrier uptake (CAA), a key determinant of brain uptake, or a balanced mixture (BAL; TYR-free plus 12.5 g tyrosine and 12.5 g phenylalanine). One hour later, subjects cycled to exhaustion at 63 ± 5 % $\dot {V}$ O_2peak in 30 °C and 60 % relative humidity. Pre-exercise ratio of plasma tyrosine plus phenylalanine:ΣCAA declined 75 ± 5 % from rest in TYR-free (P < 0.001), but was unchanged in BAL (P = 0.061). Exercise time was shorter in TYR-free (59.8 ± 19.0 min vs. 66.2 ± 16.9 min in TYR-free and BAL respectively; P = 0.036). Heart rate (P = 0.298), core (P = 0.134) and skin (P = 0.384) temperature, RPE (P > 0.05) and thermal sensation (P > 0.05) were similar at exhaustion in both trials. These data indicate that acutely depleting plasma catecholamine precursors:ΣCAA is associated with reduced submaximal exercise capacity in the heat.     

Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects

Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non‐union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty‐four New‐Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:513–520, 2015.     

Exclusion of cardiac myosin heavy chain and actin gene involvement in hypertrophic cardiomyopathy of several French families.

Familial hypertrophic cardiomyopathy (FHC) is characterized by idiopathic myocardial hypertrophy, which often and predominantly involves the interventricular septum. The disease is transmitted as an autosomal dominant trait, and its major risk is sudden death. It was recently demonstrated that this disease is genetically heterogeneous and that in 13 of 18 unrelated families the morbid locus, termed FHC-1, maps to chromosome 14q11-12 in and/or very near the cardiac beta-myosin heavy chain gene. We have performed linkage analysis with five chromosomal markers detecting polymorphisms in either the cardiac beta-myosin heavy chain gene or the cardiac actin gene (located on chromosome 15q) on eight families from different regions of France. We show that 1) it is possible to analyze medium-sized families by using highly informative microsatellite markers located in these genes and 2) the disease is not linked to the two contractile protein genes in any of these families. Moreover, 10-20% of chromosome 14 and 20-40% of chromosome 15 in the vicinity of the respective markers were excluded as possible locations for the morbid locus. These results provide new insights into the identification of the genes responsible for FHC.     

Molecular characterization of human factor XSan Antonio

Enzymatic amplification technique was used to isolate all eight exons and sequences around the splice junctions, putative promoter, and polyadenylation sites of human factor X DNA from a patient with factor X deficiency. Two genetic changes in factor X have been observed in this patient. The patient is most likely a compound heterozygote since there is only 14% activity associated with factor X. A point mutation that resulted in the substitution of cysteine (TGC) for arginine (CGC) at amino acid 366 was found in exon VIII of one allele of the factor X gene. This mutation, which occurs in the catalytic domain, can affect the formation of a disulfide bridge and thus could result in a reduction in factor X activity. Sequencing all the regions revealed a second mutation: a deletion of one nucleotide (TCCT to TCT) in exon VII that would cause a frame shift at amino acid 272 followed by termination. We have also shown that the point mutation in exon VIII creates an ApaL1 restriction site and destroys the HinP1 site. Enzymatic DNA amplification followed by restriction digestion provides a quick, reliable, and sensitive method for carrier detection and antenatal diagnosis in affected kindreds. This is the first characterization of factor X deficiency at the molecular level. We propose to name this mutation Factor XSan Antonio.     

Prevalence of genital papillomavirus infection among women attending a college student health clinic or a sexually transmitted disease clinic

We examined 454 women randomly selected from a Sexually Transmitted Disease (STD) Clinic and 545 consecutive college women undergoing annual examination. Patients were examined for visible genital warts, koilocytes, and human papillomavirus (HPV) antigen on cervical smears and for cervical HPV DNA types 6, 11, 16, 18, and 31. Genital warts were found in 11% of STD Clinic patients and 2% of students (P less than .001). Among those women without genital warts, HPV DNA or antigen was detected in cervical specimens from 10.6% of STD Clinic patients and 11.4% of students (P = .73), with HPV type 16, 18, or 31 being 9.8 times more frequent than cervical HPV 6 or 11 among students and 5.8 times more frequent among STD Clinic patients. Dysplasia was present in 53% of those with HPV type 6 or 11 and in 41% of those with HPV type 16, 18, or 31 DNA.