Required distal mesorectal resection margin in partial mesorectal excision: a systematic review on distal mesorectal spread.

BACKGROUND: The required distal margin in partial mesorectal excision (PME) is controversial. The aim of this systematic review was to determine incidence and distance of distal mesorectal spread (DMS). METHODS: A systematic search was performed using PubMed, Embase and Google Scholar databases. Articles eligible for inclusion were studies reporting on the presence of distal mesorectal spread in patients with rectal cancer who underwent radical resection. RESULTS: Out of 2493 articles, 22 studies with a total of 1921 patients were included, of whom 340 underwent long-course neoadjuvant chemoradiotherapy (CRT). DMS was reported in 207 of 1921 (10.8%) specimens (1.2% in CRT group and 12.8% in non-CRT group), with specified distance of DMS relative to the tumor in 84 (40.6%) of the cases. Mean and median DMS were 20.2 and 20.0 mm, respectively. Distal margins of 40 mm and 30 mm would result in 10% and 32% residual tumor, respectively, which translates into 1% and 4% overall residual cancer risk given 11% incidence of DMS. The maximum reported DMS was 50 mm in 1 of 84 cases. In subgroup analysis, for T3, the mean DMS was 18.8 mm (range 8-40 mm) and 27.2 mm (range 10-40 mm) for T4 rectal cancer. CONCLUSIONS: DMS occurred in 11% of cases, with a maximum of 50 mm in less than 1% of the DMS cases. For PME, substantial overtreatment is present if a distal margin of 5 cm is routinely utilized. Prospective studies evaluating more limited margins based on high-quality preoperative magnetic resonance imaging and pathological assessment are required.

Local recurrence at the site of the Lone Star device through implantation of exfoliated cells during local excision for early rectal cancer: A case report.

INTRODUCTION: Invasive procedures for colorectal cancer can cause iatrogenic tumor cell seeding. Implantation of these exfoliated cells in the surrounding tissue can result in locoregional cancer recurrence. This has been described in endoscopic procedures and major surgical resections, however recurrence in iatrogenic lesions of the anal canal during minimal invasive rectal surgery has not been shown in literature yet. This is the first reported case of recurrent rectal cancer that developed into an anal metastasis at the site where hooks of the Lone Star Retractor disrupted the epithelial lining of the anal canal during a local excision of early rectal cancer using TAMIS. PRESENTATION OF CASE: A 57 year old male was diagnosed with a high risk early stage rectal adenocarcinoma. He was treated with transanal minimally invasive surgery (TAMIS) with the use of a Lone Star retractor and he received subsequent chemo-radiotherapy. 23 months later the patient developed a bleeding mass bulging out of the anus. A true cut and incision biopsy was performed and the pathology report revealed localization of adenocarcinoma at the anal canal which was similar to the earlier diagnosed rectal carcinoma. The patient underwent an abdominal perineal resection and left-sided lymph node dissection. DISCUSSION AND CONCLUSION: This shows that local recurrence through implantation of exfoliated tumor cells can occur in iatrogenic lesions of the anal canal not only in major but also in minimal invasive rectal surgery. Careful tissue handling and rectal washout may reduce the chance of this implantation metastasis.

Single incision laparoscopic approach for infected necrotizing pancreatitis: A case report.

INTRODUCTION: Approximately 5% of patients with acute pancreatitis develop infected necrotizing pancreatitis, with reported mortality rates up to 32%. Surgical interventions are postponed as long as possible, but if surgical debridement is needed the optimal approach has not been found yet. CASE PRESENTATION: A 47-year-old male was referred to our tertiary centre with infected necrotizing pancreatitis. Two months after initial presentation and repeated percutaneous drainage, surgical retroperitoneal debridement of the necrotic tissue was performed using a single incision laparoscopic surgery (SILS) port. Postoperatively, percutaneous drainage was performed two more times, but no additional surgical interventions were needed. The patient was discharged one month after the surgical procedure. DISCUSSION AND CONCLUSION: This is the first report of a minimally invasive technique using a SILS port for debridement of necrotizing pancreatitis. The ability to create a stable pneumo-retroperitoneum leads to optimal visualisation, better haemostasis, more space to operate in, better instrument handling, and better tissue control.

Minimally invasive perineal redo surgery for rectovesical and rectovaginal fistulae: A case series.

INTRODUCTION: Iatrogenic recto-urogenital fistulae are refractory complications that rarely heal without surgical intervention. The ongoing local infection causes pain, discomfort and substantially impacts quality of life. Surgical repair requires adequate exposure and space to fill with healthy tissue, which is a major challenge in pelvic redo surgery. An abdominal approach to repair the fistula is associated with major morbidity and often fails to expose the deep pelvis. In our experience a novel transperineal minimally invasive approach a utilizing single incision laparoscopic surgery (SILS) technique could offer improved results. PRESENTATION OF CASES: In the present study, three cases of patients with recto-urogenital fistulae after pelvic surgery are described. Two patients were diagnosed with a rectovesical fistula and one patient with a rectovaginal fistula. In all three cases, a minimally invasive perineal approach, using a SILS port, was used to perform surgical repair. The closure of the fistulae involved: a separate repair of the urethra/bladder or vaginal defect and the rectal defect, followed by interposition of vascularized tissue by either a pudendal thigh fasciocutaneous flap or omentoplasty. DISCUSSION AND CONCLUSION: This study is the first to report on a minimally invasive perineal approach, utilizing a SILS technique for recto-urogenital fistulae repair after previous pelvic surgery. The current approach improves exposure, creates surgical space, optimizes view and allows the interposition of vascularized tissue, without causing substantial blood loss and avoiding major abdominal surgery.

FSHD associated DNA rearrangements are due to deletions of integral copies of a 3.2 kb tandemly repeated unit.

Facioscapulohumeral muscular dystrophy (FSHD) is a neuromuscular disorder characterized by progressive weakness of the facial, shoulder and upper arm muscles. The disease is associated with DNA rearrangements which are detectable using probe p13E-11 (D4F104S1) in DNA digested with EcoRI or other restriction enzymes. We have cloned and characterized the rearranged EcoRI fragment of four unrelated FSHD patients. Restriction fragment mapping and DNA sequence analysis showed that the proximal and distal parts of the EcoRI fragment, which flank a region of tandemly repeated 3.2 kb units, are identical in normal and rearranged EcoRI fragments. These results strongly support the hypothesis that the FSHD associated rearrangements are due to deletions of integral copies of the 3.2 kb repeated unit. Since these repeated units are likely to form part of the FSHD transcription unit, the variation in repeat unit number might affect the function of the gene product. Hence, our data confine the FSHD gene region and thus provide a starting point for cloning the FSHD gene.

Chromosome 4q DNA rearrangements associated with facioscapulohumeral muscular dystrophy.

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant neuromuscular disorder which maps to chromosome 4qter, distal to the D4S139 locus. The cosmid clone 13E, isolated in a search for homeobox genes, was subsequently mapped to 4q35, also distal to D4S139. A subclone, p13E-11, detects in normal individuals a polymorphic EcoRI fragment usually larger than 28 kilobases (kb). Surprisingly, using the same probe we detected de novo DNA rearrangements, characterized by shorter EcoRI fragments (14-28 kb), in 5 out of 6 new FSHD cases. In 10 Dutch families analysed, a specific shorter fragment between 14-28 kb cosegregates with FSHD. Both observations indicate that FSHD is caused by independent de novo DNA rearrangements in the EcoRI fragment detected by p13E-11.

Optimization of the sensitivity of high-performance liquid chromatography in the detection of heterocyclic aromatic amine mutagens.

Solid-phase extraction with the weak cation-exchange resin Fractogel TSK CM650(S) (TSK CM) was used to optimize the sensitivity and chromatographic resolution by HPLC of the mutagenic heterocyclic aromatic amines MeIQx, 4,8-DiMeIQx, IQ, MeIQ, PhIP, Trp-P-1, Trp-P-2, amino-alpha-carboline and the co-mutagens norharman and harman. The clean-up using cation exchange was applied after purification on Extrelut and propylsulphonic acid-silica gel cartridges (PRS tandem purification). Only the clean-up with TSK CM enabled low detection limits of the mutagenic compounds to be achieved (in the order of ng heterocyclic amines/g experimentally overheated process-flavour sample).

Quantitation of mutagenic/carcinogenic heterocyclic aromatic amines in food products.

A method for screening genotoxic heterocyclic aromatic amines in cooked foods using solid-phase extraction and high-performance liquid chromatography with ultraviolet and fluorescence detection is described. Solid-phase extraction includes basic extraction on diatomaceous earth (Extrelut) and subsequent purification on propylsulphonic acid silica gel. This convenient procedure separates the analytes into a polar group and an apolar group. We have identified the following components in the two groups. The polar group contains aminoimidazoazaarenes i.e. 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline, 2-amino-3-methylimidazo[4,5-f]quinoline, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline, 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine, and glutamic acid pyrolysates, i.e. 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole and 2-aminodipyrido[1,2-a:3',2'-d]-imidazole. The apolar group consists of five carbolines: 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole, 3-amino-1-methyl-5H-pyrido[4,3-b]indole, 2-amino-9H-pyrido[2,3-b]indole, 9H-pyrido[3,4-b]indole and 1-methyl-9H-pyrido[3,4-b]indole. The extraction efficiencies range from 45 to 90%, and the detection limits are in the low nanogram per gram range. The method was applied to the analysis of heterocyclic aromatic amines in pan-fried, oven-cooked and barbecued salmon.

The mutagenicity of edible mushrooms in a histidine-independent bacterial test system.

In mutagenicity screening of 40 edible mushroom species, special attention was paid to the selection of the test system, since complex mixtures such as mushroom extracts may interfere with the genetic endpoint of the assay. This paper shows that the weak mutagenicity of some mushrooms in the Ames test, as reported by several authors, is actually an artefact due to the presence of free histidine in the mushroom extracts, which apparently increases the reversion of bacteria from histidine auxotrophy to prototrophy. To avoid amino-acid interaction, a combination of the forward mutation assay to 8-azaguanine resistance in Salmonella typhimurium TM677 and a liquid test was used. Out of 35 wild and commercially grown mushrooms tested, 13 species exhibited mutagenic activity. In the case of the five samples of dried mushrooms, weak mutagenicity could be detected for Auricularia sp. The presence of microsomal enzymes (S-9) reduced the mutagenic effects of all the mushrooms, with the exception of Agaricus abruptibulbus and Cantharellus cibarius, where metabolic activation enhanced the mutagenic activity.

Formation and action of anticarcinogenic fatty acids.

Conjugated dienoic derivatives of linoleic acid (referred to by the acronym CLA) constitute a newly recognized class of anticarcinogenic fatty acids. Of the eight major CLA isomers, the cis-9, trans-11 isomer alone is incorporated into phospholipid and may be the most biologically relevant isomer. CLA exhibits potent antioxidant activity; evidence is presented indicating that CLA acts both as an in vitro and in vivo antioxidant. The formation of CLA in foods, and its possible biological significance in cell membranes, is discussed.

Antimutagenic effects of mushrooms.

A heat-resistant factor in ethanol extracts of the fungus Craterellus cornucopioides completely inhibited the mutagenicity of aflatoxin B1, benzo[a]pyrene, the acridine half mustard ICR-191 and 2-nitrofluorene in a forward-mutation system using Salmonella typhimurium TM677 (screening for 8-azaguanine resistance). There was no inhibitory effect on the mutagenic activity of 4-nitroquinoline-N-oxide, methyl methanesulfonate or N-methyl-N'-nitro-N-nitrosoguanidine. Experiments performed to elucidate the mechanism of the antimutagenic effect showed that neither an alteration of cell viability nor an interference with the excision-repair and the inducible SOS-repair system was involved. The conceivable mechanisms for the antimutagenicity of the ethanol extract include direct chemical interaction with the mutagen and/or inhibition of the activation process in the case of the promutagens. The antimutagenic activity of Craterellus cornucopioides is not unique among mushroom species. The ethanol extracts of 6 other mushrooms showed a similar antimutagenic activity.