Colonic perianastomotic carcinogenesis in an experimental model

Background To examine the effect of anastomosis on experimental carcinogenesis in the colon of rats. Methods Forty-three 10-week-old male and female Sprague-Dawley rats were operated on by performing an end-to-side ileorectostomy. Group A:16 rats received no treatment. Group B: 27 rats received 18 subcutaneous injections weekly at a dose of 21 mg/kg wt of 1–2 dimethylhydrazine (DMH), from the eighth day after the intervention. Animals were sacrificed between 25–27 weeks. The number of tumours, their localization, size and microscopic characteristics were recorded. A paired chi-squared analysis was performed comparing tumoral induction in the perianastomotic zone with the rest of colon with faeces. Results No tumours appeared in the dimethylhydrazine-free group. The percentage tumoral area was greater in the perianastomotic zone compared to tumours which had developed in the rest of colon with faeces (p = 0.014). Conclusion We found a cocarcinogenic effect due to the creation of an anastomosis, when using an experimental model of colonic carcinogenesis induced by DMH in rats.

Human cytomegalovirus induced pseudotumor of upper gastrointestinal tract mucosa: Effects of long-term chronic disease?

Human cytomegalovirus-induced lesions resembling malignancies have been described in the gastrointestinal tract and include ulcerated or exophytic large masses. The aim of this study was to review the cases registered in the databases of two academic hospitals and formulate a hypothesis concerning the pathogenic mechanisms responsible for cytomegalovirus-induced pseudotumor development. All the diagnoses of human cytomegalovirus infections of the upper gastrointestinal tract recorded from 1991 to 2013 were reviewed. Cases of mucosal alterations misdiagnosed endoscopically as malignancies were selected. Large ulcers occurring in the stomach (three cases) and an irregular exophytic mass at the gastro-jejunal anastomosis were misdiagnosed endoscopically as malignancies (4 cases out of 53). Histologically, all lesions reflected hyperplastic mucosal changes with a prevalence of epithelial and stroma infected cells, without signs of cell atypia. The hypothesis presented is that the development of human cytomegalovirus-induced pseudotumors may be the morphological expression of chronic mucosa damage underlying long-term infection.

Pontages veineux in situ. Indications, technique et résultats. A propos d'une étude prospective de 26 cas consécutifs [In situ venous grafts. Indications, technique and results. Prospective study of 26 consecutive cases].

The in situ saphenous vein bypass has been introduced in our department since 1989. A total of 26 bypasses in 22 patients have been followed prospectively. Indications for revascularisation have been severe arterial insufficiency in 73% of the cases (stage III or IV). With the exception of one postoperative death (myocardial infarction), all the patients have recovered uneventfully, with a regression to stage I. No amputation has been necessary. Morbidity has been 30%, with mainly minor local complications. The primary patency rate is 83% at one year and 78% after 2 and 3 years, whereas the secondary patency rate is 91% at one year, and remains constant thereafter up to 3 years. Considering our results and those from the literature, we believe that the in situ technique is very valuable, especially for below-knee vascular reconstruction. Technical difficulties of the method are analysed.

Place actuelle de la papillotomie chirurgicale transduodénale [Current status of surgical transduodenal papillotomy].

The treatment of biliary lithiasis has changed during the past 20 years. Cholecystectomy remains the gold standard for cholelithiasis, but many options are available for calculi of the common bile duct. Among them are surgical open or laparoscopic choledochotomy, biliary-enteric anastomosis, transduodenal sphincterotomy (TDS), endoscopic sphincterotomy. With the aim to describe the current place of TDS, we reviewed the patients operated on in our department between 1976 and 1992. We found 78 patients with a mean age of 58 years (26-89 years). 34 (43%) of them had acute cholecystitis, with 26 being operated on urgently. 47 (60%) were jaundiced, 15 (19%) had pancreatitis and 12 (15%) had cholangitis before operation. Indications for TDS have been impacted stone or absence of progression of the contrast medium on intraoperative cholangiography in 71 patients (91%). 3 patients died (1 pulmonary embolism, 1 sepsis of pulmonary origin, 1 MOF syndrome complicating preoperative necrotizing pancreatitis). 30 patients (38%) had complications, of which 20 were directly related to TDS. Hemorrhage occurred in 4 cases, and resolved spontaneously without transfusion. Hyperamylasemia occurred in 17 instances, but clinical pancreatitis developed in only 1 case, with complete resolution. 1 duodenal fistula healed after conservative therapy. No death is attributable directly to TDS. Today, the importance of endoscopic sphincterotomy is increasing. This retrospective study shows that TDS, if performed with caution, does not increase the operative risks even in emergent operations. During surgical exploration of the common bile duct, TDS is indicated to remove an impacted stone, or as a bilio-enteric anastomosis if multiple stones are present with a thin common duct.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluid dynamics simulation of right ventricular outflow tract oversizing.

OBJECTIVES: Repair of the right ventricular outflow tract (RVOT) in paediatric cardiac surgery remains challenging due to the high reoperation rate. Intimal hyperplasia and consequent arteriosclerosis is one of the most important limitation factors for graft durability. Since local shear stress and pressure are predictive elements for intimal hyperplasia and wall degeneration, we sought to determine in an oversized 12-mm RVOT model, with computed fluid dynamics simulation, the local haemodynamical factors that may explain intimal hyperplasia. This was done with the aim of identifying the optimal degree of oversizing for a 12-mm native RVOT. METHODS: Twenty domestic pigs, with a weight of 24.6 ± 0.89 kg and a native RVOT diameter of 12 ± 1.7 mm, had valve conduits of 12, 16, 18 and 20 mm implanted. Pressure and flow were measured at 75, 100 and 125% of normal flow at RVOT at the pulmonary artery, pulmonary artery bifurcation and at the left and right pulmonary arteries. Three-dimensional computed fluid dynamics (CFD) simulation in all four geometries in all flow modalities was performed. Local shear stress and pressure conditions were investigated. RESULTS: Corresponding to 75, 100 and 125% of steady-state flow, three inlet velocity profiles were obtained, 0.2, 0.29 and 0.36 m/s, respectively. At inflow velocity profiles, low shear stress areas, ranged from 0 to 2 Pa, combined with high-pressure areas ranging from 11.5 to 12.1 mmHg that were found at distal anastomosis, at bifurcation and at the ostia of the left and right pulmonary arteries in all geometries. CONCLUSIONS: In all three oversized geometries, the local reparation of shear stress and pressure in the 16-mm model showed a similar local profile as in the native 12 mm RVOT. According to these findings, we suggest oversizing the natural 12-mm RVOT by not more than 4 mm. The elements responsible for wall degeneration and intimal hyperplasia remain very similar to the conditions present in native RVOT.

Postsurgical Prophylaxis in Crohn's Disease: Which Patients, Which Agents?

NlmCategory="UNASSIGNED">Crohn's disease (CD) evolution is characterized by increasing proportions of patients developing complications such as strictures, abscesses and fistulas that require surgical management. After resection of a diseased intestinal segment, CD recurrence concerns up to 60% of patients within a year post surgery. The mucosa just above the site of the intestinal anastomosis is at particularly high risk of relapse. Prophylactic medical therapy to prevent recurrence has been shown to be effective with a variety of medications, but the recurrence rate remains high, demanding that a better risk stratification of patients be achieved. Recognized risk factors for postsurgical CD recurrence include young age at diagnosis and at surgery, smoking, need for repeated surgeries and penetrating disease. These patients require full dose immunosuppressive or anti-tumor necrosis factor (anti-TNF) therapy, which should be initiated in the immediate postoperative period, to prevent the onset of an inflammatory activity in the bowel. Systematic follow-up by endoscopy to monitor treatment benefit should also be part of the management, as endoscopic recurrence heralds clinical relapse in these patients. The role of noninvasive markers of mucosal inflammation, such as stool calprotectin levels, show promise to complete this monitoring. Although the efficacy of mesalazine and imidazole antibiotics has been long recognized, more aggressive approaches, such as thiopurines and anti-TNF antibodies, have shown higher efficacies in direct comparison trials. The potential place of anti-homing agents is not yet defined, but these agents should in principle be of interest for this prophylactic indication due to their mode of action and interesting side-effect profile. The current recommendations are based on a step-up approach that includes immunosuppressors and/or imidazole antibiotics, followed by an anti-TNF agent, such as infliximab and adalimumab, both already tested in randomized trials in this indication. When endoscopic recurrence is identified during follow-up, upscaling to anti-TNF or dose escalation is advocated.

Editorial: Serial Fecal Calprotectin and Lactoferrin Measurements for Early Diagnosis of Pouchitis After Proctocolectomy for Ulcerative Colitis: Is Pouchoscopy No Longer Needed?

This editorial discusses the role of serial measurements of fecal calprotectin or fecal lactoferrin for the early detection of pouchitis in patients with ulcerative colitis having undergone procto-colectomy with ileo-pouch-anal anastomosis. Furthermore, the role of fecal calprotectin and fecal lactoferrin for the monitoring of pouchitis is highlighted.

Rectal enema is an alternative to full mechanical bowel preparation for primary rectal cancer surgery.

AIM: According to the French GRECCAR III randomized trial, full mechanical bowel preparation (MBP) for rectal surgery decreases the rate of postoperative morbidity, in particular postoperative infectious complications, but MBP is not well tolerated by the patient. The aim of the present study was to determine whether a preoperative rectal enema (RE) might be an alternative to MBP. METHODS: An analysis was performed of 96 matched cohort patients undergoing rectal resection with primary anastomosis and protective ileostomy at two different university teaching hospitals, whose rectal cancer management was comparable except for the choice of preoperative bowel preparation (MBP or RE). Prospective databases were retrospectively analysed. RESULTS: Patients were well matched for age, gender, body mass index and Charlson index. The surgical approach and cancer characteristics (level above anal verge, stage and use of neoadjuvant therapy) were comparable between the two groups. Anastomotic leakage occurred in 10% of patients having MBP and in 8% having RE (P = 1.00). Pelvic abscess formation (6% vs 2%, P = 0.63) and wound infection (8% vs 15%, P = 0.55) were also comparable. Extra-abdominal infection (13% vs 13%, P = 1.00) and non-infectious abdominal complications such as ileus and bleeding (27% and 31%, P = 0.83) were not significantly different. Overall morbidity was comparable in the two groups (50% vs 54%, P = 0.83). CONCLUSION: A simple RE before rectal surgery seems not to be associated with more postoperative infectious complications nor a higher overall morbidity than MBP.

Single Heartstring aortotomy for multiple off-pump venous bypass grafts.

Off-pump coronary bypass grafting may decrease the rate of stroke, due to minimal aortic manipulation. For venous grafts, clampless hemostasis when performing the proximal anastomosis can be achieved using the Heartstring device. We describe a technique using a single device to suture two veins to one aortotomy. This technique requires less space and could be advantageous in very short, small, and calcified aortas. In to our experience, this technique is rapid, simple, easy to reproduce, and cost-saving.

Improving coronary artery bypass graft durability: use of the external saphenous vein graft support.

Coronary bypass grafting remains the best option for patients suffering from multivessel coronary artery disease, and the saphenous vein is used as an additional conduit for multiple complete revascularizations. However, the long-term vein graft durability is poor, with almost 75% of occluded grafts after 10 years. To improve the durability, the concept of an external supportive structure was successfully developed during the last years: the eSVS Mesh device (Kips Bay Medical) is an external support for vein graft made of weft-knitted nitinol wire into a tubular form with an approximate length of 24 cm and available in three diameters (3.5, 4.0 and 4.5 mm). The device is placed over the outer wall of the vein and carefully deployed to cover the full length of the graft. The mesh is flexible for full adaptability to the heart anatomy and is intended to prevent kinking and dilatation of the vein in addition to suppressing the intima hyperplasia induced by the systemic blood pressure. The device is designed to reduce the vein diameter of about 15-20% at most to prevent the vein radial expansion induced by the arterial blood pressure, and the intima hyperplasia leading to the graft failure. We describe the surgical technique for preparing the vein graft with the external saphenous vein graft support (eSVS Mesh) and we share our preliminary clinical results.

Identification of Rhizoctonia solani associated with soybean in Brazil by rDNA-ITS sequences

The aim of this study was to identify isolates of Rhizoctonia solani causing hypocotyl rot and foliar blight in soybean (Glycine max) in Brazil by the nucleotide sequences of ITS-5.8S regions of rDNA. The 5.8S rDNA gene sequence (155 bp) was highly conserved among all isolates but differences in length and nucleotide sequence of the ITS1 and ITS2 regions were observed between soybean isolates and AG testers. The similarity of the nucleotide sequence among AG-1 IA isolates, causing foliar blight, was 95.1-100% and 98.5-100% in the ITS1 and ITS2 regions, respectively. The nucleotide sequence similarity among subgroups IA, IB and IC ranged from 84.3 to 89% in ITS1 and from 93.3 to 95.6% in ITS2. Nucleotide sequence similarity of 99.1% and 99.3-100% for ITS1 and ITS2, respectively, was observed between AG-4 soybean isolates causing hypocotyl rots and the AG-4 HGI tester. The similarity of the nucleotide sequence of the ITS-5.8S rDNA region confirmed that the R. solani Brazilian isolates causing foliar blight are AG-1 IA and isolates causing hypocotyl rot symptoms are AG-4 HGI. The ITS-5.8S rDNA sequence was not determinant for the identification of the AG-2-2 IIIB R. solani soybean isolate.

A novel postharvest rot of okra pods caused by Rhizoctonia solani in Brazil

Okra pods with unusual brown lesions and rot were collected in a local supermarket in Brasília DF. The objective of this paper was to characterize the causal agent, to fulfill Koch's postulates and to determine some conditions conducive to disease. The pathogen was identified as Rhizoctonia solani based on morphological characteristics which fitted the fungus description, such as pale to brown hyphae, with nearly right-angled side branches constricted at the base, hyphal cells 6-10 µm wide with a septum near the base. Five isolates were obtained from infected pods and identified as AG 1-IB anastomosis group. Wounded or unwounded okra pods cv. Santa Cruz 47 were inoculated with mycelium disks of R. solani and kept in humid chambers at 12 ºC or 25 ºC. After seven days at 25 ºC, both wounded and unwounded pods were completely rotted and brown, while those kept at 12 ºC showed small lesions ranging from 0.6 to 1.0 mm only in wounded pods. The pathogen was able to grow in different materials used for assembling crates and packs of horticultural products, such as pinewood, corrugated carton, plastic, Styrofoam and newspaper sheets when kept in humid chambers (24 ºC, 96 % RH). The disease occurrence can be related to careless handling practices and to the transmission of R. solani propagules by infected plant debris or soil particles. This is the first report of Rhizoctonia solani causing postharvest rot in okra pods in Brazil.

Estenose arterial pós-transplante hepático: tratamento com angioplastia transluminal percutânea

Vascular complications after liver transplantation include oclusion or stenosis at the sites of anastomosis in the hepatic artery, portal vein, and vena cava. Balloon angioplasty of these stenosis carries little risk and is a useful procedure for the treatment of these problems. The purpose of this paper was to assess whether percutaneous transluminal angioplasty can help to prolong allograft survival and impruve allograft function in patient with hepatic artery stenosis after liver transplantation. We report a 43-year-old mate with stenosis of hepatic artery anastomosis after liver transplantation. An abrupt elevation of liver enzymes and serum bilirrubin levels was noted on the fifth postoperative month. The patient underwent percutaneous liver biopsy, which revealed important ductal depletion due to hypoperfusion, even though Doppler ultrasound examination demonstrated arterial flow. An angiogram confirmed severe stenosis of the arterial anastomosis with poor intraparenchymal arterial perfusion pattern. In an attempt to preserve the graft, a percutaneous transluminal angioplasty was performed using microballoons mounted on a hydrophylic micro guidewire. Intervention proceeded without complications. Liver enzimes and bilirrubin levels decreased within twenty-four hours of angioplasty. Normal levels were achieved after one week. Seven month after angioplasty, the patient is in a optimal clinical condition with no signs of graft impairment. We conclude that percutaneous transluminal angioplasty of hepatic artery stenosis after liver transplantation is relatively safe and may help decrease allograft loss.

Trombose mesentérica como complicação da colecistectomia videolaparoscópica

Intestinal complications after laparoscopic cholecystectomy are rare and usually caused by direct injury sustained on trocar insertion. However, intestinal ischaemia has been reported as an unusual complication of the pneumoperitoneum. We describe a 55-years-old patient who underwent an uneventful laparoscopic cholecystectomy after an episode of acute cholecystitis. Initial recovery was complicated by development of increasing abdominal pain which led to open laparotomy on day 2. Gangrene of the distal ileum and right-sided colon was detected and small bowel resection with right colectomy and primary anastomosis was performed. Histological examination of the resected ileum showed features of venous hemorragic infarction and trombosis. In view of the proximity of the operation it is assumed that ileal ischaemia was precipitated by carbon dioxide pneumoperitoneum. Some studies have been demonstrated that, within 30 minutes of establishing a pneumoperitoneum at an intraabdominal pressure of 16 mmHg, cardiac output, blood flow in the superior mesenteric artery and portal vein decrease progressively. Carbon dioxide pneumoperitoneum may lead to mechanical compression of the splanchnic veins and mesenteric vasoconstriction as a result of carbon dioxide absortion. The distribution of the ischaemic segment of intestine is also unusual as the most precarious blood supply is traditionally at the splenic flexure of the colon. It has been suggested that intermittent decompression of the abdomen reduces the risk of mesenteric ischaemia during penumoperitoneum especially in patients with predisposing clinical features for arteriosclerosis intestinal. In present patient was observed intestinal venous infarction what remains unclear but we think the carbon dioxide pneumoperitoneum have been related to it.

Prolapso jejunal em gastroenteroanastomose

The autors report a case of jejunal mucosa prolapse after gastroenteroanastomosis, a rare postoperative complication. In the late postcholecistectomy period the patient had persistent vomit. Upper digestive endoscopy (UDE) showed obstruction of the second portion of duodenum, and a gastrojejunal anastomosis was performed. Soon after that, the patient had persistent vomit and upper digestive endoscopy (UDE) showed invagination of the jejunal mucosa. She was reoperated, a Roux Y gastrectomy was performed and the patient had a good evolution. The treatment for this complication is basically surgical, which intends to realieve the obstructive symptomatology.