Ileocecal segment transposition does not alter whole gut transit in humans

In vivo imaging of Zika virus reveals dynamics of viral invasion in immune-sheltered tissues and vertical propagation during pregnancy

Rationale: Zika virus (ZIKV) is a pathogenic virus known to cause a wide range of congenital abnormalities, including microcephaly, Guillain-Barre syndrome, meningoencephalitis, and other neurological complications, in humans. This study investigated the noninvasive detection of ZIKV infection in vivo, which is necessary for elucidating the virus's mechanisms of viral replication and pathogenesis, as well as to accelerate the development of anti-ZIKV therapeutic strategies.

Methods: In this study, a recombinant ZIKV harbouring Nluc gene (ZIKV-Nluc) was designed, recovered, and purified. The levels of bioluminescence were directly correlated with viral loads in vitro and in vivo. The dynamics of ZIKV infection in A129 (interferon (IFN)-α/β receptor deficient), AG6 (IFN-α/β and IFN-γ receptor deficient), and C57BL/6 mice were characterized. Pregnant dams were infected with ZIKV-Nluc at E10 via intra footpad injection. Then, the pooled immune sera (anti-ZIKV neutralizing antibodies) #22-1 in ZIKV-Nluc virus-infected mice were visualized.

Results: ZIKV-Nluc showed a high genetic stability and replicated well in cells with similar properties to the wild-type ZIKV (ZIKVwt). Striking bioluminescence signals were consistently observed in animal organs, including spleen, intestine, testis, uterus/ovary, and kidney. The ileocecal junction was found to be the crucial visceral target. Infection of pregnant dams with ZIKV-Nluc showed that ZIKV was capable of crossing the maternal-fetal barrier to infect the fetuses via vertical transmission. Furthermore, it was visualized that treatment with the pooled immune sera was found to greatly restrict the spread of the ZIKV-Nluc virus in mice.

Conclusions: This study is the first to report the real-time noninvasive tracking of the progression of ZIKV invading immune-sheltered tissues and propagating vertically during pregnancy. The results demonstrate that ZIKV-Nluc represents a powerful tool for the study of the replication, dissemination, pathogenesis, and treatment of ZIKV in vitro and in vivo.

Urinary diversion and bladder reconstruction/replacement using intestinal segments for intractable incontinence or following cystectomy

BACKGROUND

Surgery performed to improve or replace the function of the diseased urinary bladder has been carried out for over a century. Main reasons for improving or replacing the function of the urinary bladder are bladder cancer, neurogenic bladder dysfunction, detrusor overactivity and chronic inflammatory diseases of the bladder (such as interstitial cystitis, tuberculosis and schistosomiasis). There is still much uncertainty about the best surgical approach. Options available at the present time include: (1) conduit diversion (the creation of various intestinal conduits to the skin) or continent diversion (which includes either a rectal reservoir or continent cutaneous diversion), (2) bladder reconstruction and (3) replacement of the bladder with various intestinal segments.

OBJECTIVES

To determine the best way of improving or replacing the function of the lower urinary tract using intestinal segments when the bladder has to be removed or when it has been rendered useless or dangerous by disease.

SEARCH METHODS

We searched the Cochrane Incontinence Group Specialised Trials Register (searched 28 October 2011), which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and CINAHL, and handsearching of journals and conference proceedings, and the reference lists of relevant articles.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials of surgery involving transposition of an intestinal segment into the urinary tract.

DATA COLLECTION AND ANALYSIS

Trials were evaluated for appropriateness for inclusion and for risk of bias by the review authors. Three review authors were involved in the data extraction. Data were combined in a meta-analysis when appropriate.

MAIN RESULTS

Five trials met the inclusion criteria with a total of 355 participants. These trials addressed only five of the 14 comparisons pre-specified in the protocol. One trial reported no statistically significant differences in the incidence of upper urinary tract infection, uretero-intestinal stenosis and renal deterioration in the comparison of continent diversion with conduit diversion. The confidence intervals were all wide, however, and did not rule out important clinical differences. In a second trial, there was no reported difference in the incidence of upper urinary tract infection and uretero-intestinal stenosis when conduit diversions were fashioned from either ileum or colon. A meta-analysis of two trials showed no statistically significant difference in daytime or nocturnal incontinence amongst participants who were randomised to ileocolonic/ileocaecal segment bladder replacement compared to an ileal bladder replacement. However, one small trial suggested that bladder replacement using an ileal segment compared to using an ileocolonic segment may be better in terms of lower rates of nocturnal incontinence. There were no differences in the incidence of dilatation of upper tract, daytime urinary incontinence or wound infection using different intestinal segments for bladder replacement. However the data were reported for 'renal units', but not in a form that allowed appropriate patient-based paired analyses. No statistically significant difference was found in the incidence of renal scarring between anti-refluxing versus freely refluxing uretero-intestinal anastomotic techniques in conduit diversions and bladder replacement groups. Again, the outcome data were not reported as paired analysis or in form to carry out paired analysis.

AUTHORS' CONCLUSIONS

The evidence from the included trials was very limited. Only five studies met the inclusion criteria; these were small, of moderate or poor methodological quality, and reported few of the pre-selected outcome measures. This review did not find any evidence that bladder replacement (orthotopic or continent diversion) was better than conduit diversion following cystectomy for cancer. There was no evidence to suggest that bladder reconstruction was better than conduit diversion for benign disease. The clinical significance of data from one small trial suggesting that bladder replacement using an ileal segment compared to using an ileocolonic segment is better in terms of lower rates of nocturnal incontinence is uncertain. The small amount of usable evidence for this review suggests that collaborative multi centre studies should be organised, using random allocation where possible.

Donor-site morbidity after free ileocolon flap transfer for esophageal and voice reconstruction

BACKGROUND

Radical excision of advanced hypopharyngeal and laryngeal tumors usually compromises both swallowing and speech. Among the available reconstruction methods, the free ileocolon flap allows rehabilitation of both functions in one stage. The donor-site morbidity of this flap has not been addressed in head and neck cancer patients.

METHODS

A retrospective study was conducted in 34 patients between April of 2003 and December of 2007 to investigate donor-site morbidity in patients undergoing reconstruction with free ileocolon flaps. Complications such as diarrhea, upper gastrointestinal tract distress, bowel leak, abscess, or hernia formation were evaluated. Significant association of diarrhea and upper gastrointestinal distress, previous abdominal operations, systemic diseases, primary versus secondary reconstruction, flap length, and postoperative chemotherapy were subsequently evaluated. Differences were considered significant for values of p <or= 0.05.

RESULTS

There were no perioperative or postoperative deaths. Nineteen patients (56 percent) experienced temporary diarrhea. In all but two patients, diarrhea discontinued by 4 months. Chemotherapy was significantly associated with diarrhea (p < 0.01). Colchicine, terbinafine, and heroin withdrawal episodically caused diarrhea but statistical conclusions could not be drawn. Six patients (18 percent) suffered from upper gastrointestinal tract problems (gastroduodenal ulcer, erosive gastritis, and minor bleeding), probably because of insufficient gastric protection.

CONCLUSIONS

The free ileocolon flap proved to be a reliable method when simultaneous restoration of swallowing and speech was required, with donor-site morbidity comparable to that of the other intestinal flaps.

Reliability of the ICRP'S dose coefficients for members of the public: IV. basis of the human alimentary tract model and uncertainties in model predictions

The biokinetic and dosimetric model of the gastrointestinal (GI) tract applied in current documents of the International Commission on Radiological Protection (ICRP) was developed in the mid-1960s. The model was based on features of a reference adult male and was first used by the ICRP in Publication 30, Limits for Intakes of Radionuclides by Workers (Part 1, 1979). In the late 1990s an ICRP task group was appointed to develop a biokinetic and dosimetric model of the alimentary tract that reflects updated information and addresses current needs in radiation protection. The new age-specific and gender-specific model, called the Human Alimentary Tract Model (HATM), has been completed and will replace the GI model of Publication 30 in upcoming ICRP documents. This paper discusses the basis for the structure and parameter values of the HATM, summarises the uncertainties associated with selected features and types of predictions of the HATM and examines the sensitivity of dose estimates to these uncertainties for selected radionuclides. Emphasis is on generic biokinetic features of the HATM, particularly transit times through the lumen of the alimentary tract, but key dosimetric features of the model are outlined, and the sensitivity of tissue dose estimates to uncertainties in dosimetric as well as biokinetic features of the HATM are examined for selected radionuclides.

Urinary diversion and bladder reconstruction/replacement using intestinal segments for intractable incontinence or following cystectomy

BACKGROUND

Surgery performed to improve or replace the function of the diseased urinary bladder has been carried out for over a century. Main reasons for improving or replacing the function of the urinary bladder are bladder cancer, neurogenic bladder dysfunction, detrusor overactivity and chronic inflammatory diseases of the bladder (such as interstitial cystitis, tuberculosis and schistosomiasis). There is still much uncertainty about the best surgical approach. Options available at the present time include: (1) conduit diversion (the creation of various intestinal conduits to the skin) or continent diversion (which includes either a rectal reservoir or continent cutaneous diversion), (2) bladder reconstruction and (3) replacement of the bladder with various intestinal segments.

OBJECTIVES

To determine the best way of improving or replacing the function of the lower urinary tract using intestinal segments when the bladder has to be removed or when it has been rendered useless or dangerous by disease.

SEARCH STRATEGY

We searched the Cochrane Incontinence Group's specialised register (3 May 2001), The Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2001), MEDLINE (1966 to May 2001), PREMEDLINE (4 June 2001), Dissertation Abstracts (18.6.2001) and the reference lists of relevant articles. Date of most recent search: June 2001.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials of surgery involving transposition of an intestinal segment into the urinary tract.

DATA COLLECTION AND ANALYSIS

Trials were evaluated for appropriateness for inclusion and for methodological quality by the reviewers. Three reviewers were involved in the data extraction. The data collected was then analysed for statistical significance.

MAIN RESULTS

Two trials met the inclusion criteria with a total of 164 participants. These trials addressed only four of the 14 comparisons pre-specified in the protocol. There were no statistically significant differences found in the incidence of upper urinary tract infection, ureterointestinal stenosis and renal deterioration in the comparison of continent diversion with conduit diversion. There was no evidence of a difference in incidence of upper urinary tract infection and uretero-intestinal stenosis when conduit diversions were fashioned from either ileum or colon. No statistically significant difference was found in the incidence of renal scarring between anti-refluxing versus freely refluxing uretero-intestinal anastomotic techniques in conduit diversions. The confidence intervals were all wide, however, and did not rule out important differences. There was some limited evidence that use of the more complex nipple valve at the ureteroileal anastomosis was more likely to lead to upper tract deterioration than implantation into a non-detubularised, isoperistaltic ileal afferent limb.

REVIEWER'S CONCLUSIONS

The evidence from the included trials was very limited. Only two studies met the inclusion criteria; these were small, of moderate or poor methodological quality, and reported few of the pre-selected outcome measures. This review did not find any evidence that bladder replacement (orthotopic or continent diversion) was better than conduit diversion following cystectomy for cancer. There was no evidence to suggest that bladder reconstruction was better than conduit diversion for benign disease. The small amount of usable evidence for this review suggests that collaborative multicentre studies should be organised, using random allocation where possible.

Ileocecal valve as substitute for the missing pyloric sphincter after partial distal gastrectomy

OBJECTIVES

Accelerated gastric emptying (including dumping syndrome) occurs frequently after gastric resections, largely resulting from rapid entry of meal contents into the small intestine. The authors hypothesized that an ileocecal segment used as an interpositional graft placed between the remaining part of the stomach and the small intestine would slow down food transit and thus replace pyloric function.

METHODS

Thirty Göttingen minipigs were randomized into three groups. Group 1: partial gastrectomy and Roux-en-Y reconstruction; Group 2: partial gastrectomy and ileocecal interpositional graft; and Group 3: sham laparotomy. Gastric emptying in the nonsedated animals was quantified using radioscintigraphy at 3 and 6 months postoperatively. The animals ingested 300 grams of soft food containing 99mTc labeled resin- pellets using a technique previously described. Data were analyzed using ANOVA.

RESULTS

Three months postoperatively, the ileocecal group had a significantly prolonged gastric emptying time compared with the Roux-en-Y group, but gastric emptying time was also significantly faster compared to the control group (sham laparotomy). After 6 months no significant difference was seen between the ileocecal group and the controls, while emptying rates were still significantly faster in the Roux-en-Y group.

CONCLUSIONS

Reconstruction of the gastric reservoir with an ileocecal segment largely restores gastric emptying patterns of food in minipigs. Six months postoperatively, gastric emptying time is similar to that of controls, and significantly slower when compared with the group with Roux-en-Y reconstruction. These results suggest that the ileocecal interposition graft could offer specific advantages over current reconstruction procedures.

Clinical outcome and quality of life after gastric and distal esophagus replacement with an ileocolon interposition

Mainly because of the loss of reservoir function, loss of sphincter function, and exclusion of the duodenal route, patients who undergo gastrectomy suffer from many adverse effects postoperatively. The ileocecal interpositional graft is an attractive method to use as a gastric substitute after gastrectomy and distal esophagectomy. A pedunculated ileocecal graft is placed between the esophagus and the duodenum. The cecum acts as a reservoir while the ileocecal valve protects against enteroesophageal reflux. The duodenal passage is also preserved. Fourteen patients underwent this operation. The technique-related morbidity was low and the quality of life was good. During a mean follow-up of 6 months, no evidence of severe dumping syndrome or reflux esophagitis was observed. Further prospective randomized studies are warranted to compare this technique with the standard methods of gastric reconstruction.

Surgery of the small intestine

This article reviews both clinical and scientific advances in surgery of the small intestine that have been reported in the last year. The management of both pediatric and adult intussusception is considered. Multiple studies on the evolving role of ileal pouch-anal anastomosis are assessed. The treatment and epidemiology of a wide variety of intestinal neoplasms are reviewed. Advances in small bowel transplantation are also reported. The cause of small bowel obstruction is considered as well as new strategies to prevent adhesion formation. Finally, a number of diverse topics relating to intestinal surgery, including new data on laparoscopic surgery, treatment of enterocutaneous fistulas, reconstruction after total gastrectomy, intestinal transit after ileocecal segment transposition, and ischemia/reperfusion and anastomotic healing, are reviewed.