CARE Dose 4D combined with sinogram-affirmed iterative reconstruction improved the image quality and reduced the radiation dose in low dose CT of the small intestine.

OBJECTIVE: Multislice computed tomography (MSCT) has been used for diagnosis of small intestinal diseases. However, the radiation dose is a big problem. This study was to investigate whether CARE Dose 4D combined with sinogram-affirmed iterative reconstruction (SAFIRE) can provide better image quality at a lower dose for imaging small intestinal diseases compared to MSCT. METHODS: The noise reduction ability of SAFIRE was assessed by scanning the plain water mold using SOMATOM Definition Flash double-source spiral CT. CT images at each stage of radiography for 239 patients were obtained. The patients were divided into groups A and B were based on different tube voltage and current or the image recombination methods. The images were restructured using with filtered back projection (FBP) and SAFIRE (S1-S5). The contrast noise ratio (CNR), CT Dose index (CTDI), subjective scoring, and objective scoring were compared to obtain the best image and reformation parameters at different stages of CT. RESULTS: Twenty-six restructuring patterns of tube voltage and current were obtained by FBP and SAFIRE. The average radiation dose using CARE Dose 4D combined with SAFIRE (S4-S5) reduced approximately 74.85% compared to conditions where the tube voltage of 100 kV and tube current of 131 mAs for patients with MSCT small intestinal CT enterography at plain CT scan, arterial stage, small intestine, and portal venous phase. The objective and subjective scoring were all significantly different among groups A and B at each stage. CONCLUSIONS: Combination of CARE Dose 4D and SAFIRE is shown to decrease the radiation dose while maintaining image quality.

Outcomes of Iatrogenic Genitourinary Injuries During Colorectal Surgery.

OBJECTIVE: To describe, categorize, and determine the outcomes of repairs of genitourinary (GU) injuries that occur during colorectal surgery. Presently, little is known regarding these injuries or the long-term outcomes of their repair. METHODS: We performed a retrospective review of patients undergoing colorectal surgery between 2003 and 2013 who experienced iatrogenic GU injuries requiring surgical repair. GU repair failures were defined as development of urine leak, urinary fistula, or anastomotic stricture requiring secondary GU intervention. Possible risk factors associated with repair failures were examined and included age, American Society of Anesthesiology score, comorbidities, type of colorectal surgery, radiation, and chemotherapy. RESULTS: Of 42,570 colorectal surgeries performed, 75 GU injuries were identified (0.18%). Mean age was 57.5 years (range, 22-91), and median follow-up was 19.5 months (range, 1-128). Fifty-nine (59/75, 79%) patients required a single GU repair whereas 16 of 75 (21%) patients experienced repair failure requiring additional GU intervention. The most common GU injuries were cystotomy (26/75, 35%), incomplete ureteral transection (22/75, 29%), complete proximal and distal ureteral injuries (13/75, 17%; 11/75, 15%), urethral injury (2/75, 3%), and injury to a pre-existing ileal conduit (1/75, 1). Twenty-seven patients (36%) had prior radiation and 35 patients (47%) had prior chemotherapy. Preoperative radiation and chemotherapy were both associated with failure of the GU repair (P = .003; P = .013). Delayed repair of the GU injury was also associated with repair failure (P = .001). CONCLUSION: Iatrogenic GU injuries during colorectal surgery are rare, affecting only 0.18% of colorectal procedures. Preoperative external beam radiation therapy/chemotherapy and delayed GU repair are associated with worse outcomes of repairs of these injuries.

Factors affecting timing of closure and non-reversal of temporary ileostomies.

BACKGROUND: Although stoma closure is considered a simple surgical intervention, the interval between construction and reversal is often prolonged, and some ileostomies may never be reversed. We evaluated possible predictors for non-reversal and prolonged interval between construction and reversal. MATERIAL AND METHODS: In a cohort study of ileostomy patients treated in a large teaching hospital, we collected data from the surgical complication and enterostomal therapists' registries between January 2001 and December 2011. Parameters responsible for morbidity, mortality, length of stay and time interval between construction and reversal were analysed. RESULTS: Of 485 intentionally temporary ileostomies, 359 were reversed after a median of 5.6 months (IQR 3.8-8.9 months), while 126 (26%) remained permanent. End ileostomy and intra-abdominal abscess independently delayed reversal. Age, end ileostomy, higher body mass index and preoperative radiotherapy were independent factors for non-reversal. Median duration of hospitalisation for reversal was 7.0 days (5-13 days). Morbidity and mortality were 31 and 0.9%, respectively. In 20 patients (5.5%), re-ileostomy was necessary. CONCLUSIONS: A substantial number of ileostomies that are intended to be temporary will never be reversed. If reversed, the interval between construction and reversal is longer than anticipated, while morbidity after reversal and duration of hospitalisation are considerable. Besides a temporary ileostomy, there are two other options: no diversion or a permanent colostomy. Shared decision-making is to be preferred in these situations.

Mechanisms underlying the radioprotective effect of histamine on small intestine.

PURPOSE: To examine the protective effects of histamine on intestinal damage produced by gamma-radiation. MATERIALS AND METHODS: 56 mice were divided into 4 groups. Histamine and Histamine-10 Gy groups received a daily subcutaneous histamine injection (0.1 mg/kg) starting 20 hours before irradiation and continued until the end of the experimental period; the untreated group received saline. Histamine-10 Gy and untreated-10 Gy groups were irradiated with a single dose on whole-body using Cesium-137 source (7 Gy/min) and were sacrificed 3 days after irradiation. Small intestine was removed, fixed and stained with hematoxylin and eosin. The number of intestinal crypts per circumference, and other histological characteristics of intestinal cells were evaluated. We further determined by immunohistochemistry the expression of proliferating cell nuclear antigen (PCNA), Bax, Bcl-2 (pro- and anti-apoptotic protein, respectively), antioxidant enzymes (Superoxide dismutase (SOD), Catalase and Glutathione peroxidase), histamine content and apoptosis by terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate biotin nick end labeling (TUNEL) assay. Cells in the S phase of the cell cycle were identified by immunohistochemical detection of 5-bromo-2'-deoxyuridine (BrdU) incorporation. RESULTS: Histamine treatment reduced mucosal atrophy, edema and preserved villi, crypts and nuclear and cytoplasmic characteristics of small intestine after radiation exposure. Additionally, histamine treatment increased PCNA expression and the BrdU-positive cell number, histamine content, decreased the number of apoptotic cells and significantly increased Catalase and copper-zinc-containing SOD of irradiated mice. CONCLUSIONS: Histamine prevents radiation-induced toxicity by increasing proliferation of damaged intestinal mucosa and suppressing apoptosis that was associated with an increase in SOD and Catalase levels. This effect might be of clinical value in patients undergoing radiotherapy.

Effects of radiation damage on intestinal morphology.

The current flow of papers on intestinal structure, radiation science, and intestinal radiation response is reflected in the contents of this review. Multiparameter findings and changes in compartments, cells, or subcellular structure all contribute to the overall profile of the response. The well-recognized changes in proliferation, vessels, and fibrogenesis are accompanied by alterations in other compartments, such as neuroendocrine or immune components of the intestinal wall. The responses at the molecular level, such as in levels of hormones, cytokines, or neurotransmitters, are of fundamental importance. The intestine responds to localized radiation, or to changes in other organs that influence its structure or function: some structural parameters respond differently to different radiation schedules. Apart from radiation conditions, factors affecting the outcome include the pathophysiology of the irradiated subject and accompanying treatment or intervention. More progress in understanding the overall responses is expected in the next few years.

Stimulation of collagen formation in the intestinal anastomosis by low dose He-Ne laser.

The effect of low dose He-Ne laser on the healing of intestinal anastomosis was studied in the albino rat. A small piece of jejunum was removed from each rat and the ends sutured back with a simple interrupted pattern. In the experimental animal, the anastomosis was irradiated through an optic fiber with a He-Ne laser (1 mW) for 15 minutes whereas in the control animal, the anastomosis was not irradiated. The differences between the two groups were compared by histology, transmission electron microscopy, scanning electron microscopy and autoradiography 3 and 7 days after operation. The laser treated experimental animals demonstrated thicker collagen fibers and an increased quantity of collagen at the junction of the anastomosis compared to control animals. Increased uptake of labelled proline was also evident in the laser treated animals. These observations all point to a possible enhancement of collagen synthesis triggered by laser irradiation.

Immunologically mediated intestinal mastocytosis in Nippostrongylus brasiliensis-infected rats.

To investigate mechanisms of mast-cell proliferation, we have utilized infection of Lewis rats with the intestinal nematode, Nippostrongylus brasiliensis, which induces a pronounced intestinal mast-cell hyperplasia. Adoptive transfer of 2 x 10(8) immune mesenteric lymph node cells (IMLN), collected 14 days post infection with 3000 third stage larvae (L3), into rats concurrently given 3000 L3 hastened the expected intestinal mastocytosis by up to 4-5 days. IMLN exhibited this mastopoietic activity in the presence but not in the absence of concurrent infection. Normal mesenteric lymph node cells did not show similar mastopoietic activity. Intestinal mastocytosis was delayed by sub-lethal irradiation (400 rad) but IMLN reconstituted the mast-cell response of such animals. The mastopoietic activity could not be attributed to worm antigen as antigen administered intravenously had no significant effect on mastocytosis and furthermore, antigen could not be detected in mastopoietically active IMLN suspensions used as a possible antigen source in passive cutaneous anaphylaxis tests. Immune serum (14 days post primary infection with 3000 L3) also hastened mastocytosis in infected rats, whereas normal serum did not. The IMLN may be an enriched source of intestinal mast cell precursors and, in addition, may contain a cell type(s) which regulates the differentiation and proliferation of such precursors.