In human pregnancy, reduced placental perfusion has been associated with fetal aortic thickening. However, the relative contributions of fetal undernutrition versus fetal underoxygenation to triggering alterations in fetal cardiovascular development remain uncertain. Here, we isolate the effects of chronic fetal hypoxia on fetal cardiovascular development in a specific rodent model of chronic fetal hypoxia independent of changes in nutrition during pregnancy. Pregnant rats were housed under normoxic (21% O2) or hypoxic (13% O2) conditions from day 6 to day 20 of gestation. At day 20, pups and placentas were weighed. Fetal thoraces were fixed for quantitative histological analysis of the aorta. In a separate group, fetal aortic reactivity was assessed via in vitro wire myography. The experiments controlled for sex and within-litter variation. Placental weight was increased and fetal weight maintained in hypoxic pregnancy. Hypoxic pregnancy led to a 176% increment in wall thickness and a 170% increment in the wall-to-lumen area ratio of the fetal aorta. Fetal aortic vascular reactivity was markedly impaired, showing reduced constrictor and relaxant responsiveness in hypoxic pregnancy. Chronic developmental hypoxia independent of changes in nutrition has profound effects on the morphology and function of the fetal aorta in a mammalian species.
Background and Aims: Flexible sigmoidoscopy (FS) increases polyp and carcinoma detection in addition to double contrast barium enema (DCBE). However, CT colonography (CTC) is now the preferred technique. Our aim was to explore whether FS increases polyp and carcinoma detection rates when used in addition to CTC. Methods: Patients who underwent FS and CTC between 2007 and 2009 were included and data were collected from patient records. Yields of polyp, adenoma and carcinoma detection were calculated for FS and CTC. Results: In a cohort of 294 patients, CTC detected 36 patients with carcinomas while FS detected 28. One rectal cancer not seen on CTC was diagnosed by FS. Polyps were seen by CTC in 66 and FS in 45 patients. In 5 patients FS found polyps that were not detected by CTC; 3 of which were small adenomas. FS detected extra adenomas or carcinomas in 1.36% (4/294). Adding FS to CTC neither increased the cancer nor the polyp detection yield significantly. Conclusions: This first study investigating the use of FS in addition to CTC detected little additional pathology. The routine use of FS as a supplement to CTC for adenoma and carcinoma detection is of questionable utility.
IntroductionFlexible sigmoidoscopy (FS) increases the polyp and carcinoma detection yield when used as an addition to double contrast Barium enema.1 The addition of FS to Barium enema has therefore been advised as standard practice.2 CT colonography (CTC) has replaced Barium enemas in many hospitals. We aim to explore whether FS increases the polyp and carcinoma detection yield when used as an addition to CTC.MethodsUsing endoscopy and radiology databases patients who underwent both FS and CTC between 2007 and 2009 were identified. Data were collected from those databases and the electronic patient records. Analysis was based on performed tests regardless of quality of bowel prep (FS and CTC), ability to retain gas (FS and CTC) or extent of procedure (FS). Yields of polyp, adenoma and carcinoma detection were calculated. Serious pathology was defined as cancers and adenomas >9 mm.ResultsA total of 294 patients (179 female; 60.8%), with a mean age of 67 years were included. CTC detected 36 patients with carcinomas while FS detected 26. One rectal cancer not seen on CTC was diagnosed by FS. Polyps were seen by CTC in 71 and by FS in 47 patients. In five patients FS found polyps that were not detected by CTC, 3 of which were small (5 mm) adenomas. FS detected extra adenomas or carcinomas in four of 294 cases, producing a yield of 1.36%. The number needed to endoscope to detect one extra adenoma was 74. Serious additional pathology was detected by FS in a single case, producing a yield of 0.34%. The number needed to endoscope to detect one extra serious pathological finding was 294.ConclusionFS has a low yield of adenomas when used as an additive to CTC. The yield for serious pathology was very small in our series. Based on these findings the usefulness of routine use of FS as a supplement to CTC for adenoma and carcinoma detection is questionable. FS can however provide valuable additional information about inflammation, infection or vascular lesions depending on indication.
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