Kock pouch dysfunction during pregnancy. Management of a case.

The Kock continent ileostomy is a surgical alternative to a Brooke ileostomy after total proctocolectomy. Complications resulting from an improperly functioning nipple valve are not infrequent and when they occur most often require surgical revision. A 19-year-old female with a functioning Kock pouch of 4 years presented at 6 months of pregnancy with complete bowel obstruction due to nipple valve dysfunction. Operative management was avoided and her bowel obstruction was relieved by endoscopic placement of a stent through the nipple valve and into the abdominal reservoir. The stent was removed at 1 week postpartum with immediate return to normal function of her Kock pouch nipple valve. Temporary malfunction of the Kock pouch nipple valve can occur during pregnancy, probably due to distortion of the valve mechanism by the enlarging uterus. The endoscopic placement of a stent can maintain proper bowel evacuation until delivery and normal Kock pouch function can be expected after stent removal.

Phosphorus-31 NMR studies of stabilized phosphorus ylids in the solid state.

Phosphorus-31 powder NMR spectra and high-resolution MAS spectra have been obtained for a number of stabilized phosphorus ylids under conditions of high-power proton decoupling and cross-polarization. The 31P CP/MAS spectra are compared to those obtained from isotropic solutions. The variation of chemical shift anisotropy and of the principal components of the 31P chemical shift tensor determined from 31P powder NMR line shapes are discussed in terms of the relative importance of accepted valence bond resonance structures. The results indicate that the invariance of the isotropic chemical shift, delta iso, observed in previous 31P NMR investigations of phosphorus ylids in solution is due to fortuitous cancellation of opposing changes in the principal components, delta 11 and delta 33, of the 31P chemical shift tensor. The 31P dipolar NMR powder spectrum of a typical stabilized ylid, (C6H5)3(31)P-13CHC(O)OCH2CH3, is analyzed in order to obtain the orientation of the 31P chemical shift tensor with respect to the 31P-13C alpha dipolar vector.