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Scintigraphic reflux studies offer a good screening tool for pharyngeal contamination and aspiration in patients with gastroesophageal reflux disease.

INTRODUCTION The surgical management of symptomatic giant hiatus hernia (GHH) aims to improve quality of life (QoL) and reduce the risk of life threatening complications. Previous reports are predominantly those with small sample sizes and short follow-up periods. The present study sought to assess a large cohort of patients for recurrence and QoL over a longer time period. METHODS This was a follow-up study of a prospectively collected database of 455 consecutive patients. Primary repair of GHH was evaluated by endoscopy/barium meal for recurrence and a standardised symptom questionnaire for QoL. Recurrence was assessed for size, elapsed time, oesophagitis and symptoms. RESULTS Objective and subjective review was achieved in 91.9% and 68.6% of patients. The median age was 69 years (range: 15-93 years) and 64% were female. Laparoscopic repair was completed in 95% (mesh in 6% and Collis gastroplasty in 7%). The 30-day mortality rate was 0.9%. The proportion of patients alive at five and ten years were 90% and 75% respectively. Postoperative QoL scores improved from a mean of 95 to 111 (p<0.01) and were stable over time (112 at 10 years).The overall recurrence rate was 35.6% (149/418) at 42 months; this was 11.5% (48/418) for hernias >2cm and 24.2% (101/418) for <2cm. The rate of new recurrence at 0-1 years was 13.7% (>2cm = 3.4%, <2cm = 10.3%), at 1-5 years it was 30.8% (>2cm = 9.5%, <2cm = 21.3%), at 5-10 years it was 40.1% (>2cm = 13.8%, <2cm = 26.3%) and at over 10 years it was 50.0% (>2cm = 25.0%, <2cm = 25.0%). Recurrence was associated with oesophagitis but not decreased QoL. Revision surgery was required in 4.8% of cases (14.8% with recurrence). There were no interval major GHH complications. CONCLUSIONS Surgery has provided sustained QoL improvements irrespective of recurrence. Recurrence occurred progressively over ten years and may predispose to oesophagitis.

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Spin-polarized density functional theory has been used to investigate the C 2V , C ∞V and D ∞h isomers of the molecules MC 2 , M ) Sc, Y, Tc, and selected states of the diatomic molecule TcC. According to the theory, the ground state of the diatomic is the 4 Σ + TcC isomer. Bond length comparisons between the doublet and quartet isomers reveal the ground state has a double bond, and the first excited state ( 2 ∆ TcC) is triple bonded. For MC 2 , M ) Sc, Y, Tc, numerous minima were located, including spin states of the same symmetry. Cyclic isomers were identified as the ground states for each of the three metals. The minimized C-C bond length for X ˜2A 1 TcC 2 is 1.58 Å, and is close to typical values for carbon-carbon single bonds, whereas the corresponding bond distances in X ˜2A 1 MC 2 , M ) Sc, Y, are closer to typical values for carbon-carbon double bonds. Examination of the isomer structures and energies for TcC 2 suggests a preference for double bond formation with the carbon atoms of the C 2 unit. This is in contrast to scandium and yttrium dicarbides which prefer to form single bonds with the C 2 unit.

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Planar pulmonary scintigraphy is currently the standard investigation for the diagnosis of pulmonary embolism. There are a number of problems with the technique, particularly in patients with an intermediate scan report under the PIOPED criteria. The technique is also under threat from the increasing use of spiral CT angiography. A putative improvement may be gained by use of tomography. The incremental value of tomography over planar studies was therefore evaluated in a virtual model of pulmonary scintigraphy. A model of the segmental anatomy of the lungs was developed from computed tomography, cadaveric human lungs and available anatomical texts. Counts were generated within the phantom by Monte Carlo simulation of photon emission. Eighteen single segmental lesions were interspersed with 47 subsegmental defects and displayed on an Icon reporting station. These were presented in the transaxial, sagittal and coronal planes to four experienced reporters to obtain assessment of defect size. Planar studies of the same defects were displayed to the same observers in the standard eight views with a normal study for comparison. With planar studies, the accuracy of estimation of defect size was 51% compared with 97% using tomographic studies. Defects in the medial basal segment of the right lower lobe were not identified in planar studies but were easily seen by all observers in the tomographic study. It is concluded that there is marked improvement in the accuracy of determination of defect size for tomographic studies over the planar equivalents. This is especially important in the lung bases, the most common reported site of pulmonary emboli. Tomography permits visualisation of defects in the medial basal segment of the right lung, which are not seen in planar studies.