Results-There were significant diVerences (p < 0.05) between the British and American populations from which the STS risk algorithm was derived with respect to most variables. The observed mortality in the British population was 3.7% (65 of 1774). The mean predicted mortality by STS score, PACCN, Parsonnet score, and UK algorithms were 1.1%, 1.6%, 4.6%, and 4.7% respectively. The overall predictive ability of the models as measured by the area under the receiver operating characteristic curve were 0.64, 0.60, 0.73, and 0.75, respectively. Conclusions-There are diVerences between the British and American populations for CABG and the North American algorithms are not useful for predicting mortality in the United Kingdom. The UK Society of Cardiothoracic Surgeons algorithm is the best of the models tested but still only has limited predictive ability. Great care must be exercised when using methods of this type for comparisons of units and surgeons. (Heart 1998;79:350-355)

BACKGROUND: Nutritional complications following surgery for morbid obesity include both vitamin and mineral deficiency. Severe cases of zinc deficiency can lead to alopecia, diarrhea, emotional disorders, weight loss, intercurrent infection, bullous-pustular dermatitis and hypogonadism in males. Hair loss may occur after vertical gastroplasty (VG). METHODS: Diffuse hair loss occurred in 47 out of 130 patients who underwent VG. All patients had been routinely advised to take a multivitamin supplement, but 47 developed hair loss despite taking the supplement. These patients were then prescribed Zinc Sulphate 200 mg three times a day. There was no alteration in the vitamin supplementation. RESULTS: Arrest of hair loss and regrowth occurred in all patients. However, five patients reported recurrence of hair loss after stopping zinc. This loss was reversed within 6 months of recommencing zinc 600 mg daily. Ten control patients had no hair loss after gastrointestinal surgery. CONCLUSION: Significant hair loss occurred in about one-third of patients after VG, and was reversed by zinc supplementation.

A prospective study of biochemical changes after vertical banded gastroplasty for morbid obesity, in 94 patients (10 males and 84 females, ages ranging from 18 to 59 years) has been carried out. Liver function tests and electrolyte estimations were performed preoperatively, during hospitalization for surgery, at 6 weeks and at 6 months postoperatively, and demonstrated no significant changes in liver function in these patients 6 months after surgery. The study concludes that there is no increase in the risk of liver damage or electrolyte disturbance after vertical gastroplasty, but that there may be subtle hepatic changes present as gall bladder disease developed in 18 patients postoperation (19%).