Narito Takada

Renal Tubular Acidosis Secondary to FK506 in Living Donor Liver Transplantation: A Case Report

FK506 is an immunosuppressant that is thought to be less nephrotoxic than cyclosporine A. However, complications due to renal tubular acidosis (RTA) have recently been reported. We report a case of RTA secondary to FK506 administration in liver transplantation. A 6-month-old girl was treated with FK506 after undergoing living donor liver transplantation for fulminant hepatitis. On postoperative day 17, she demonstrated hyperkalaemia and metabolic acidosis; she was diagnosed to have hyperkalaemic distal RTA with aldosterone deficiency (type IV). Intravenous sodium bicarbonate and furosemide, and intrarectal calcium polystyrenesulfonate were administered to correct the acidosis and promote potassium secretion. Thereafter, the FK506 concentration in whole blood gradually decreased, and the hyperkalaemia and metabolic acidosis following RTA improved. RTA is one type of nephrotoxicity induced by FK506, and it is reversible in mild cases when appropriately treated. The mechanism of RTA induced by FK506 has not yet been clearly elucidated. Surgeons and physicians should therefore be aware of the potential for RTA to occur with FK506 after any organ transplantation. The treatment for acidosis and hyperkalaemia should be started as soon as RTA is diagnosed, and the dosage of FK506 should also be reduced if possible.

SAFE TECHNIQUES FOR INSERTING THE HICKMAN CATHETER IN PEDIATRIC PATIENTS

The placement of the Hickman catheter in the central veins is thought to be an effective method for providing venous access in various clinical situations in children. The catheter is usually inserted by the percutaneous approach, but in some cases various troublesome complications can occur, such as sheath introducer kinking or damage, in addition to other major ones. Therefore, some modified techniques, using vascular dilators, both to dilate the route and to avoid such complications, have been developed and investigated to obtain a smooth and safe percutaneous insertion of the Hickman catheter in children. A total of 41 Hickman catheters were inserted by the percutaneous method in 41 pediatric patients from 1996 to 2004 in our department. Sixteen catheters were inserted by means of a standard method, using the manufacturers insertion kit, and 25 catheters were inserted by means of a modified method, namely, using various sized vascular dilators. The length of time for the procedure, the complication rate, and the changes in the serum C-reactive reaction (CRP) levels were then compared between the standard and the modified methods. Those parameters were also compared between a right-side and left-side approach using both methods, to clarify which side was better for the insertion of this catheter. The length of time for the catheter replacement procedure in the standard group was significantly longer than that in modified one. The occurrence rate for both the kinking and small damage to the sheath introducer in the standard group was higher than that in the modified one. The peak of serum CRP in the modified group was significantly lower than that in the standard one. When comparing a right-side and left-side approach, 7 catheters out of 16 were inserted by the right-side approach in the standard group, while 10 catheters out of 25 were done by the right-side approach in the modified group. The length of time for the procedure for the left-side approach was significantly shorter than that for the right-side one in both groups. No difference in technical complications was observed between the two different approaches in the modified group, while complications when using the right-side approach often occurred in the standard group. The peak of serum CRP in the left-side approach was lower than that in the right-side one in both groups. The use of the modified percutaneous method, using various sized vascular dilators and the left-side approach, was therefore found to be useful for the safe and smooth placement of the Hickman catheter in children.

Effect of a valine-rich diet on a rat model of short bowel syndrome

It has been recently reported that valine, which was one of the branched chain amino acids, enhanced liver regeneration after a hepatectomy in rats. The aim of this study is to investigate the effect of enteral valine supplementation on the intestinal adaptation of short bowel syndrome using a rat model. Seven-week-old male Lewis rats underwent a 90% small bowel resection. The rats were randomly divided into two groups; Group V (valine-rich diet which contains valine, five times as the normal amount of valine as that found in standard rat chow) and Group S (standard rat chow), according to the diet each group received. The rats were killed and evaluated at the operative day, and postoperative days (POD) 7, 14, 30, and 60, respectively. The parameters of estimation were body weight (BW), a blood amino acids analysis, a urine organic acids analysis and a morphological examination of the residual small intestines. The BW and the intestinal wet weight, jejunal crypt depth and proliferating cell nuclear antigen positive cells in Group V at POD 7 were significantly higher than in Group S, while those in the Group V at POD 30 and 60 were smaller than in Group S. The urine methylmalonic acid (MMA) level in Group V at POD 30 and 60 was much higher than in Group S. The valine-rich diet was thus found to enhance intestinal regeneration after a small bowel resection in the acute phase. However, the long-term valine-rich diet supplementation was found to disturb the intestinal adaptation, which might be caused by the high production of MMA due to the valine-rich diet. This is the first report in which valine was used as a promoter of intestinal adaptation.