New technique improves safety of islet cell transplantation
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《英国医生杂志》
Researchers at the University of Minnesota in Minneapolis have reported a new technique for closing the access site after islet cell transplantation into the portal vein of the liver. The new technique is less likely than older techniques to have complications, they told the meeting of the Radiological Society of North America in Chicago on Tuesday where they presented their results.
Dr Saravanan Krishnamoorthy, a resident in radiology at the University of Minnesota Medical Center, said that between January 2002 and March 2005 13 patients with poorly controlled type 1 diabetes received 15 islet cell transplantations through the skin into the portal vein of the liver under local anaesthesia. (Two patients had two procedures.)
The Minnesota team used ultrasound guidance to find the right portal vein, which they accessed in 12 of the procedures, or the left, accessed in three. They were successful on the first access attempt in 10 of the procedures and on the second attempt in four. In one case several attempts were needed.
Their unique "sandwich" technique to close the access site through the skin led to a low rate of complications. A needle and then a catheter were inserted through the skin to the portal vein under ultrasound guidance and the islet cells were infused. The cells lodge in the portal vein and produce insulin. During the procedure portal vein pressure was monitored to make sure that the vein was not occluded.
The site was closed with a sandwich of stainless steel or platinum coils and gel foam, inserted through the catheter, then coils, gel foam, and coils again until closure was completed and the needle and catheter removed. The coils slow down blood flow and the gel foam acts like a plug, Dr Krishnamoorthy said. "You keep doing that until you get to the skin or until bleeding stops," he said.
Implanted cells began producing insulin within days to a month, he said.
The team reported that no portal vein thromboses, haematomas, haemorrhages from the tract, or septicaemia occurred in the 30 days after transplantation and no one died as a result of the procedure.
Dr Krishnamoorthy said the technique made islet cell transplantation a safe and a minimally invasive procedure that could be done as an outpatient procedure. He said the technique might be used for other percutaneous procedures.
Under earlier procedures, Dr Krishnamoorthy said, patients required a mini-laparotomy to expose the portal vein, and a catheter would be inserted by direct visualisation. One of the commonest complications of the open procedure was blood loss from the portal vein. In the Minnesota team抯 study only one patient, who needed several attempts at the procedure, lost blood.
With the open procedure the risks of bleeding and infection were greater, he said, and patients took longer to recover.
Although percutaneous islet cell transplantation is currently experimental, Dr Krishnamoorthy said the sandwich method prevents many of the complications of previous techniques. One month after the procedure, all patients were producing their own insulin without the need for injections, and none experienced any major complication.
After one year nearly three quarters of the patients did not need insulin, he said, although the number needing insulin increased with the time since injection of the islet cells. How long implanted islet cells last and whether patients can have many repeated injections is still unknown, he said.(Janice Hopkins Tanne)
Dr Saravanan Krishnamoorthy, a resident in radiology at the University of Minnesota Medical Center, said that between January 2002 and March 2005 13 patients with poorly controlled type 1 diabetes received 15 islet cell transplantations through the skin into the portal vein of the liver under local anaesthesia. (Two patients had two procedures.)
The Minnesota team used ultrasound guidance to find the right portal vein, which they accessed in 12 of the procedures, or the left, accessed in three. They were successful on the first access attempt in 10 of the procedures and on the second attempt in four. In one case several attempts were needed.
Their unique "sandwich" technique to close the access site through the skin led to a low rate of complications. A needle and then a catheter were inserted through the skin to the portal vein under ultrasound guidance and the islet cells were infused. The cells lodge in the portal vein and produce insulin. During the procedure portal vein pressure was monitored to make sure that the vein was not occluded.
The site was closed with a sandwich of stainless steel or platinum coils and gel foam, inserted through the catheter, then coils, gel foam, and coils again until closure was completed and the needle and catheter removed. The coils slow down blood flow and the gel foam acts like a plug, Dr Krishnamoorthy said. "You keep doing that until you get to the skin or until bleeding stops," he said.
Implanted cells began producing insulin within days to a month, he said.
The team reported that no portal vein thromboses, haematomas, haemorrhages from the tract, or septicaemia occurred in the 30 days after transplantation and no one died as a result of the procedure.
Dr Krishnamoorthy said the technique made islet cell transplantation a safe and a minimally invasive procedure that could be done as an outpatient procedure. He said the technique might be used for other percutaneous procedures.
Under earlier procedures, Dr Krishnamoorthy said, patients required a mini-laparotomy to expose the portal vein, and a catheter would be inserted by direct visualisation. One of the commonest complications of the open procedure was blood loss from the portal vein. In the Minnesota team抯 study only one patient, who needed several attempts at the procedure, lost blood.
With the open procedure the risks of bleeding and infection were greater, he said, and patients took longer to recover.
Although percutaneous islet cell transplantation is currently experimental, Dr Krishnamoorthy said the sandwich method prevents many of the complications of previous techniques. One month after the procedure, all patients were producing their own insulin without the need for injections, and none experienced any major complication.
After one year nearly three quarters of the patients did not need insulin, he said, although the number needing insulin increased with the time since injection of the islet cells. How long implanted islet cells last and whether patients can have many repeated injections is still unknown, he said.(Janice Hopkins Tanne)