The perspectives of South African general surgeons regarding their postgraduate training.

Background. There is a perception among general surgeons that there are deficiencies in surgical training in South Africa (SA). Dependence on under-resourced state training institutions possibly plays a role. The opinions of qualified surgeons may make an invaluable contribution in this regard.Objectives. To canvass the perceptions of SA general surgeons regarding certain aspects of their training.Methods. An electronic postal survey was conducted. All general surgeons on the Association of Surgeons of South Africa database were requested to complete a structured questionnaire. Four Likert scale items were interrogated: knowledge acquisition, surgical skill, research, and practice management.Results. Eighty-eight surgeons responded. Knowledge acquisition and surgical skills development were regarded positively, except for a perceived deficiency in availability of newer technologies. Exposure to surgical research was viewed as beneficial and useful. However, the mandatory research project during training was not perceived as useful for current careers. Training in practice management was perceived as severely deficient.Conclusion. This survey highlights positive perceptions of general surgeons regarding the acquisition of knowledge and surgical skills during training in SA, but some negative views emerged regarding research, exposure to newer technology, and especially practice management training.

Effect of flushing of the liver graft upon plasma calcium and magnesium concentrations.

Previous studies of total and ionized calcium in the plasma of liver transplant recipients have been conducted in patients with preexisting liver disease or who received blood transfusion. The intraoperative decline in plasma total and ionized calcium has been attributed to the effects of liver disease and/or the citrate in transfused blood. The present study was conducted in normal porcine recipients of liver stored either with EuroCollins or University of Wisconsin (UW) solution for 6 hr, compared with livers flushed with Ringer's lactate without storage. No blood transfusion was given. Mean total plasma calcium levels declined significantly after storage with UW solution to a nadir approximately 65-70% of preoperative levels. This decline persisted for two to five days. Mean levels of plasma ionized calcium declined lowest after flushing with UW solution but only to 82% of preoperative (NS). There was an increase in plasma total magnesium in the recipients of livers flushed with EuroCollins or UW solutions, which resolved within 30 min and which was probably related to magnesium content of the flushing solution. It is concluded that while the changes in plasma total and ionized calcium are moderate and of little clinical significance, they could be aggravated under clinical conditions by massive blood transfusion. Changes in plasma magnesium seemed to be directly attributable to the magnesium content of flushing solutions but the same relationship did not exist for changes in plasma calcium.

Six-hour porcine liver storage without flushing or perfusion.

Livers from normal porcine donors were preserved by surface cooling only, without flushing or perfusion, for periods up to 24 hr. All recipients of livers stored for 6 hr survived until sacrifice at 7 days. In a separate, similar group, survival up to 21 days was noted. Only 2 of 6 recipients survived after 9-hr liver storage, but one of these lived for greater than 120 days. No animals survived longer than 2 days after transplantation of livers stored for 12 or 24 hr. The changes in plasma levels of aspartate aminotransferase of recipients of 6-hr surface-cooled livers were not significantly different from AST levels of recipients of livers stored in University of Wisconsin or Euro-Collins solution as observed in previous studies in this laboratory. At sacrifice after 7 days, there was no histologic evidence of damage after surface cooling. In the light of recent reports of evidence of endothelial and reticuloendothelial damage caused by flushing solutions, it is suggested that surface cooling of the liver may provide adequate preservation for 6 hr in appropriate circumstances. Further studies will be needed to confirm that this method of preservation is applicable to livers removed from brain-dead donors and that it does not cause endothelial damage.

Heparin as the cause of coagulopathy which may complicate grafting of the liver.

Disposal of heparin is accomplished rapidly by the normal liver, but the effects of ischemia, flushing and hypothermia during hepatic transplantation have not been investigated before. The results of the present study showed that neither laparotomy, hypothermia nor insertion of the portosystemic bypass seemed markedly to affect the coagulation profile, but autograft associated with 30 to 45 minutes of warm ischemia resulted in a twofold prolongation of the t1/2 heparin as calculated from sequential measurements of the activated clotting time. Unexpectedly, the storage of livers for four hours in EuroCollins solutions seemed to result in more rapid disappearance of heparin than in animals after laparotomy. After hepatectomy, the clearance of heparin was delayed for two hours but, thereafter, the slope of the disappearance resembled that in sham operated animals. Autograft and allograft of livers in normal pigs that did not receive transfusion were also associated with changes in fibrinolysis and declining levels of fibrinogen together with severe intraoperative bleeding problems and rapid death on the operating table in 30 per cent of the pigs. While administration of heparin alone did not appear to precipitate these changes, use of the drug after dissection, mobilization and storage of the liver may release other tissue factors that activate fibrinolysis.

Seventy-two-hour preservation of the canine liver by machine perfusion.

The UW solution effectively preserves the dog liver for up to 48 hr by simple cold storage. This solution contains lactobionate as the primary impermeant. Another solution developed for machine perfusion of the kidney is similar to the UW solution but contains gluconate in place of lactobionate. In this study the UW gluconate solution was used for the continuous hypothermic machine perfusion of dog livers for 72 hr. Dog livers were continuously perfused at 5 degrees C through the portal vein at a pressure of 16-18 mm Hg and transplanted. Seven of 8 dogs survived for 7 or more days following orthotopic transplantation. The livers functioned as well as those preserved for 48 hr by cold storage in the UW solution as indicated by various liver-function tests. Successful machine perfusion was only achieved when the perfusate contained a high concentration of potassium (125 mM) but not with a high concentration of sodium (125 mM). This study demonstrates the feasibility of machine-perfusion preservation of the liver that yields longer preservation of equal quality compared to simple cold storage. For the development of truly long-term preservation (5 or more days) and better quality short-term preservation, machine perfusion may be the method of choice.

Revised method of orthotopic hepatic transplantation in canines.

Experimental transplantation of the liver is a complex procedure, and technical considerations can often complicate the interpretation of results from studies of hepatic preservation. Improvement in experimental transplantation techniques will decrease adverse effects of the procedure on laboratory animals and assist in the development of improved preservation techniques. The procedure should be designed to mimic the clinical situation. The technique described herein differs from previously described techniques in the operation upon the donor. The bile duct is preserved for anastomosis to the recipient bile duct. The liver is isolated on vascular pedicles, with a new approach to the infrahepatic inferior vena cava, which decreases blood loss. Subdiaphragmatic transection of the suprahepatic inferior vena cava ensures a short segment that cannot twist or telescope into the transplanted liver. The hepatic artery is dissected to the level of the aorta, in contrast with the aorta being used as a conduit. Nonheparinized blood is collected from the hepatic donor. During the operation upon the recipient, the approach to the infrahepatic vena cava minimizes blood loss. A new method of hepaticohepatic arterial anastomosis with preservation of the duodenal blood supply is described. A passive shunt for mesenteric blood flow is used. The bile duct is preserved and choledochocholedochal anastomosis is performed over a stent. The operating time of both harvesting and transplanting was considerably shorter compared with that of reports in the literature and with previous methods used in our laboratory. No dissection of the cold organ was done. There was no incidence of venous outflow obstruction, as previously described. With this technique, blood transfusion of only 1 unit (425 milliliters) resulted in an elevated hemoglobin concentration postoperatively. In 20 consecutive transplants, no failure occurred as a result of technical reasons. This new method appears to simplify the procedure, reduce operating time, is less stressful to the dogs and has produced results superior to those from our previous methods. This method would appear to be easily adaptable to other laboratories interested in hepatic transplantation.