Hand-Assisted Laparoscopic Donor Nephrectomy: Analysis of the Learning Curve in a Training Model In Vivo

Evaluating the differences in the early laparoscopic donor nephrectomy learning curves of a Swiss high volume transplant program and a South African low volume transplant program after knowledge transfer

Background

To describe the retroperitoneoscopic donor nephrectomy learning curve differences between a high volume (training) hospital in Basel, Switzerland, and a low volume (trainee) hospital in Cape Town, South Africa, after knowledge transfer. The South African hospital is resource constraint in hospital and training equipment. Techniques for performing the surgery were near identical.

Methods

Both units maintained prospective databases. Comparisons were made of the first 74 cases in each database: Basel’s series were from 19 January 2001 until 28 June 2004, while the Cape Town Hospital were from 8 April 2008 until 15 July 2008. Four surgeons operated in the Basel group, while only one surgeon operated in the Cape Town group. Variables compared include operating time (first skin incision until kidney was extracted), warm ischaemic time (renal arterial occlusion until cold bench reperfusion), blood loss, graft function, and hospital stay. We also analysed the first and last 25 cases of each series. Subgroup analysis of a single Basel surgeon was conducted.

Results

Donor age (means: Basel vs. Cape Town 54 vs. 33 p < 0.0001) and gender (males vs. females Cape Town 57% male and Basel 31% male) differed widely. The Basel group did more left-sided operations (72% vs. 58%). Operative times, blood loss and donor creatinine did not differ. Warm ischaemic time was significantly shorter in the Basel group (Cape Town mean 204 s Basel mean 130 s P = 0.0023). There was double the number of early graft failures in the South African group (six vs. three)—not related to donor surgery. Both groups showed a decline in operating times, plateauing at 30–34 cases.

Conclusions

There are statistically significant differences in some aspects of the learning curves of the Swiss (training) and South African (trainee) hospitals. These differences are clinically not pronounced, and the knowledge transfer was worth the effort.

Post-mortem Reperfusion of a Pig: a First Step to a New Surgical Training Model?

The purpose of this experimental study was to establish a short-term post-mortem circulation in a pig model using liquid paraffin. This study also investigated the quality of vascular perfusion in the peripheral tissues. This is the first step in the development of a new revascularized human surgical training model. This first experience was performed on the hind leg of a pig. Initial cannulation of the external iliac artery and vein was followed by connection of the arterial inflow to a heart-lung machine and using the venous outflow to flush post-mortem clots and blood. Subsequently, after connecting the venous outflow to the heart-lung machine, circulation was initiated. Circulation was established during 27 min, during which the flow was constantly 130 mL/min. A steady increase in inlet pressure was observed during the experiment, which finally reached a minimum value of 124 mmHg. Perfusion was interrupted early due to an uncontrollable fluid leak. Afterwards, the distal hind leg was incised showing an equal distribution of paraffin. A short-term revascularization was successfully re-established under excellent conditions. Although the results are promising, further experiments are necessary to eventually perform a wide range of surgical procedures on revascularized human cadavers.

Postmortem pump-driven reperfusion of the vascular system of porcine lungs: towards a new model for surgical training

PURPOSE

The objective of this experiment is to establish a continuous postmortem circulation in the vascular system of porcine lungs and to evaluate the pulmonary distribution of the perfusate. This research is performed in the bigger scope of a revascularization project of Thiel embalmed specimens. This technique enables teaching anatomy, practicing surgical procedures and doing research under lifelike circumstances.

METHODS

After cannulation of the pulmonary trunk and the left atrium, the vascular system was flushed with paraffinum perliquidum (PP) through a heart-lung machine. A continuous circulation was then established using red PP, during which perfusion parameters were measured. The distribution of contrast-containing PP in the pulmonary circulation was visualized on computed tomography. Finally, the amount of leak from the vascular system was calculated.

RESULTS

A reperfusion of the vascular system was initiated for 37 min. The flow rate ranged between 80 and 130 ml/min throughout the experiment with acceptable perfusion pressures (range: 37-78 mm Hg). Computed tomography imaging and 3D reconstruction revealed a diffuse vascular distribution of PP and a decreasing vascularization ratio in cranial direction. A self-limiting leak (i.e. 66.8% of the circulating volume) towards the tracheobronchial tree due to vessel rupture was also measured.

CONCLUSIONS

PP enables circulation in an isolated porcine lung model with an acceptable pressure-flow relationship resulting in an excellent recruitment of the vascular system. Despite these promising results, rupture of vessel walls may cause leaks. Further exploration of the perfusion capacities of PP in other organs is necessary. Eventually, this could lead to the development of reperfused Thiel embalmed human bodies, which have several applications.