A cw Laser system (Medical Laser Centre Lübeck GmbH, Germany) emitting a wavelength at 1.92μm and a laser power up to 50 W was used for partial porcine renal parenchyma resection and hemi nephrectomy. Laser radiation (30 Watt) was transmitted via 365μm fiber with polished distal fiber tip which was fixed in a stainless steel tube. Power density at the distal fiber tip was 28.6 kW/cm2. On 3 kidneys a partial renal parenchyma resection without opening of the renal pelvis was performed (Group A). On 8 kidneys a hemi nephrectomy with opening of the renal pelvis was performed
(Group B). Total resection time including haemostasis of the remaining tissue was 501 ± 103 s in group "A" and 730 ± 415 s in group "B". Blood lost was 28 ± 3 ml in group "A" and 98 ± 73 ml in group "B". The ischemic time for the kidneys in group "B" was 157 s in average, while for group "A" no ligation was necessary at all. Healing process was observed over 3 weeks, survival rate was 100 %, no inflammation or renal fistulas were found. In conclusion, the first experiments show that the 1.92 μm Laser-System is a very promising device for bloodless and fast kidney resection.
The technique of nephron sparing surgery has matured significantly over the past
decade and is emerging as an oncologically sound procedure for the management of
renal tumors. Methods of tumor excision as well as parenchymal reconstruction in a
hemostaticallly controlled field have evolved to make this procedure safer. In an
attempt to find an improoved hemostatic cutting instrument we developed a 1.94
micrometer Laser-Scalpel system in a porcine model.
We evaluated data for partial porcine kidney resection performed by a 1.94
micrometer Laser-Scalpel and compared the data to those of a standard HF- (High-
Frequency) dissection device. In 12 pigs general anesthesia and a median
laparotomy was performed to expose both kidneys. In each pig one kidney was
partially resected with the Laser-Scalpel and the other side with the HF-dissection
device. The first 6 pigs were euthanized immediately after the procedure. The
following 6 pigs were allowed to recover and underwent 2-3 weeks later euthanasia.
The final evaluation data included total resection time, blood loss, mass of dissected
tissue, total ischemic time and histological examination.
Mean resected kidney tissue mass was 4.75 g with the laser system and 5.57 g for
the HF-dissector, respectively. Mean estimated blood loss was 22 ml for the Laser-
Scalpel and 78.2 ml for the HF-dissection device. Resection time was 9.45 min for the Laser-scalpel compared to 10.16 min. No complications, specifically no
postoperative bleeding, occured in any of the animals. Histological evaluation with
H&E staining showed a carbonized zone of about 0.57 mm directly at the dissected
edge followed by a thermal damaged zone of about 1.25 mm in width. Thereafter
healthy tissue was found in all histological samples.
Partial kidney resection was easily and fast performed by the use of a 1.94
micrometer Laser-Scalpel system. Hemostasis was highly sufficient, so blood loss
was minimal compared to conventional HF-dissection device. Therefore the 1.94
micrometer Laser-Scalpel system is a very promising dissection device for urological
A 1.94 μm Laser-Scalpel system (Starmedtec, Starnberg, Germany) emitting at a wavelength at 1.94 μm and a max. laser
power 18 W (cw mode) was used for partial resection of porcine kidney. Partial resection was performed on 9 kidneys.
Six kidneys were extracted directly after resection and pigs were sacrificed. The remaining three pigs were kept alive for
2 weeks post resection in order to investigate the healing process. No complications during the operation and during the 2
weeks survival period were found. Total resection time including haemostasis of the remaining tissue was 10.2±6.5 min,
blood lost was 14.7±29 ml. Haemostatic property of the 1.94 μm Laser-Scalpel was sufficient. Histological evaluation
with H&E stained tissue samples showed medium carbonization and a thermal damage zone of 1mm. In conclusion, the
first experiments show that the 1.94 μm Laser-Scalpel is a very promising device for bloodless and fast kidney resection.