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ENDOUROLOGY
& LAPAROSCOPY
Histological
evaluation of cold versus hot cutting: clinical impact on margin status
for laparoscopic partial nephrectomy
Phillips JM, Narula N, Deane LA, Box GN, Lee HJ, Ornstein DK, McDougall
EM, Clayman RV
Department of Urology, University of California-Irvine, Irvine, California,
USA
J Urol. 2008; 180: 2348-52
- Purpose:
While most laparoscopic nephron sparing surgery is performed using cold
scissors, energy based devices may also be used. A criticism of this
approach has been the potential thermal destruction of the cellular
architecture at the tumor margin, precluding the ability to accurately
determine whether tumor cells are present. We clinically characterized
the histological appearance of tumor margins excised with cold scissors,
and bipolar and ultrasonic shears.
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Materials and Methods:
We evaluated 40 renal mass excisions performed by a total of 3 urologists
at our institution between February 2003 and March 2007. There were
10 bipolar (5 mm LigaSure), 20 ultrasonic (Harmonic Scalpel) and 10
cold excisions. All slides were randomly evaluated twice by a single
pathologist blinded to surgeon and excision method. Histological interpretation
of the margin was scored as clear vs. indeterminate. Variables, including
margin fragmentation, artifact, extravascular blood clot, parenchymal
hemorrhage, capillary congestion and vessel sealing, were assessed and
scored on a scale of 0 to 3, that is 0--none, 1-1% to 25%, 2-26% to
50% and 3--greater than 50%.
-
Results: The
pathologist was able to confidently identify cells at the margin as
being malignant or benign in all cases. Histologically the ultrasonic
scalpel demonstrated increased fragmentation and extravascular blood
clotting compared with those of the other cutting methods (p < 0.025
and < 0.026, respectively). The ultrasonic scalpel also showed increased
artifact depth compared to that of cold cutting (p < 0.001). There
were no statistical differences between the groups regarding margin
artifact, parenchymal hemorrhage or capillary congestion. No statistical
significance was observed in any variables between bipolar and cold
cutting.
-
Conclusions:
Despite some degree of cellular damage the ability to determine whether
cells at the margin were benign or malignant was not affected by using
an energy based bipolar or ultrasonic device.
- Editorial
Comment
Laparoscopic partial nephrectomy remains to be challenging technically
due to reconstructive steps but also oncological principles should be
maintained.
The optimal laparoscopic instrument to excise the renal mass during
laparoscopic partial nephrectomy would be the one that not only precisely
removes the mass but also performs coagulation of renal parenchymal
vessels so bleeding would not be relevant during this procedure.
The dilemma is whether energy could also destroy possible cancer cells
during the excision of the mass, allowing coagulation but not disturbing
the histology so the pathological examination is well evaluated to accurately
grade and stage the tumor and it surgical margins. The authors examined
the preference of 3 surgeons and although the possible artifacts maybe
increased with the harmonic scalpel when compared to “cold”
cut (no energy) and Ligasure, the ultrasonic device did not distorted
the histological sample to evaluate its margin status.
Finally, renal hilar clamping may decrease margin positivity due to
better visualization compared to excision of renal masses with no vascular
control.
Dr.
Fernando J. Kim
Chief of Urology, Denver Health Med. Ctr.
Assistant Professor, Univ. Colorado Health Sci. Ctr.
Denver, Colorado, USA
E-mail: fernando.kim@uchsc.edu |