Background and study aims: Laterally spreading tumors – non granular type (LST-NG) are more often considered
candidates for endoscopic submucosal dissection (ESD) than laterally spreading tumors
– granular type (LST-G), because of their higher potential for submucosal invasion.
However, ESD for LST-NG can be technically difficult. The aim of our study was to
compare our ESD results for LST-NG and for LST-G.
Patients and methods: Ninety-nine LST-NG and 169 LST-G measuring 20 mm in size or more were removed by
ESD. We retrospectively evaluated the clinicopathological features of the tumors and
treatment results (en bloc resection rate, procedure time and speed, rate of use of
ancillary devices, and complication and recurrence rates).
Results: Histopathology revealed that there were more submucosally invasive lesions in the
LST-NG than in the LST-G group (28 % vs. 9 %; P < 0.0001). The en bloc resection rate, en bloc R0 resection rate, and en bloc curative
resection rate of LST-NG were similar to those of LST-G (LST-NG: 99 %, 98 %, and 88 %;
LST-G: 99 %, 98 %, and 91 %). In LST-NG, the median procedure time tended to be longer
(LST-NG: 69 min; LST-G: 60 min) and the median procedure speed was slower (LST-NG:
0.15 cm2 /min; LST-G: 0.25 cm2 /min; P < 0.0001). Use of ancillary devices was higher for LST-NG (38 % vs. 15 % for LST-G;
P < 0.0001), as was the perforation rate (5.1 % vs. 0.6 % for LST-G; P = 0.027). No recurrence was seen in either group.
Conclusions: ESD was an effective treatment method for both LST-NG and LST-G. However, the degree
of technical difficulty appears higher for LST-NG than for LST-G lesions, as shown
by the lower dissection speed and higher perforation rate. ESD for LST-NG should probably
be performed by those with significant experience of colorectal ESD.
References
toyonaga@med.kobe-u.ac.jp
