Page 50 - Read Online

Page 4 of 9 Phillips et al. Mini-invasive Surg 2020;4:12 I http://dx.doi.org/10.20517/2574-1225.2020.02

Table 1. Characteristics of study population
Robotic stapler Covidien stapler 1
n = 49 n = 187 P-value
Age, Mean (SD) 67.2 (8.3) 67.0 (9.0) 0.89
Male, (%) 25 (51.0) 77 (41.2) 0.22
Caucasian, (%) 49 (100) 184 (98.4) x
BMI, Mean (SD) 28.4 (6.6) 27.0 (5.8) 0.14
Pack years, Mean (SD) 46.9 (24.6) 43.2 (29.2) 0.47
2
Smoking status , (%)
Never 9 (18.4) 24 (12.8) 0.32
Former 29 (59.2) 120 (64.2) 0.52
Current 11 (22.4) 43 (23.0) 0.94
Pulmonary co-morbidities, (%)
Asthma 7 (14.3) 11 (5.9) 0.05
COPD 14 (28.6) 49 (26.2) 0.74
Pulmonary hypertension 1 (2.0) 2 (1.1) 0.59
Emphysema 1 (2.0) 4 (2.1) 0.97
None 28 (57.1) 120 (64.2) 0.37
Pulmonary function, Mean (SD)
FEV1 (L) 2.24 (0.6) 2.12 (0.7) 0.23
FEV1% predicted 84.2 (16.0) 80.1 (18.3) 0.15
FVC (L) 3.3 (0.9) 3.16 (0.9) 0.25
FVC% predicted 91.2 (17.9) 91.2 (17.2) 1.0
Induction therapy, (%) 5 (10.2) 18 (9.6) 0.90
1 P-values from student’s t-test or chi-square test where appropriate. Classified at time of first consultation with a thoracic surgeon. SD:
2
standard deviation; BMI: body mass index; COPD: chronic obstructive pulmonary disease; FEV1: forced expiratory volume in 1 second;
FVC: forced vital capacity; x: statistics unable to be performed

induction therapy, two required a pulmonary artery plasty, and seven were related to a combination of
adhesions or tumor location that limited safe dissection around critical structures. Table 1 provides a
comparison of the perioperative patient characteristics between the robotic and traditional stapler groups.
There was no difference in demographics between the two groups, with a mean age of 67 in both and most
patients were Caucasian. The robotic stapler group had more patients with a history of asthma, (14.2% vs.
5.9%, P = 0.05), but otherwise did not differ in the presence of other co-morbidities. In addition, there were
no differences in preoperative pulmonary function testing or rate of induction therapy.

Intraoperative characteristics between the two groups are compared in Table 2. Cases that utilized the
robotic stapler had a significantly longer average operative time (224 min vs. 176 min, P < 0.001). Given
that these cases were performed by a surgeon in the first few years of practice, this likely reflects a learning
curve rather than inherent delay with use of the robotic stapler, as evidenced by a significant decrease in
average operative time from 2016-2017 (n = 21) to 2018 (n = 28) (247 min vs. 207 min, respectively; P = 0.01).
There was no difference in the average number of staple loads used per case between the two groups. While
the number of staple loads may seem high, anatomic resection is often preceded by a diagnostic wedge,
which obviously increases the total number of staple loads used. Pathologic staging was similar between
the two groups, although there were significantly more stage IIB cases in the robotic stapler group. There
were no differences in lymph node stations or total lymph nodes collected between groups.

Postoperative outcomes are compared in Table 3. There was no difference in average LOS between the two
groups (median three days for both). Median chest tube duration was two days for both groups, and ~20%
of patients in each group were discharged with a chest tube. The overall postoperative PAL rate was 25.8%
for the entire cohort. Within the robotic stapler group, the PAL rate was 20.4%, compared to 27.3% in the
Covidien stapler group (P = 0.33). In the robotic stapler group, one patient with a PAL underwent a bedside
doxycycline pleurodesis. In the Covidien stapler group, 10 patients underwent a procedure for management
(six had bedside doxycycline pleurodesis, three had endobronchial valves, and one had both bedside