From October 2012 to January 2019, a total of 112 patients underwent laparoscopic colectomies at Venizeleio General Hospital of Heraklion in Crete (Greece). Patients were formally divided into two groups named as A and B. Group A can be characterised as training group and Group B as post-training group. In Table 1, the demographics of patients -age and sex- are shown. There is no significant difference in patients’ sex between the two groups A and B (p = 0.546) and the age distribution (p = 0.634).
Table 1
Sex and age distribution of patients between the training (A) and post-training group (B)
| Group | p |
Α | Β |
n | % | n | % |
Sex | 1 (n = 48) | 23 | 47.9% | 25 | 52.1% | 0.546 |
2 (n = 64) | 27 | 42.2% | 37 | 57.8% | |
Age (10-years) | <= 50 (n = 13) | 5 | 38.5% | 8 | 61.5% | 0.634 |
51–60 (n = 20) | 8 | 40.0% | 12 | 60.0% | |
61–70 (n = 30) | 11 | 36.7% | 19 | 63.3% | |
71–80 (n = 36) | 19 | 52.8% | 17 | 47.2% | |
81+ (n = 13) | 7 | 53.8% | 6 | 46.2% | |
Of a total of 112 patients, who were initially selected for pre and post training laparoscopic surgery, nine of them (8.0%) were excluded due to conversion from laparoscopic to open surgery.
Table 2
Distribution of operation conversion between training group (A) and post-training group (B)
| Group | Total | |
Α | Β |
n | % | n | % | n | % | p |
Conversion | No | 46 | 92.0% | 57 | 91.9% | 103 | 92.0% | 0.99 |
Yes | 4 | 8.0% | 5 | 8.1% | 9 | 8.0% | (0.635) |
Patient’s diagnoses and operation types
The distribution of operation types in groups A and B are shown in Fig. 1. There is a higher number of sigmoidectomies in group B (n = 22) in comparison to group A (n = 12), while the opposite pattern was shown in ELAPE operations, n = 3 for group B vs n = 10 for group A (Fig. 1). A significant difference in the frequencies of operation types was found for group A and B patients (p = 0.045).
Number of lymph nodes, days of Hospitalization, duration of operation and clinical characteristics between pre and post training period
In Table 3 the distribution of operation margins and complications during operation in pre (A) and post (B) training group, are shown. Only 1 patient had positive margins, and this was recorded in A group. There is no significant difference in type of margin proportions between groups (p = 0.301). Operational complications were observed in 7 cases in total number of patients (6.8%). The distribution of complications were 4 cases in group A (8.0%) and 3 cases in group B (5.7%) which is not significantly different between groups (p = 0.637).
Table 3
Distribution of complications during operation and type of operation margins
| Group | |
Α | Β | |
n | n | n | % | p |
Margins | Free | 49 | 98.0% | 53 | 100.0% | 0.301 |
Positive | 1 | 2.0% | 0 | 0.0% | |
Complications | No | 46 | 92.0% | 50 | 94.3% | 0.637 |
Yes | 4 | 8.0% | 3 | 5.7% | |
For each of these 7 patients with complications, a laparotomy was performed after the initial laparoscopic colorectal operation. In addition, the patient of Group B with anastomotic leak after sigmoidectomy, died the postoperative period of the second surgery due to deterioration of the respiratory system. No other death reported, neither during the laparoscopic colorectal surgeries nor the immediate postoperative period.
Table 4
Description of complications between two groups
Group |
| Α | Β |
| Complications | |
Anastomotic leak | 2 | 1 |
Stenosis of anastomosis | 1 | 0 |
Ligature of ureter | 1 | 0 |
Lesion of urinary bladder | 0 | 1 |
Lesion of the iliac vein | 0 | 1 |
TOTAL NUMBER | 4 | 3 |
Table 5
Description of complications for each type of surgery
Complications | Type of Surgery |
| Right colectomy | Sigmoidectomy | Low anterior resection | ELAPE |
Anastomotic leak | - | 1 | 2 | - |
Stenosis of anastomosis | - | 1 | - | - |
Ligature of ureter | 1 | - | - | - |
Lesion of urinary bladder | - | 1 | - | - |
Lesion of the iliac vein | - | 1 | - | - |
TOTAL NUMBER | 1 | 4 | 2 | 0 |
Patients in both groups were operated for the same median number of lymph nodes. Median and quartile range of lymph nodes for group A were 20 (14–28), while for group B were 26 (16–34) showing no statistically significant differences (p = 0.145). Hospitalization days were not significantly different in both groups (p = 0.109) showing a median of 7 (5–8) for group A and 6 (5–7) for group B. Operation duration was less in post training group (group B) (median 4.0, 3.5-4.0) vs pre-training group (group A) (median 4.5, 3.5–5.5) (p = 0.006) (Table 6).
Table 6
Number of lymph nodes, days of hospitalization and operation duration between training (group A) and post-training group (group B)
| Group | |
A | B | |
Mean | SD | Quartiles | Mean | SD | Quartiles | p* |
| | | 1st | 2nd | 3rd | | | 1st | 2nd | 3rd | |
Operation duration (hours) | 4.5 | 1.2 | 3.5 | 4.5 | 5.5 | 4.0 | 1.4 | 3.5 | 4.0 | 4.0 | 0.006 |
Hospitalization (days) | 7.9 | 4.7 | 5.0 | 7.0 | 8.0 | 6.2 | 1.9 | 5.0 | 6.0 | 7.0 | 0.109 |
Lymph Nodes (number) | 22.3 | 12.2 | 14.0 | 19.5 | 28.0 | 26.8 | 15.1 | 16.0 | 26.0 | 34.0 | 0.145 |
* Mann-Whitney test |
Operation characteristics between training group (A) and post training group (B) per type of operation
When type of operation was considered during A vs B group comparison, although the median duration of operations were lower in group B than A, significance was present only in Low anterior resection 4.5 (4.0-4.5) for group B vs 5.5 (4.5–5.5) for group A (p = 0.036). A tendency for significance was found for sigmoidectomy (p = 0.059). Group B showed a median of 3.5 (3.5-4.0) vs 4.5 (3.5-5.0) for group A (Table 7).
Table 7
Difference in operation characteristics between training group (A) and post training group (B) per type of operation
| | Group | |
A | B |
Quartile | Quartile |
Operation | 1st | 2nd | 3rd | 1st | 2nd | 3rd | P |
Duration (hours) | Sigmoidectomy | 3.5 | 4.5 | 5.0 | 3.5 | 3.5 | 4.0 | 0.059 |
Right colectomy | 3.5 | 4.0 | 5.0 | 3.5 | 3.5 | 4.0 | 0.286 |
ELAPE | 4.5 | 6.0 | 6.0 | 4.3 | 5.0 | 5.8 | 0.937 |
Low anterior resection | 4.5 | 5.5 | 5.5 | 4.0 | 4.5 | 4.5 | 0.036 |
Hospitalization (days) | Sigmoidectomy | 6 | 6 | 8 | 5 | 5 | 7 | 0.557 |
Right colectomy | 5 | 7 | 8 | 5 | 6 | 7 | 0.697 |
ELAPE | 7 | 8 | 9 | 7 | 9 | 10 | 0.371 |
Low anterior resection | 6 | 7 | 8 | 6 | 6 | 7 | 0.713 |
Lymph nodes (number) | Sigmoidectomy | 14 | 17 | 27 | 12 | 23 | 33 | 0.901 |
Right colectomy | 18 | 22 | 28 | 20 | 28 | 36 | 0.240 |
ELAPE | 7 | 14 | 16 | 16 | 18 | 37 | 0.077 |
Low anterior resection | 15 | 25 | 29 | 20 | 28 | 34 | 0.713 |
Timeline of operation duration
An alternative approach was shown in Fig. 2. The timeline of operation duration in hours was presented vs consecutive patients’ number for each of the operation types. Independently on group (A or B), there is a significant decrease in operation time for sigmoidectomies (rs=-0.382, p = 0.026) as operation duration vs patients’ consecutive series showed. The same declining pattern was found for right colectomy operations (rs=-0.389, p = 0.013) and ELAPE (rs=-0.554, p = 0.050). A tendency for declining was found for low anterior resection (rs=-0.446, p = 0.083).