Colorectal
surgeries are performed due to colon cancer, rectal cancer, complicated
diverticular disease, colonic perforation, colonic volvulus, familial
adenomatous polyposis, appendicular tumour, ulcerative colitis and colostomy
owner. Colorectal surgeries include right hemicolectomy, transverse colectomy,
left hemicolectomy, sigmoid colectomy, subtotal/total colectomy, anterior
resection, colocolic anastomosis, and Hartman reversal [1]. Complications after
intestinal resection and anastomosis include bleeding, stricture, and
anastomotic leakage [2]. Anastomotic leakage is defined as the presence of pus
or enteric contents within the drains, presence of abdominal or pelvic
collections in the area of anastomosis on postoperative imaging, leakage of
contrast through the anastomosis during an enema or evident anastomotic
dehiscence at reoperation for postoperative peritonitis [3]. It is one of the
most dreaded complications following colorectal surgery, with rates of 3-27%
depending on specific risk factors [4]. It typically becomes clinically
apparent between the 5th and 8th postoperative days. If diagnosed late,
anastomotic leakage (AL) can progress to overwhelming sepsis, multiple organ
dysfunction, and death [2,4,5]. Delayed diagnosis and subsequent delay in
antibiotic administration from the onset of septic shock have been associated
with a decrease in survival of 7.6 percent per hour. [6] Long-term consequences
of significant AL may include increased risk of colorectal cancer recurrence,
reduced quality of life, and decreased long-term survival. Thus, an early
prediction of AL before clinical symptoms become apparent is of utmost
importance [7-9]. Fever, pain, tachycardia, peritoneal purulent or faecal
drain, and dynamic ileus have commonly been suggested as clinical signs of AL.
The mean time to clinical diagnosis was 6-12 days after surgery [10-14].
Several biochemical and hematological markers have been proposed to be
associated with AL, such as leukocyte count, C-reactive protein (CRP), serum
procalcitonin (PCT) levels, hypoalbuminemia, neutrophil-lymphocyte ratio (NLR),
platelet lymphocyte ratio (PLR), and derived neutrophil-lymphocyte ratio
(dNLR). Patients with anastomotic leakage (AL) had significantly greater mean
WBC and neutrophil values but lower mean lymphocyte values on the 4th POD
[15-19]. In addition, the mean NLR, dNLR, and PLR values were consistently
greater in patients who developed AL. Among the blood cell indexes of
inflammation evaluated, NLR on the 4th postoperative day showed the best ability
to predict AL with a cut-off value of 7.1. Nevertheless, its potential
usefulness in daily practice needs to be further evaluated in prospective
studies. CRP is a nonspecific acute-phase protein [19]. In some retrospective
studies, it was observed that from the second postoperative day onwards, mean
serum CRP was found to be significantly higher (>140 mg/L) in the group who
developed AL, and this marker remained elevated until the diagnosis of the
complication. Again, its potential usefulness in daily practice needs to be
further evaluated in prospective studies [16,20]. Preoperative hypoalbuminemia,
a well-known indicator for malnutrition, is one of the most prevalent risk
factors associated with postoperative complications in colorectal surgery, including
anastomotic leakage. In a retrospective study, it was found that postoperative
serum albumin levels in AL were significantly lower than those in
nonanastomotic leakage (NAL) on POD 0, POD 1, POD 3, and POD 7 [21-23]. As this
was a retrospective study and there is no other study regarding this predictor,
it demands a prospective study before clinical implication [24]. Compared with
the other biochemical and hematological markers, procalcitonin was found to be
the most reliable biomarker for the early diagnosis of anastomotic leak.
However, stressing the issue of increased costs, as determination of serum PCT
concentration is 4-20-fold more expensive than the estimation of CRP level, we
do not include it in our study [25]. Therefore, in the present study, we
investigated the role of postoperative leukocyte count, NLR, PLR, CRP, and
serum albumin as early predictive markers of anastomotic leakage following
colorectal surgery (CRS).
Methods
This
prospective analytical type of study was conducted at the Department of
Surgery, Dhaka Medical College & Hospital, and Dhaka for a period of one
year from November 2020 to October 2021. A total of 70 patients who underwent
colorectal surgery were included by convenient, consecutive sampling as study
patients according to inclusion and exclusion criteria. Each patient was
subjected to detail clinical evaluation along with history taking. All patients
underwent relevant investigations when needed. White blood cell (WBC) count,
Neutrophil lymphocyte ratio (NLR), Platelet lymphocyte ratio (PLR), C-reactive
protein (CRP) and Serum albumin level were measured pre-operatively and at 1st
and 4th post-operative day (POD). A standard guideline was followed during
post-operative management. A semi-structured questionnaire and collected data
were analysed by using the statistical software SPSS 27.
Results
Male
patients were significantly more likely to have AL than female patients (63.6%
vs 36.4%, p=0.040), and the mean age of the patients was significantly higher
among AL than non-AL patients (68.3±1.79 vs 62.8±6.01, p=0.004). Patients with
AL had a significantly lower mean BMI value (16.6±0.90 vs 21.2±3.51, p= 0.002)
and more than 10% weight loss in the preceding 6 months (81.8 vs 27.1, p=0.001)
(Table 1). The majority of the patients had a normal BMI (62.9%), followed by
21.4% who were underweight and 11.4% and 4.3% who were overweight and obese,
respectively. Among the AL patients,
the majority had a fitness grade of III (54.5%) compared to non-AL patients
(18.6%). Moreover, among AL and non-AL patients, 36.4% and 57.6% had a fitness
grade of II, respectively.

Figure 1: Incidence of anastomotic leakage
among the study patients (n=70). Among the 70 patients, 11 (15.7%) patients
were reported to have anastomotic leakage.

Figure
2: Distribution of
nutritional status according to BMI among the patients (n=70).

Figure
3: Distribution of
ASA fitness grade among the AL and non-AL patients (n=70).

Figure 4:
ROC curves of WBC, NLR, PLR and CRP in predicting anastomotic leakage
(n=70).
There
was a significantly higher fitness grade among AL than non-AL patients
(p=0.037). Among the patients, the surgery type played a significant role in
the increased risk of AL (p=0.007), and transverse colectomy and total
colectomy increased the risk of AL (27.3%) compared with other surgery types.
As shown in Table 4.3, no significant differences were found preoperatively
between patients with and without anastomotic leakage in the median values of
WBCs count, NLR and PLR. On the first postoperative day, the PLR was
significantly higher (AL-213 vs non-AL-190, p<0.001). However, the greatest
significant differences were registered on the 4th postoperative day. On that
day, patients with AL had significantly greater WBC (12 vs 6.36, p=0.014) and
NLR (9.34 vs 5.6, p < 0.0001) values, PLR (213 vs 190, p-0.031). AL-with
anastomotic leakage, non-AL-without anastomotic leakage, NLR-neutrophil to
lymphocyte ratio, PLR- platelet to lymphocyte ratio, WBC-white blood cell
count. As shown in Table 4, no significant differences were found
preoperatively between patients with and without anastomotic leakage in the
median values of C-reactive protein and serum albumin (p>0.05). On the first
postoperative day, the serum albumin level was significantly lower (AL-2.9 vs
non-AL-3.4, p<0.001). However, the greatest significant differences were
registered on the 4th postoperative day. On that day, patients with AL had
significantly greater CRP (17.6 vs 8.48, p<0.001) and significantly lower
serum albumin level (AL-2.8 vs non-AL-3.1, p=0.005). AL-with anastomotic
leakage, non-AL-without anastomotic leakage, CRP-C-reactive protein While
assessing the reports of 1st and 4th postoperative day among the AL patients it
was observed that the WBC,PLR,NLR was significantly higher and serum albumin
level was significantly lower at the 4th postoperative day(p<0.05). There
was no significant rise in the CRP level on the 4th postoperative day compared
to the 1st postoperative day. POD-Postoperative day, AL with anastomotic leakage,
NLR-neutrophil to lymphocyte ratio, PLR platelet to lymphocyte ratio,
CRP-C-reactive protein, WBC-white blood cell count. A ROC curve analysis was
performed for the indexes that showed statistically significant differences
between the two groups of patients on the 4th postoperative day (Table 6, Figure
4). NLR at a cut-off point of 8.7 showed the best AUC (0.827, 95% CI 0.73–0.93)
with a sensitivity and specificity of 63.3% and 74.6%, respectively, followed
by the WBC (0.814, 95% CI 0.68–0.95) at a cut-off point of 9.1 and CRP (0.802,
95% CI 0.63–0.97) .The AUC of PLR (0.75, 95% CI 0.60-0.90) and serum albumin
(0.775, 95% CI 0.63–0.97) showed a relatively poor result compared to WBC and
NLR and CRP.
Table 1:
Distribution of demographic and clinical features of the patients with
and without AL (n=70).
|
Variables
|
All patient
(n=70)
n(%)
|
AL (n=11)
n(%)
|
Non-AL (n=59)
n(%)
|
p value*
|
|
Gender
|
|
Male
|
59(84.3)
|
7(63.6)
|
52(88.1)
|
0.040
|
|
Female
|
11(15.7)
|
4(36.4)
|
7(11.9)
|
|
|
Age
|
|
Mean±SD
|
63.6±7.09
|
68.3±1.79
|
62.8±6.01
|
0.004
|
|
BMI(kg/m2)
|
|
Mean±SD
|
20.8±3.69
|
16.6±0.90
|
21.2±3.51
|
0.002
|
|
Weight loss in preceding 6 months
(>10%)
|
|
Yes
|
25(35.7)
|
9(81.8)
|
16(27.1)
|
0.001
|
|
No
|
45(64.3)
|
2(18.2)
|
43(72.9)
|
|
|
Indication of surgery
|
|
Malignant pathology
|
64(91.4)
|
9(81.8)
|
55(93.2)
|
|
|
Benign pathology
|
6(8.6)
|
2(18.2)
|
4(6.8)
|
|
|
Diabetes mellitus
|
|
Yes
|
9(12.9)
|
2(18.2)
|
7(11.9)
|
0.566
|
|
No
|
61(87.1)
|
9(81.8)
|
52(88.1)
|
|
Table 2: Distribution of type
of surgery among the patients with and without AL (n=70).
|
Variables
|
AL (n=11)
n(%)
|
Non-AL (n=59)
n(%)
|
p value*
|
|
Surgery type
|
|
|
|
|
Right hemicolectomy
|
1(9.1)
|
22(37.3)
|
0.007
|
|
Left
hemicolectomy
|
2(18.2)
|
18(30.5)
|
|
Transverse
colectomy
|
3(27.3)
|
4(6.8)
|
|
Anterior
resection
|
-
|
-
|
|
Subtotal/Total
colectomy
|
3(27.3)
|
6(10.2)
|
|
Others
|
2(18.2)
|
9(15.3)
|
Table 3: Comparisons of the median values of the
hematological markars studied preoperatively and on the 1st and 4th
postoperative days in patients with and without anastomotic leakage (n=70).
|
Hematological markars
|
Patients
(n=70)
|
Preoperative day
Median(IQR)
|
1st postoperative day
Median(IQR)
|
4th postoperative day
Median(IQR)
|
|
WBC (/109L)
|
Non-AL
|
6.37(5.78-6.70)
|
9.87(9.0-10.4)
|
6.36(6.0-7.34)
|
|
|
AL
|
6.40(5.78-6.70)
|
10.4(9.8-11.0)
|
12.0(10.0-14.0)
|
|
|
p value*
|
0.879
|
0.308
|
0.014
|
|
NLR
|
Non-AL
|
2.2(2.0-2.8)
|
8(7.0-9.0)
|
5.6(4.3-6.3)
|
|
|
AL
|
2.8(1.0-3.0)
|
9.0(8.0-9.0)
|
9.34(8.4-9.8)
|
|
|
p value*
|
0.727
|
0.195
|
<0.001
|
|
PLR
|
Non-AL
|
176(159-183)
|
200(190-220)
|
190(180-200)
|
|
|
AL
|
178(177-200)
|
210(200-260)
|
213(210-240)
|
|
|
p value*
|
0.509
|
<0.001
|
0.031
|
|
P value obtained by Mann–Whitney U test
|
Table
4: Comparisons of
the median values of the biochemical markers studied preoperatively and on the
1st and 4th postoperative days in patients with and without anastomotic leakage
(n=70).
|
Biochemical markers
|
Patients
(n=70)
|
Preoperative day
Median(IQR)
|
1st postoperative day
Median (IQR)
|
4th postoperative day
Median (IQR)
|
|
CRP (mg/l)
|
Non-AL
|
0.60(0.32-0.93)
|
9.0(7.8-10)
|
8.48(7.6-8.9)
|
|
|
AL
|
0.88(0.40-1.60)
|
13.6(12.3-15.4)
|
17.6(15.8-19)
|
|
|
p value*
|
0.241
|
0.587
|
<0.001
|
|
Serum albumin (g/dl)
|
Non-AL
|
3.6(3.4-3.9)
|
3.4(3.4-3.5)
|
3.1(2.9-3.3)
|
|
|
AL
|
3.8(3.5-3.9)
|
2.9(2.5-3.2)
|
2.8(2.3-2.9)
|
|
|
p value*
|
0.354
|
<0.001
|
0.005
|
|
*p
value obtained by Mann–Whitney U test
|
Table 5: Comparisons of the median values of
the indexes studied on the 1st and 4th postoperative days in patients with AL
(n=11).
|
Hematological and biochemical markers
|
1st POD
Median(IQR)
|
4th POD
Median(IQR)
|
p value*
|
|
CRP(mg/l)
|
13.6(12.3-15.4)
|
17.6(15.8-19)
|
0.893
|
|
WBC(/109L)
|
10.4(9.8-11.0)
|
12.0(10.0-14.0)
|
<0.001
|
|
NLR
|
9.0(8.0-9.0)
|
9.34(8.4-9.8)
|
<0.001
|
|
PLR
|
210(200-260)
|
213(210-240)
|
<0.001
|
|
Serum
albumin(g/dL)
|
2.9(2.5-3.2)
|
2.8(2.3-2.9)
|
<0.001
|
|
*p
value obtained by Wilcoxon signed-rank test
|
Table 6: Receiver’s operating curve (ROC) of
the indexes under evaluation as predictive markers of anastomotic leakage.
|
Marker
|
AUC
|
95%CI
|
p value
|
Cutoff
|
Sensitivity
|
Specificity
|
|
WBC
|
0.814
|
(0.68-0.95)
|
0.001
|
? 9.11
|
72.7
|
78
|
|
NLR
|
0.827
|
(0.73-0.93)
|
0.001
|
? 8.7
|
63.3
|
74.6
|
|
PLR
|
0.754
|
(0.60-0.90)
|
0.008
|
? 205
|
72.7
|
71.2
|
|
CRP
|
0.802
|
(0.63-0.97)
|
0.002
|
? 9.98
|
81.8
|
76.3
|
|
Serum albumin
|
0.775
|
(0.66-0.89)
|
0.060
|
? 3.03
|
72.7
|
66.1
|