Patients’ characteristics & Univariate analysis
Out of 491 patients who qualified for the study, 398 (81.05%) patients underwent total abdominal colectomy. Only 93 (18.94%) patients underwent partial colectomy. Approximately 84% of patient underwent colectomy for toxic colon and approximately 16% of patients underwent colectomy for perforation. The median [IQR] age of the patient who underwent partial colectomy was 66 [55-75], the male and female distribution was almost split equally with slight increase of male dominance, ~53% and about 77% of patients were Caucasians. There were significant differences found between the two groups, TAC and partial colectomy groups, regarding the presence of septic shock prior to surgery (67.8% versus 52.7%, P=0.03). TAC group presented with higher percentage of life threatening of ASA class (66.3% versus 59.1%, P=0.029) and found to have higher number of patients with history of steroid use (22.9% versus 12.9%, P=0.047). Significantly higher proportion of patients in TAC group mounted severe leukocytosis (≥20 × 109/L). Table 1.
Propensity matching analysis
The propensity matching created 93 pairs. There was significant improvement in patients’ characteristics after the matching. The pair matched analysis showed that all the differences between the two groups found in univariate analysis were balanced after the matching. Figure 1.
There were no differences between the groups, TAC versus partial colectomy, regarding median age 65[57-75] vs. 66 [66-75], race [Caucasians] 73.1% vs. 77.4%, gender [male] (49.5% vs. 52.7%), septic shock prior to surgery (55.9% vs. 52.7%) and ventilator dependent respiratory failure (37.6% vs. 29%) and comorbidities, all p values were >0.05. Table 2
There was no significant difference in mortality between the TAC and partial colectomy groups (30.1% vs. 30.15, P>0.99). The median [95% CI] hospital length of stay between the TAC and partial colectomy was (23 [19-31] vs. 21 [17-25], P=0.30). There was no significant difference found between the groups, TAC and partial colectomy, regarding the discharged disposition to home (43.1% vs. 33.8%) or transfer to rehab (21.55 vs. 12.3%, P=0.357). Table 3
There were no significance differences found between the two groups regarding surgical site infections, incidence of pneumonia, urinary tract infections, sepsis, septic shock, return to operating room, failure to wean from the ventilator and readmission rates. Table 4
Discussion.
Our study showed that the majority, ~81.0% of FCDC patients underwent total abdominal colectomy while only ~19% of patients had partial colectomy. The all-cause 30-days mortality in the matched group was 30.1%. Partial colectomy did not show any difference in overall mortality or post-operative complications and discharge disposition to home.
Prior studies showed that early colectomy had a better survival probability than no colectomy (4, 14). Total abdominal colectomy has been the practice pattern for many decades in fulminant cases of FCDC (5). In 2015, World Society of Emergency Surgery (WSES) recommendation was to perform early TAC in the management of FCDC (15). The updated WSES guidelines in 2019 kept the TAC as a primary choice of surgical intervention (16).
Very few prior studies have examined the comparison of mortality outcome of TAC with partial colectomy. A study looked at the surgical mortality of the FCDC found that patients underwent partial colectomy had the worse outcome than the TAC (17). The major limitation of the study was a very small sample size. The total number of patients included in the study was 14 and the major reasons for the high mortality in partial colectomy was not very clear. Byrn and colleagues examined 73 patients with FCDC who underwent colectomy (18). The majority of colectomies (86%) were subtotal colectomy, only 4 patient had right hemicolectomy and 5 had left hemicolectomy and one patient had total colectomy. One patient who had left hemicolectomy was converted to total colectomy. No significant difference was found in overall mortality whether the patient underwent partial colectomy or subtotal colectomy (10% vs 38%, respectively; P > .05). A recent NIQIP database study included all patients with FCDC who underwent colectomies from 2007 through 2015 (8). The study consisted of 733 patients and found slightly higher mortality rate in partial colectomy group when compared to TAC (37.1% vs 34.7%) in univariate analysis. However, multiple logistic regression analysis did not show any significant difference in mortality of partial colectomy group when compared with TAC, the odds ratio [OR] was 1.21, 95% CI 0.76 to 1.96.
Contrary to above studies, our study included relatively recent NSQIP data set and used propensity-matched analysis, which is the better modality for observational study (10). Our results showed 81% of patients underwent TAC as recommended by the WSES (16). Approximately 19% of patients underwent partial colectomy. The reasons for lower compliance with WSES were not available. There is a possibility that, in certain cases, the point of care surgeon made the decision to perform partial colectomy was based on findings observed during the operation. Patients who underwent partial colectomy showed no difference in 30 days mortality (30.1% vs. 30.1%) when compared with TAC. Our mortality was little lower than the published report (8). The reason may be that we used the most recent dataset that may have reflected the better selection of patients to critical care management and aggressive treatment of the FCDC (19). The other reason for lower mortality in our study could be the inclusion of all comorbidities in our propensity-matching model that can influence the post-operative mortality (20). Our study did not find any significant difference in median hospital length of stay and 30-day post-operative complications regardless of the type of surgery was performed (TAC vs. partial colectomy). Our study added one more outcome to look at the discharged disposition to home and found no significant difference between the TAC vs. partial colectomy. Table 3.
Limitation.
The study was done from the NIQIP database; however, the database lacks the detailed information of the some of the patients’ characteristics. The timing of the contraction of the clostridium difficile colitis, progress to FCDC and the timing of the colectomy from the time of identification of the FCDC. We used the most recommended analysis method of observational study, the propensity score matching. However, that method does not take into account any unobserved or unmeasured variables that may have influenced the results.