Objectives:An analysis of the risk factors for pharyngocutaneous fistula following surgery for hypopharyngeal cancer was performed in order to gain insight into the infectious agents involved and determine the distribution and antimicrobial susceptibility patterns of these pathogens.The findings shed light on the prudent application of prophylactic antibiotics and targeted treatment approaches for this troublesome complication.Methods:1.A retrospective study was conducted at our department of otolaryngology and the department of otolaryngology at a tertiary hospital in Kunming,in which patients diagnosed with malignant tumors were treated by an experienced chief physician who performed laryngeal and hypopharyngeal cancer resection surgery.Complete hospitalization medical records of patients were collected.Multiple related indicators that might affect postoperative pharyngocutaneous fistula development were analyzed,such as patient-specific factors(gender,age,preoperative body mass index,smoking history,alcohol consumption history)and tumor-related factors(tumor location,tumor T staging,pathological classification),and the experimental group was divided into"pharyngocutaneous fistula group"and"no pharyngocutaneous fistula group".The aforementioned indicators were imported into SPSS 25.0 software,and a chi-square test was used to perform statistical analysis on the data obtained in this experiment.If the chi-square test conditions were not met,Fisher’s exact probability test was used.Variables that were found to be associated with the incidence of pharyngocutaneous fistula after surgery for laryngeal or hypopharyngeal cancer were identified as independent variables,and the occurrence of pharyngocutaneous fistula was used as the dependent variable for binary logistic multiple regression analysis.After screening for independent risk factors associated with pharyngocutaneous fistula based on the confidence interval of the odds ratio,a forest plot was created using Med Calc 20.0 to visually display the independent risk factors associated with pharyngocutaneous fistula.P<0.05 was considered statistically significant.2.Patients with pharyngocutaneous fistula were sampled by sterile cotton swabs to collect secretions and/or pus from the fistula orifice.The specimens were placed into sterile tubes and timely transported to the microbiology laboratory of two hospitals.The isolation,culture,identification,and susceptibility testing of pathogens were performed by the fully automated culture system of the microbiology laboratory from the two hospitals.The pathogens isolated and the related drug susceptibility data were statistically analyzed.The composition proportion of the pathogens and the distribution of drug-resistant bacteria against commonly used antibiotics were calculated using percentages.Results:1.The overall incidence of pharyngocutaneous fistula after surgery for laryngeal and hypopharyngeal carcinoma was approximately 17.75%(41/231).Chi-square test(Fisher’s exact probability test was used when the chi-square test conditions were not met)showed no significant correlation between patient gender,age,and alcohol consumption history and the occurrence of pharyngocutaneous fistula after surgery for laryngeal and hypopharyngeal carcinoma(P>0.05).Preoperative BMI,smoking history,tumor location,tumor T stage,and pathological classification were statistically significant factors(P<0.05)that were included in the binary logistic regression analysis.The results indicate that preoperative BMI<18.5kg/m~2,no smoking history,and hypopharyngeal carcinoma are independent risk factors for pharyngocutaneous fistula after surgery for laryngeal and hypopharyngeal carcinoma(P<0.05).Based on the confidence intervals of the odds ratios for the independent risk factors,a forest plot was created using Med Calc 20.0,which revealed that patients with preoperative BMI<18.5kg/m~2 had a 3.299-fold greater risk of pharyngocutaneous fistula after surgery compared to those with preoperative BMI≥18.5kg/m~2.Patients with no smoking history had a 3.577-fold greater risk of pharyngocutaneous fistula after surgery compared to those with a smoking history.Patients with hypopharyngeal carcinoma had a 7.293-fold greater risk of pharyngocutaneous fistula after surgery compared to those with laryngeal carcinoma.Moreover,patients with tumors located in the hypopharynx have a significantly increased incidence of pharyngocutaneous fistula after surgery.2.In the univariate analysis by gender,the incidence of pharyngocutaneous fistula was 17.49%in male patients and 25.00%in female patients,with no significant difference between the two groups(P=0.940>0.05).Regarding age,the incidence of pharyngocutaneous fistula was 18.90%in patients<60 years old and 16.35%in patients≥60 years old,with no significant difference between the two groups(P=0.614>0.05).Among patients with a history of alcohol consumption,the incidence of pharyngocutaneous fistula was 16.20%,while among those without such history,it was20.22%,with no significant difference between the two groups(P=0.436>0.05).Among patients with a history of smoking,the incidence of pharyngocutaneous fistula was 14.95%,while that among patients without such history was 32.43%,showing a statistically significant difference(P=0.011<0.05).Finally,the incidence of pharyngocutaneous fistula was 14.21%in patients with laryngeal cancer and 55.00%in those with hypopharyngeal cancer,showing a statistically significant difference(P<0.001).3.In the co-culturing of secretions and/or pus from pharyngeal fistulas,a total of 18 genera of bacteria and 50 strains of pathogens were identified.Among them,10 genera(32 strains,64.00%)were gram-negative,7 genera(16 strains,32.00%)were gram-positive,and 1 genus(2 strains,4.00%)was fungi.Among the main gram-negative bacteria identified,Pseudomonas aeruginosa accounted for 9 strains(18.00%),followed by Klebsiella pneumoniae with 7 strains(14.00%)and Acinetobacter baumannii with 6 strains(12.00%).Among the main gram-positive bacteria identified,Streptococcus mitis accounted for 6 strains(12.00%),followed by Staphylococcus aureus with 4 strains(8.00%)and Streptococcus pneumoniae with 2 strains(4.00%).The fungi identified were both Candida albicans(2 strains,4.00%).4.The antibiotic resistance profiles of gram-positive and gram-negative bacteria were as follows:Gram-positive bacteria showed high resistance to erythromycin(80%),tetracycline(75%),amoxicillin-clavulanate(67%),cefuroxime(50%),and clindamycin(50%).Gram-negative bacteria exhibited high resistance to ampicillin(75%),cefotaxime(45%),ampicillin-sulbactam(38%),cefuroxime(38%),and amikacin(33%).Conclusions:1.There is a significant correlation between preoperative body mass index or nutritional status and postoperative pharyngocutaneous fistula following laryngopharyngectomy for hypopharyngeal or oropharyngeal cancer.2.Patients with hypopharyngeal cancer are more susceptible to pharyngocutaneous fistula after surgery compared to those with laryngeal cancer.Smoking does not increase the incidence of postoperative pharyngocutaneous fistula in patients with hypopharyngeal or laryngeal cancer.3.In patients with pharyngocutaneous fistula,gram-negative bacteria are the predominant pathogens,followed by gram-positive bacteria,and fungal infections may also accompany.4.Various Gram-positive bacteria are highly resistant to penicillins,second-generation cephalosporins,macrolides,tetracyclines,and lincosamides.With respect to Gram-negative bacilli,they exhibit high resistance to penicillins,first and second-generation cephalosporins,and ampicillin;while presenting strong resistance to third and fourth-generation cephalosporins,aminoglycosides,quinolones,and some carbapenems. |