The Clinical Study On The Use Of Wound Drainage Tube After Posterior Lumbar Fusion With Instrumentation And New Surgical Strategies For Early Deep Surgical Site Infection

Part 1 Risk factors for increased surgical drain output after posterior lumbar fusion with instrumentationBackground:Posterior lumbar fusion with instrumentation is an effective method for the treatment of lumbar degenerative diseases.The drainage tube was routinely placed in the incision before closing the incision.In theory,the use of drainage tube is beneficial to discharge postoperative blood accumulation in the surgical incision,reduce postoperative bleeding and incision tension,and thus reduce the risk of surgical site infection(SSI)and neurological dysfunction due to hematoma accumulation.However,many patients treated with posterior lumbar fusion with instrumentation have more postoperative drain output which can easily lead to increased blood loss,anemia,hypoproteinemia,increased need for blood transfusion,and even increased risk of postoperative SSI.Therefore,it is of great importance to identify the risk factors for increased surgical drain output after posterior lumbar fusion with instrumentation and then take effective measures to intervene in order to reduce postoperative drain output and the risk of related complications.Objective:To investigate the risk factors for increased surgical drain output after posterior lumbar fusion with instrumentation,so as to provide a reference for clinicians to take active and effective intervention measures to prevent it.Methods:368 patients who underwent posterior lumbar fusion with instrumentation from June 2018 to January 2020 were enrolled in this study.The drainage tubes were routinely placed in all patients after posterior lumbar fusion with instrumentation.They were divided into the increased surgical drain output group and no increased surgical drain output group according to the boundary of the median drain output.Age,gender,body mass index(BMI),smoking history,medical history(diabetes mellitus,hypertension,coronary heart disease,and chronic obstructive pulmonary disease),preoperative American Society of Anesthesiologists(ASA)grade,preoperative laboratory data(red blood cell,hematocrit,hemoglobin,platelet count,prothrombin time,activated partial thromboplastin time,and international normalized ratio),surgical duration,intraoperative blood loss,intraoperative endplate injury,number of fused levels,administration of tranexamic acid(TXA),and postoperative drainage tube duration were compared between two groups.The risk factors for increased surgical drain output were identified by univariate and multivariate logistic regression analysis.Pearson or Spearman correlation analysis was used to identify the relationship between parameters.Results:The drain output for this cohort ranged 60 to 1490 mL,with a median of 480 mL.187 patients had increased surgical drain output(drain output≥ 50th percentile or 480 mL).Univariate analysis showed that there were no significant differences in gender,BMI,medical history,ASA classification,and preoperative laboratory data between the two groups(P>0.05).Age,smoking history,number of fused levels,intraoperative blood loss,intraoperative endplate injury,administration of tranexamic acid(TXA),surgical duration,and postoperative drainage tube duration were significantly associated with increased surgical drain output(P<0.05).Multiple logistic regression analysis revealed that older age(OR=1.042,P=0.001),smoking(OR=2.098,P=0.005),more fused levels(OR=3.476,P<0.001),intraoperative endplate injury(OR=2.096,P=0.017),and long duration of postoperative drainage tube(OR=2.105,P=0.003)were the independent risk factors,while administration of TXA(OR=0.540,P=0.012)was a protective factor for increased surgical drain output.The correlation analyses revealed that the degree of endplate injury was positively correlated with postoperative drain output(r=0.578,P<0.001),and the number of fused levels was positively correlated with intraoperative blood loss(r=0.601,P<0.001)and surgical duration(r=0.675,P<0.001).Conclusions:This study showed that older age,smoking,more fused levels,intraoperative endplate injury,and long duration of postoperative drainage tube were the independent risk factors,while administration of TXA was a protective factor for increased surgical drain output after posterior lumbar fusion with instrumentation.The degree of endplate injury was positively correlated with postoperative drain output,and the number of fused levels was positively correlated with intraoperative blood loss and surgical duration.Part 2 Comparison of two different criteria for postoperative drainage tube removal after posterior lumbar fusion with instrumentationBackground:The drainage tubes are widely used in posterior lumbar fusion with instrumentation in clinical practice,but it is still controversial when to remove drainage tubes after surgery.Although many scholars have reported that time driven or output driven is used as different indications of drainage tube removal after posterior lumbar fusion with instrumentation,no study has directly compared the efficacy differences of the two different criteria for postoperative drainage tube removal.There is no unified conclusion on which criterion for postoperative drainage tube removal is better.Objective:To compare the outcomes of two different criteria(time driven and output driven)for postoperative drainage tube removal after posterior lumbar fusion with instrumentation and identify which one is better.Methods:743 patients who underwent posterior lumbar fusion with instrumentation involving one or two motion segments from January 2017 to January 2019 were enrolled in this study.Based on the different criteria for postoperative drainage tube removal,the patients were divided into two groups.The drainage tubes were discontinued by time driven(postoperative day 2)in group A and output driven(<50 ml per day)in group B.There were 315 patients in group A and 428 patients in group B.Demographic characteristics were recorded including age,gender,body mass index(BMI),medical history(hypertension,diabetes mellitus,coronary heart disease,chronic obstructive pulmonary disease).Perioperative parameters were collected including surgical duration,number of fusion levels,intraoperative blood loss,postoperative drain output,total blood loss,number of intraoperative autologous or allogeneic blood transfusion,number of postoperative blood transfusion,postoperative timing of ambulation,postoperative duration of hospital stay,the incidence of early deep surgical site infection(SSI)or symptomatic spinal epidural hematoma.Clinical efficacy was evaluated using the visual analogue scale(VAS)for back and leg pain and the Oswestry disability index(ODI).Results:There were no significant differences in demographic characteristics including age,gender,BMI,and medical history in both groups(P>0.05).The postoperative drain output,total blood loss,postoperative timing of ambulation,and postoperative duration of hospital stay in group A were lower than those in group B(P<0.05).There were no statistical significant differences in surgical duration,number of fused levels,intraoperative blood loss,the number of patients requiring intraoperative blood transfusion,and the incidence of early deep SSI or symptomatic spinal epidural hematoma between the two groups(P>0.05).There was a higher proportion of patients requiring postoperative blood transfusion in group B,but not to a level of statistical significance(P=0.054).The mean value of drain output in group A on postoperative day 0 and 1 were 275.8±130.8 ml and 115.7±62.9 ml while the count in group B were 287.3±138.2 ml and 121.4±71.6 ml,respectively.The drain output on postoperative day 0 and 1 was comparable between the two groups(P>0.05).The ODI and VAS scores for back and leg pain improved from the preoperative assessment to postoperative 3 or 12 months in each group(P<0.05).There were no statistical differences in the ODI and VAS scores for back and leg pain at the same time point between the two groups(P>0.05).Conclusions:This study reveals that there are more benefits of postoperative drainage tube removal by time driven than that by output driven for patients undergoing posterior one-level or two-level lumbar fusion with instrumentation,including less postoperative drain output,less total blood loss,earlier postoperative timing of ambulation,and less postoperative duration of hospital stay without increasing the incidence of postoperative complications.Part 3 Risk factors and preventive strategies for early deep surgical site infection after posterior lumbar fusion with instrumentationBackground:Early deep surgical site infection(SSI)is one of the serious complications after posterior lumbar fusion with instrumentation,which can lead to a series of adverse consequences such as spinal instability,pseudojoint formation,nerve injury,fusion failure,and multiple surgeries.Therefore,it is important to identify the risk factors for early deep SSI and actively prevent it after posterior lumbar fusion with instrumentation.Previous studies have reported that there are many risk factors for SSI after spinal surgery,but different conclusions are drawn from different studies due to different risk factors included in the studies,and differences in sample size and evaluation criteria.Among them,the use of drainage tube is closely related to the occurrence of postoperative SSI,and the effect of postoperative drainage tube duration on postoperative SSI is controversial.Objective:To investigate the risk factors for early deep SSI after posterior lumbar fusion with instrumentation,further identify the relationship between postoperative drainage tube duration and early deep SSI,and summarize the preventive measures,so as to provide a reference for reducing the incidence of postoperative SSI.Methods:5016 patients who underwent posterior lumbar fusion with instrumentation for degenerative lumbar diseases from January 2013 to May 2020 were retrospectively analyzed.48 patients with early postoperative deep SSI were included in the infection group,and 192 patients were randomly selected from patients without postoperative SSI at a ratio of 1:4 and included in the control group.Age,gender,main diagnosis,body mass index(BMI),smoking history,medical history(diabetes mellitus,hypertension,coronary heart disease,and chronic obstructive pulmonary disease),preoperative anemia,hypoalbuminemia(albumin<35g/L),preoperative American Society of Anesthesiologists(ASA)grade,preoperative steroid hormone use,number of fused levels,surgical duration,perioperative blood loss,revision surgery,cerebrospinal fluid leakage,postoperative drainage tube duration,and allograft blood infusion were compared between two groups.The risk factors for early deep SSI were identified by univariate and multivariate logistic regression analysis.Results:Early deep SSI occurred in 48 of 5016 patients who underwent posterior lumbar fusion with instrumentation.The incidence of early deep SSI was 0.96%(48/5016),including 29 males and 19 females,aged 61.3±11.8 years(32-85 years).Univariate analysis showed that there were no significant differences in age,gender,main diagnosis,smoking history,hypertension,coronary heart disease,chronic obstructive pulmonary disease,preoperative anemia,preoperative ASA grade,preoperative steroid hormone use,number of fused levels,revision surgery,cerebrospinal fluid leakage,and allograft blood infusion between the two groups(P>0.05).Obesity(BMI≥28kg/m2),diabetes mellitus,preoperative hypoalbuminemia(albumin<35g/L),surgical duration,perioperative blood loss,and postoperative drainage tube duration were significantly associated with early deep SSI(P<0.05).Multiple logistic regression analysis revealed that obesity(OR=2.545,P=0.028),diabetes mellitus(OR=3.207,P=0.011),preoperative hypoalbuminemia(OR=9.745,P<0.001),and long duration of postoperative drainage tube(OR=3.224,P=0.005)were the independent risk factors for early deep SSI after posterior lumbar fusion with instrumentation.Conclusions:This study showed that obesity,diabetes mellitus,preoperative hypoalbuminemia,and long duration of postoperative drainage tube were the independent risk factors for early deep SSI after posterior lumbar fusion with instrumentation.For a series of risk factors of postoperative SSI,it is of great significance to develop perfect preventive measures at different stages for fundamentally reducing the occurrence of postoperative SSI.Part 4 A new surgical strategy for early deep surgical site infection after posterior lumbar fusion with instrumentationBackground:For early deep surgical site infection(SSI)after posterior lumbar fusion with instrumentation,timely and effective treatment is the key to a good prognosis.At present,there are various surgical treatment methods for early deep SSI after posterior lumbar fusion with instrumentation,but all of them have certain defects.It has become an urgent clinical problem about how to improve the surgical treatment technology,so as to better treat the early deep SSI after posterior lumbar fusion with instrumentation.Objective:To introduce a novel strategy of using incisional vacuum sealing drainage(VSD)following one-stage incision suture combined with closed suction irrigation system for treating early deep SSI after posterior lumbar fusion with instrumentation and to compare it with traditional closed suction irrigation system,which provides a new idea for the patients with early postoperative deep SSI to obtain more satisfactory clinical efficacy.Methods:5016 patients who underwent posterior lumbar fusion with instrumentation for degenerative lumbar diseases from January 2013 to May 2020 were retrospectively analyzed.A total of 48 patients developed early deep SSI,46 of whom were treated by meticulous debridement followed by either traditional closed suction irrigation system or incisional VSD following one-stage incision suture combined with closed suction irrigation system,including 24 patients in traditional closed suction irrigation system group(group A)and 22 patients in incisional VSD following one-stage incision suture combined with closed suction irrigation system group(group B).Demographic characteristics were recorded including age,gender,body mass index(BMI),follow-up period,symptoms of infection(fever,local pain or tenderness,local swelling,wound discharge,and wound dehiscence),and inflammatory marks(C-reactive protein,erythrocyte sedimentation rate,and procalcitonin).The treatment features were collected including interval time from the initial operation to debridement,the number of VAC foam dressing or ordinary dressing change before tubes removal,number of debridement,irrigation duration,intravenous antibiotic duration,oral antibiotic duration,hospital stay,total cost of SSI treatment,and implant retention.The bacterial cultures of all patients were collected.During the follow-up period,all patients were observed whether recurrent infections or other complications occurred.Results:A total of 48 patients(48/5016,0.96%)developed early deep SSI.There were no significant differences in age,gender,BMI,follow-up period,symptoms of infection,inflammatory marks,interval time from the initial operation to debridement,total cost of SSI treatment,and implant retention in both groups(P>0.05).The number of ordinary dressing change in group A was significantly more the number of VSD foam dressing change in group B(P<0.05).The number of debridement,antibiotic duration,and hospital stay in group A were significantly more those in group B(P<0.05).The irrigation duration in group A was significantly shorter than that in group B(P<0.05).Bacterial cultures were positive in 65.2%(30/46)of all patients,including 3 polymicrobial infections and 27 monomicrobial infections.A total of 16 patients had positive cultures in group A,including 14 monomicrobial infections and 2 polymicrobial infections,and 14 patients had positive cultures in group B,including 13 monomicrobial infections and 1 polymicrobial infection.The most common gram-positive pathogen was Staphylococcus aureus,including 6 cases in group A and 6 cases in group B,and the most common gram-negative pathogen was Escherichia coli,including 4 cases in group A and 5 cases in group B.One patient with severe infection accompanied by sinus tract formation in group A was treated with sinus tract resection and instrumentation removal.All other patients retained implant.All patients were eventually cured of the infections with satisfactory clinical outcomes.There were no recurrent infections during the follow-up period.Conclusions:Traditional closed suction irrigation system and incisional VSD following one-stage incision suture combined with closed suction irrigation system are two effective methods for the treatment of early deep SSI after posterior lumbar fusion with instrumentation.However,compared with traditional closed suction irrigation system,incisional VSD following one-stage incision suture combined with closed suction irrigation system has the advantages of less dressing changes,less debridements,longer irrigation duration,shorter duration of antibiotic use,and shorter hospital stay.The novel surgical strategy combines the advantages of traditional closed suction irrigation system and VSD and makes up for their shortcomings.It can prevent the leakage of flushing fluid or drainage fluid and avoid secondary incision suture with satisfactory clinical efficacy.