Mechanism of isoflurane­mediated breast cancer growth in vivo.

Use of volatile anesthetics is associated with worse outcome following tumor resection surgery compared with the use of intravenous anesthetics. However, the underlying mechanism has not been clearly delineated yet in vivo. The EO771 cell-based congenic breast cancer model was used in the present study. Isoflurane directly binds to and inhibits two adhesion molecules, leukocyte function-associated antigen-1 (LFA-1) and macrophage-1 antigen (Mac-1). Similarly, exposure to sevoflurane, another volatile anesthetic and LFA-1 inhibitor, is associated with an increase in breast cancer size compared with non-exposure. Thus, the present study first examined the role of LFA-1 and Mac-1 in the EO771 breast cancer model. Both LFA-1 deficiency and inhibition enhanced tumor growth, which was supported by cytokine and eicosanoid data profiles. By contrast, Mac-1 deficiency did not affect tumor growth. The exposure to isoflurane and sevoflurane was associated with an increase in breast cancer size compared with non-exposure. These data suggested that isoflurane enhanced tumor growth by interacting with LFA-1. Isoflurane exposure did not affect tumor growth in LFA-1-deficient mice. In summary, the present data showed that LFA-1 deficiency facilitated breast cancer growth, and isoflurane, an LFA-1 inhibitor, also increased breast cancer growth.

Cystic Fibrosis Mice Are Highly Susceptible to Repeated Acute Pseudomonas aeruginosa Pneumonia after Intranasal Inoculation.

Cystic fibrosis (CF) is a genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) that controls chloride current. A number of different CFTR transgenic mouse lines have been developed and subjected to both acute and chronic infection models. However, prior studies showed no substantial differences in bacterial clearance between CF and non-CF mice after single inoculations. Here, using F508del transgenic CF mice, we examined the role of repeated acute Pseudomonas aeruginosa (PA) infection, with the second inoculation 7 days after the first. We found that CF mice were more susceptible to PA infection than non-CF mice following the second inoculation, with non-CF mice showing better neutrophil recruitment and effector functions. We further investigated the characteristics of lung immune cells using single-cell RNA sequencing, finding that non-CF lung neutrophils had more prominent upregulation of adhesion molecules including intercellular adhesion molecule-1 (ICAM-1) compared to CF lung neutrophils. Although people with CF are often colonized with bacteria and have high numbers of neutrophils in the airways during chronic infection, these data suggest that CF neutrophils have deficient effector functions in the setting of repeated acute infection.

Perioperative Factors and Radiographic Severity Scores for Predicting the Duration of Mechanical Ventilation After Arterial Switch Surgery.

OBJECTIVES: Cardiac surgery on cardiopulmonary bypass (CPB) during the neonatal period can cause perioperative organ injuries. The primary aim of this study was to determine the incidence and risk factors associated with postoperative mechanical ventilation duration and acute lung injury after the arterial switch operation (ASO). The secondary aim was to examine the utility of the Brixia score for characterizing postoperative acute lung injury (ALI). DESIGN: A retrospective study. SETTING: A single-center university hospital. PARTICIPANTS: A total of 93 neonates with transposition of great arteries with intact ventricular septum (dTGA IVS) underwent ASO. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: From January 2015 to December 2022, 93 neonates with dTGA IVS were included in the study. The cohort had a median age of 4.0 (3.0-5.0) days and a mean weight of 3.3 ± 0.5 kg. About 63% of patients had ≥48 hours of postoperative mechanical ventilation after ASO. Risk factors included prematurity, post-CPB transfusion of salvaged red cells, platelets and cryoprecipitate, and postoperative fluid balance by univariate analysis. The larger transfused platelet volume was associated with the risk of ALI by multivariate analysis. The median baseline Brixia scores were 11.0 (9.0-12.0) and increased significantly in the postoperative day 1 in patients who developed moderate ALI 24 hours after admission to the intensive care unit (15.0 [13.0-16.0] v 12.0 [10.0-14.0], p = 0.046). CONCLUSIONS: Arterial switch operation results in a high incidence of ≥48-hour postoperative mechanical ventilation. Blood component transfusion is a potentially modifiable risk factor. The Brixia scores also may be used to characterize postoperative acute lung injury.

CD11a regulates hematopoietic stem and progenitor cells.

Integrin αLß2 (CD11a/CD18, CD11a) is a critical leukocyte adhesion molecule in leukocyte arrest and immunological synapse formation. However, its role in the bone marrow has not been investigated in depth. Here we showed that CD11a was expressed on all subsets of hematopoietic stem and progenitor cells (HPSCs). CD11a deficiency enhanced HSPCs activity under lipopolysaccharide (LPS) stimulation as demonstrated by a higher HSPC cell count along with an increase in cell proliferation. However, our mixed chimera experiment did not support that this phenotype was driven in a cell-intrinsic manner. Rather we found that the production of IL-27, a major cytokine that drives HSPC proliferation, was significantly upregulated both in vivo and in vitro. This adds a novel role of CD11a biology.

Narrative review of systemic inflammatory response mechanisms in cardiac surgery and immunomodulatory role of anesthetic agents.

Although surgical techniques and perioperative care have made significant advances, perioperative mortality in cardiac surgery remains relatively high. Single- or multiple-organ failure remains the leading cause of postoperative mortality. Systemic inflammatory response syndrome (SIRS) is a common trigger for organ injury or dysfunction in surgical patients. Cardiac surgery involves major surgical dissection, the use of cardiopulmonary bypass (CPB), and frequent blood transfusions. Ischemia-reperfusion injury and contact activation from CPB are among the major triggers for SIRS. Blood transfusion can also induce proinflammatory responses. Here, we review the immunological mechanisms of organ injury and the role of anesthetic regimens in cardiac surgery.

Perioperative prophylactic corticosteroids for cardiac surgery in children: A systematic review and meta-analysis.

OBJECTIVE: Perioperative corticosteroids have been used for pediatric cardiac surgery for decades, but the underlying evidence is conflicting. We aimed to investigate the efficacy and safety of perioperative prophylactic corticosteroids in pediatric heart surgeries. METHODS: We searched electronic databases until March 2023 to retrieve all randomized controlled trials (RCTs) that administered perioperative prophylactic corticosteroids to children undergoing heart surgery. We used RevMan 5.4 to pool risk ratios (RRs) and mean differences (MDs). RESULTS: A total of 12 RCTs (2,209 patients) were included in our review. Corticosteroids administration was associated with a nonsignificant reduction in all-cause mortality (RR 0.62; 95% CI: 0.37-1.02, I2 = 0%; moderate certainty); however, it was associated with a lower duration of mechanical ventilation (MV) (MD -0.63 days; 95% CI: -1.16 to -0.09 days, I2 = 41%; high certainty). Corticosteroids did not affect the length of ICU and hospital stay but significantly reduced the incidence of postoperative low cardiac output syndrome (LCOS) (RR 0.76; 95% CI: 0.60-0.96, I2 = 0%; moderate certainty) and reoperation (RR 0.37; 95% CI: 0.19-0.74, I2 = 0%; moderate certainty). There was no increase in adverse events except a higher risk of hyperglycemia and postoperative insulin use. CONCLUSIONS: The use of perioperative corticosteroids in pediatric heart surgeries is associated with a trend toward reduced all-cause mortality without attaining statistical significance. Corticosteroids reduced MV duration, and probably decrease the incidence of LCOS, and reoperations. The choice of corticosteroid agent and dose is highly variable and further larger studies may help determine the ideal agent, dose, and patient population for this prophylactic therapy.

Volatile anesthetic isoflurane exposure facilitates Enterococcus biofilm infection.

Enterococcus faecalis (E. faecalis) is one of the major pathogenic bacteria responsible for surgical site infections. Biofilm infections are major hospital-acquired infections. Previous studies suggested that ions could regulate biofilm formation in microbes. Volatile anesthetics, frequently administered in surgical setting, target ion channels. Here, we investigated the role of ion channels/transporters and volatile anesthetics in the biofilm formation by E. faecalis MMH594 strain and its ion transporter mutants. We found that a chloride transporter mutant significantly reduced biofilm formation compared to the parental strain. Downregulation of teichoic acid biosynthesis in the chloride transporter mutant impaired biofilm matrix formation and cellular adhesion, leading to mitigated biofilm formation. Among anesthetics, isoflurane exposure enhanced biofilm formation in vitro and in vivo. The upregulation of de novo purine biosynthesis pathway by isoflurane exposure potentially enhanced biofilm formation, an essential process for DNA, RNA, and ATP synthesis. We also demonstrated that isoflurane exposure to E. faecalis increased cyclic-di-AMP and extracellular DNA production, consistent with the increased purine biosynthesis. We further showed that isoflurane enhanced the enzymatic activity of phosphoribosyl pyrophosphate synthetase (PRPP-S). With the hypothesis that isoflurane directly bound to PRPP-S, we predicted isoflurane binding site on it using rigid docking. Our study provides a better understanding of the underlying mechanisms of E. faecalis biofilm formation and highlights the potential impact of an ion transporter and volatile anesthetic on this process. These findings may lead to the development of novel strategies for preventing E. faecalis biofilm formation and improving patient outcomes in clinical settings.

Surgical site infection in pediatric spinal fusion surgery revisited: outcome and risk factors after preventive bundle implementation.

Background: Surgical site infections (SSI) contribute to significant morbidity, mortality, length of stay, and financial burden. We sought to evaluate the incidence and risk factors of surgical site infection following pediatric spinal fusion surgery in patients for whom standard perioperative antibiotic prophylaxis and preventive strategies have been implemented. Methods: We conducted a retrospective study of children aged <18 years who underwent spinal fusion surgery from January 2017 to November 2021 at a quaternary academic pediatric medical center. Univariable analysis was used to evaluate associations between potential risk factors and SSI. Results: Of 1111 patients, 752 (67.6%) were female; median age was 14.2 years. SSI occurred in 14 patients (1.3%). Infections were superficial incisional (n=2; 14.3%), deep incisional (n=9; 64.3%), and organ/space (n=3; 21.4%). Median time to SSI was 14 days (range, 8 to 45 days). Staphylococcus aureus and Escherichia coli were the most frequently-isolated bacteria. Potential risk factors for SSIs included low body weight (Odds ratio (OR) 0.96, 95% confidence interval (CI) 0.93-0.99, p=0.026), ASA classification of ≥3 (OR 24.53, 95%CI 3.20-188.22, p=0.002), neuromuscular scoliosis (OR 3.83, 95%CI 3.82-78.32, p<0.001), prolonged operative time (OR 1.56, 95%CI 1.28-1.92, p<0.001), prolonged anesthetic time (OR 1.65, 95%CI 1.35-2.00, p<0.001), administration of prophylactic antibiotic ≥60 minutes before skin incision (OR 11.52, 95%CI 2.34-56.60, p=0.003), and use of povidone-iodine alone for skin preparation (OR 5.97, 95%CI 1.27-28.06, p=0.024). Conclusion: In the context of a robust bundle for SSI prevention; low body weight, ASA classification of ≥3, neuromuscular scoliosis, prolonged operative and anesthetic times, administration of prophylactic antibiotic ≥60 minutes before skin incision, and use of povidone-iodine alone for skin preparation increased the risk of SSI. Administration of prophylactic antibiotic within 60 minutes of skin incision, strict adherence to high-risk preventive protocol, and use of CHG-alcohol could potentially reduce the rate of SSI.

CD11c regulates neutrophil maturation.

Sepsis continues to be associated with high morbidity and mortality. Currently, sepsis is managed only conservatively. In sepsis, a substantial number of neutrophils is required, leading to accelerated neutrophil production. Immature neutrophils are released into the circulation to meet a demand, despite their less effective functioning in microbial eradication. Although an intervention to provide more mature neutrophils may serve as a potential sepsis treatment, the mechanism of neutrophil differentiation and maturation remains poorly understood. We discovered that CD11c, traditionally known as a dendritic cell marker, was expressed in neutrophils and regulated neutrophil maturation and effector functions. In the absence of CD11c, neutrophil maturation was impaired in the bone marrow, concomitant with a significant increase in the proliferation and apoptosis of preneutrophils, associated with less effector functions. Under lipopolysaccharide challenge, inducing an emergent neutrophil production in the bone marrow, CD11c deficiency exaggerated the release of immature neutrophils into the circulation, associated with a significant proliferation and apoptosis of preneutrophils. In contrast, constitutively active CD11c knock-in mice showed accelerated neutrophil maturation associated with enhanced effector functions, which further supports the notion that CD11c regulates neutrophil maturation. Furthermore, the constitutively active CD11c knock-in mice offered enhanced bacterial eradication. Taken together, we discovered that CD11c was critical for the regulation of neutrophil maturation, and CD11c activation could serve as a potential target for sepsis treatment.

Neutrophil extracellular traps formation is associated with postoperative complications in neonates and infants undergoing congenital cardiac surgery.

Pediatric patients with congenital heart diseases (CHD) often undergo surgical repair on cardiopulmonary bypass (CPB). Despite a significant medical and surgical improvement, the mortality of neonates and infants remains high. Damage-associated molecular patterns (DAMPs) are endogenous molecules released from injured/damaged tissues as danger signals. We examined 101 pediatric patients who underwent congenital cardiac surgery on CPB. The mortality rate was 4.0%, and the complication rate was 31.6%. We found that neonates/infants experienced multiple complications most, consistent with the previous knowledge. Neonates and infants in the complication group had received more transfusion intraoperatively than the non-complication arm with lower maximum amplitude (MA) on rewarming CPB thromboelastography (TEG). Despite TEG profiles were comparable at ICU admission between the two groups, the complication arm had higher postoperative chest tube output, requiring more blood transfusion. The complication group showed greater neutrophil extracellular traps (NETs) formation at the end of CPB and postoperatively. Plasma histones and high mobility group box 1 (HMGB1) levels were significantly higher in the complication arm. Both induced NETs in vitro and in vivo . As histones and HMGB1 target Toll-like receptor (TLR)2 and TLR4, their mRNA expression in neutrophils was upregulated in the complication arm. Taken together, NETs play a major role in postoperative complication in pediatric cardiac surgery and would be considered a target for intervention. Key points: Neonates and infants showed highest postoperative complications with more upregulation of inflammatory transcriptomes of neutrophils.Neonates and infants with organ dysfunction had more NETs formation with higher plasma histones and HMGB1 levels.

αDß2 as a novel target of experimental polymicrobial sepsis.

Since sepsis was defined three decades ago, it has been a target of intensive study. However, there is no specific sepsis treatment available, with its high mortality and morbidity. αDß2 (CD11d/CD18) is one of the four ß2 integrin members. Its role in sepsis has been limitedly studied. Using an experimental polymicrobial sepsis model, we found that the deficiency of αDß2 was associated with less lung injury and better outcome, which was in sharp contrast to other ß2 integrin member αLß2 (CD11a/CD18), and αMß2 (CD11b/CD18). This phenotype was supported by a reduction of bacterial loads in αDß2 knockout mice. Further analysis showed that the deficiency of αDß2 led to a reduction of neutrophil cell death as well as an increase in neutrophil phagocytosis in both murine and human systems. Our data showed a unique role of αDß2 among the ß2 integrin members, which would serve as a potential target to improve the outcome of sepsis.

Exploring Noncardiac Surgical Needs From Infancy to Adulthood in Patients With Congenital Heart Disease.

OBJECTIVES: As life expectancy for patients born with congenital heart disease (CHD) continues to rise, these patients will present increasingly for noncardiac surgery during childhood and adolescence. This study aimed to map the lifespan of noncardiac surgical needs among patients with CHD and explore how these needs may change over time. DESIGN: All patients with CHD presenting for noncardiac surgery between 2008 and 2014 were selected for review. SETTING: The study was conducted at a single urban academic tertiary pediatric hospital. PARTICIPANTS: All patients with CHD presenting for noncardiac surgery during the study period were included and grouped by cardiac diagnosis. INTERVENTIONS: Descriptive analysis included patient demographics, CHD diagnosis, procedures performed, and clinical data, including baseline saturation and underlying cardiac function. MEASUREMENTS AND MAIN RESULTS: A total of 3,011 noncardiac surgical procedures were performed on patients with CHD during the study period. The most common CHD diagnoses were patent ductus arteriosus (27.6%), ventricular septal defects (24.7%), and patent foramen ovale (24.3%). The median age was 4 years, 87% of all the patients were ≤10 years, and 41% had associated syndromes. Of the patients, 76% underwent a preoperative echocardiogram, and 10% had depressed cardiac function at the time of surgery. The most common procedures performed were ear, nose, and throat (20%), general surgery (14%), and radiology (11%). Intraoperative events were reported in 488 out of 3,010 encounters (16.2%), with the highest rates reported in patients with single-ventricle physiology (55/179; 30.7%). CONCLUSIONS: These findings suggested a greater burden of noncardiac surgery in lower age groups, with ear, nose, and throat and general surgery most common in young children and orthopedic and dental procedures increasing in adolescence.

The transcription factor FoxP3 can fold into two dimerization states with divergent implications for regulatory T cell function and immune homeostasis.

FoxP3 is an essential transcription factor (TF) for immunologic homeostasis, but how it utilizes the common forkhead DNA-binding domain (DBD) to perform its unique function remains poorly understood. We here demonstrated that unlike other known forkhead TFs, FoxP3 formed a head-to-head dimer using a unique linker (Runx1-binding region [RBR]) preceding the forkhead domain. Head-to-head dimerization conferred distinct DNA-binding specificity and created a docking site for the cofactor Runx1. RBR was also important for proper folding of the forkhead domain, as truncation of RBR induced domain-swap dimerization of forkhead, which was previously considered the physiological form of FoxP3. Rather, swap-dimerization impaired FoxP3 function, as demonstrated with the disease-causing mutation R337Q, whereas a swap-suppressive mutation largely rescued R337Q-mediated functional impairment. Altogether, our findings suggest that FoxP3 can fold into two distinct dimerization states: head-to-head dimerization representing functional specialization of an ancient DBD and swap dimerization associated with impaired functions.

The Role of Pulmonary Function Test in Perioperative Management of Patients with Cystic Fibrosis.

Cystic fibrosis (CF) is one of chronic illness affecting many different organs. Although the outcome of CF patients undergoing procedures was not favorable more than half a century ago, it showed a continuous improvement based on the previous reports. However, recent outcome report of CF patients' procedural outcomes is limited. We analyzed CF patients who underwent procedures from 2010 to 2020 in our institution. The mortality of 1,903 procedures performed in 430 CF patients was 0.74%, seen in high-risk procedures such as lung transplantation. We also analyzed the perioperative profiles of CF patients who underwent functional endoscopic sinus surgery (FESS). We identified the preoperative pulmonary function testing result to be predictive of postoperative hospital stay.

CCR6 and CXCR6 Identify the Th17 Cells With Cytotoxicity in Experimental Autoimmune Encephalomyelitis.

Due to the plasticity of IL-17-producing CD4 T cells (Th17 cells), a long-standing challenge in studying Th17-driven autoimmune is the lack of specific surface marker to identify the pathogenic Th17 cells in vivo. Recently, we discovered that pathogenic CD4 T cells were CXCR6 positive in experimental autoimmune encephalomyelitis (EAE), a commonly used Th17-driven autoimmune model. Herein, we further revealed that peripheral CXCR6+CD4 T cells contain a functionally distinct subpopulation, which is CCR6 positive and enriched for conventional Th17 molecules (IL-23R and RORγt) and cytotoxic signatures. Additionally, spinal cord-infiltrating CD4 T cells were highly cytotoxic by expressing Granzyme(s) along with IFNγ and GM-CSF. Collectively, this study suggested that peripheral CCR6+CXCR6+CD4 T cells were Th17 cells with cytotoxic property in EAE model, and highlighted the cytotoxic granzymes for EAE pathology.

The Characterization of Postoperative Mechanical Respiratory Requirement in Neonates and Infants Undergoing Cardiac Surgery on Cardiopulmonary Bypass in a Single Tertiary Institution.

OBJECTIVES: Although neonates and infants undergoing cardiac surgery on cardiopulmonary bypass (CPB) are at high risk of developing perioperative morbidity and mortality, including lung injury, the intraoperative profile of lung injury in this cohort is not well-described. Given that the postoperative course of patients in the pediatric cardiac surgical arena has become increasingly expedited, the objective of this study was to characterize the profiles of postoperative mechanical ventilatory support in neonates and infants undergoing cardiac surgery on CPB and to examine the characteristics of lung mechanics and lung injury in this patient population who are potentially amendable to early postoperative recovery in a single tertiary pediatric institution. DESIGN: A retrospective data analysis of neonates and infants who underwent cardiac surgery on cardiopulmonary bypass. SETTING: A single-center, university teaching hospital. PARTICIPANTS: The study included 328 neonates and infants who underwent cardiac surgery on cardiopulmonary bypass. INTERVENTIONS: A subset of 128 patients were studied: 58 patients undergoing ventricular septal defect (VSD) repair, 36 patients undergoing complete atrioventricular canal (CAVC) repair, and 34 patients undergoing bidirectional Glenn (BDG) shunt surgery. MEASUREMENTS AND MAIN RESULTS: Of the entire cohort, 3.7% experienced in-hospital mortality. Among all surgical procedures, VSD repair (17.7%) was the most common, followed by CAVC repair (11.0%) and BDG shunt surgery (10.4%). Of patients who underwent VSD repair, CAVC repair, and BDG shunt surgery, 65.5%, 41.7%, and 67.6% were off mechanical ventilatory support within 24 hours postoperatively, respectively. In all three of the surgical repairs, lung compliance decreased after CPB compared to pre-CPB phase. Sixty point three percent of patients with VSD repair and 77.8% of patients with CAVC repair showed a PaO2/FIO2 (P/F) ratio of <300 after CPB. Post- CPB P/F ratios of 120 for VSD patients and 100 for CAVC patients were considered as optimal cutoff values to highly predict prolonged (>24 hours) postoperative mechanical ventilatory support. A higher volume of transfused platelets also was associated with postoperative ventilatory support ≥24 hours in patients undergoing VSD repair, CAVC repair, and BDG shunt surgery. CONCLUSIONS: There was a high incidence of lung injury after CPB in neonates and infants, even in surgeries amendable for early recovery. Given that CPB-related factors (CPB duration, crossclamp time) and volume of transfused platelet were significantly associated with prolonged postoperative ventilatory support, the underlying cause of cardiac surgery-related lung injury can be multi-factorial.

The Role of General Anesthetic Drug Selection in Cancer Outcome.

Cancer remains to be the leading cause of death globally. Surgery is a mainstay treatment for solid tumors. Thus, it is critical to optimize perioperative care. Anesthesia is a requisite component for surgical tumor resection, and general anesthesia is given in the vast majority of tumor resection cases. Because anesthetics are growingly recognized as immunomodulators, it is critical to optimize anesthetic regimens for cancer surgery if the selection can affect outcomes. Here, we reviewed the role of volatile and intravenous anesthesia used for cancer surgery in cancer recurrence.

The Role of Anesthetic Selection in Perioperative Bleeding.

Perioperative bleeding is one of the major comorbidities associated with surgery. While anesthesia is a critical component to perform surgery, a number of clinical studies supported the contribution of anesthetic drugs to perioperative bleeding. Here, we reviewed the literature on this topic including the underlying mechanism and discussed the future direction on coagulation research in anesthesia.

The immunomodulatory mechanism of dexmedetomidine.

Dexmedetomidine has been increasingly introduced into the perioperative care of surgical patients. Because a subset of anesthetics/sedatives are immunomodulatory, it is critical to understand the role of dexmedetomidine in our host immune functions. Here we reviewed the role of dexmedetomidine in different immune cells. We also reviewed published clinical articles that described the role of dexmedetomidine in organ injury, cancer surgery, and infection. In animal studies, dexmedetomidine attenuated organ injury. In clinical studies, dexmedetomidine was associated with an improvement in outcomes in cardiac surgery and transplant surgery. However, there is a paucity in research examining how dexmedetomidine is associated with these outcomes. Further studies are needed to understand its clinical application from immunological standpoints.

Risk factors for pediatric surgical site infection following neurosurgical procedures for hydrocephalus: a retrospective single-center cohort study.

BACKGROUND: Infection is a major complication following cerebral spinal fluid (CSF) diversion procedures for hydrocephalus. However, pediatric risk factors for surgical site infection (SSI) are currently not well defined. Because a SSI prevention bundle is increasingly introduced, the purpose of this study was to evaluate risk factors associated with SSIs following CSF diversion surgeries following a SSI bundle at a single quaternary care pediatric hospital. METHODS: We performed a retrospective cohort study of patients undergoing CSF diversion procedures from 2017 to 2019. SSIs were identified prospectively through continuous surveillance. We performed unadjusted logistic regression analyses and univariate analyses to determine an association between SSIs and patient demographics, comorbidities and perioperative factors to identify independent risk factors for SSI. RESULTS: We identified a total of 558 CSF diversion procedures with an overall SSI rate of 3.4%. The SSI rates for shunt, external ventricular drain (EVD) placement, and endoscopic third ventriculostomy (ETV) were 4.3, 6.9 and 0%, respectively. Among 323 shunt operations, receipt of clindamycin as perioperative prophylaxis and presence of cardiac disease were significantly associated with SSI (O.R. 4.99, 95% C.I. 1.27-19.70, p = 0.02 for the former, and O.R. 7.19, 95% C.I. 1.35-38.35, p = 0.02 for the latter). No risk factors for SSI were identified among 72 EVD procedures. CONCLUSION: We identified receipt of clindamycin as perioperative prophylaxis and the presence of cardiac disease as risk factors for SSI in shunt procedures. Cefazolin is recommended as a standard antibiotic for perioperative prophylaxis. Knowing that unsubstantiated beta-lactam allergy label is a significant medical problem, efforts should be made to clarify beta-lactam allergy status to maximize the number of patients who can receive cefazolin for prophylaxis before shunt placement. Further research is needed to elucidate the mechanism by which cardiac disease may increase SSI risk after shunt procedures.