Prevalence of enterococcal groin colonization in patients undergoing cardiac interventions: challenging antimicrobial prophylaxis with cephalosporins in patients undergoing transcatheter aortic valve replacement.

BACKGROUND: Cephalosporins are recommended for prophylaxis before transcatheter aortic valve replacement (TAVR). Infective endocarditis (IE) after TAVR is caused by enterococci in up to 30% of cases, particularly early after TAVR. Enterococcal colonization in the groin has been postulated as a source of infection, not only because prophylaxis does not cover enterococci but also because most TAVR procedures are performed by transfemoral access. There are few data analysing the groin microbiome to demonstrate the presence of enterococci. AIM: To assess the prevalence of enterococci in the groins of cardiological patients receiving transfemoral interventions. METHODS: This prospective cohort study was undertaken at University Hospital Basel, Switzerland between February and August 2020. Two skin swabs were taken from the groins of consecutive patients undergoing transfemoral cardiac interventions before the administration of antibiotic prophylaxis; for each patient, swabs were taken before and after groin disinfection. Swabs were analysed in the local microbiological laboratory following validated culture methods. FINDINGS: Of 290 included patients, 245 (84.5%) underwent coronary angiography, 31 (10.7%) underwent TAVR, eight (2.8%) underwent right heart catheterization, five (1.7%) underwent closure of patent foramen ovale, and one (0.3%) underwent a MitraClip procedure. Enterococci were detected before disinfection in 48 patients, enterococci were still cultured after disinfection in three patients, and enterococci were detected after disinfection alone (i.e. not detected before disinfection) in one patient. The prevalence of enterococci was 16.6% before disinfection and 1.4% after disinfection. Patients colonized with enterococci had a significantly higher body mass index and were more likely to be diabetic than uncolonized patients. CONCLUSION: Common enterococcal colonization of the groin, coupled with frequent isolation of enterococci from patients with TAVR-associated IE, provides strong evidence that the current recommendation of antimicrobial prophylaxis with cephalosporins before TAVR should be changed to antimicrobial prophylaxis with a compound that is active against enterococci.

Does high adherence to contact precautions lead to low in-hospital transmission of multi-drug-resistant micro-organisms in the endemic setting?

BACKGROUND: Conflicting results have been published on the impact of contact precautions (CPs) on reduction of transmission of multi-drug-resistant micro-organisms (MDROs) in the endemic setting. Ambiguous definitions coupled with low adherence partly explain these differences. AIM: We prospectively monitored the level of adherence to CPs and aimed to relate it to in-hospital transmission of MDROs. METHODS: Between January 2016 and March 2018, all patients under CPs underwent continuous monitoring of adherence to CPs by routine on-site visits on days 0, 3 and 7 after initiating CPs using a standardized checklist. The protocol included 10 interventions that were routinely checked such as CP sign at the door as well as wearing of gowns and gloves upon entry to the patient room. Patients requiring CPs were defined as colonized or infected with MDROs (meticillin-resistant Staphylococcus aureus (MRSA), non-Escherichia coli extended-spectrum beta lactamase (ESBL) Enterobacterales, vancomycin-resistant enterococci (VRE) and carbapenem-resistant Gram-negative micro-organisms (CRGN)) as well as patients infected with respiratory viruses, norovirus, scabies and hypervirulent strains of Clostridioides difficile. FINDINGS: Overall, data from 13,756 CP records from 1378 visits of 812 patients were analysed. Adherence varied between 93% and 100% for each intervention, except for "separate space for contaminated material" with an adherence of 5.3-6.1%. The incidence of in-hospital transmission during the study period was extremely low for MRSA, VRE, non-E.coli ESBL Enterobacterales and CRGN with 0.00-0.064 cases/1000 patient days. CONCLUSION: High adherence coupled with continuous monitoring of CPs correlated with a very low in-hospital transmission rate. These results indicate that CPs are highly effective if routine monitoring of adherence is implemented.

Impact of an infection control service in a university psychiatric hospital: significantly lowering healthcare-associated infections during 18 years of surveillance.

BACKGROUND: Healthcare-associated infections (HAIs) lead to high morbidity and mortality. Data for HAIs in psychiatric hospitals are scarce, and are not derived from long-term surveillance. AIM: To assess the impact of an infection control service on the prevalence of HAIs in a psychiatric hospital over an 18-year period. METHODS: In 1999, a professional infection control service was initiated at the University Psychiatric Hospital in Basel, Switzerland, with a part-time infection control nurse, a hospital epidemiologist, and administrative support. In addition to monitoring rates of multi-drug-resistant pathogens, eight prevalence studies using definitions outlined by the Centers for Disease Control and Prevention (CDC) were conducted between 2001 and 2018. For the primary outcome, a Poisson regression model was fitted to confirm cases of HAIs, standardized for patients at risk as a model offset. FINDINGS: Overall, the predicted prevalence of nosocomial infections decreased from 3.7% (95% confidence interval (CI) 2.2-5.3%) in 2001 to 1.0% (95% CI 0.2-1.8%) in 2018 after introduction of an infection control service (incidence ratio rate (IRR) for yearly decrease of 0.93, 95% CI 0.87-0.98, P=0.007). CONCLUSIONS: Implementation of an infection control service may lead to a significant long-term decrease in HAIs, even in an institution caring for patients with low risk for HAIs, such as in psychiatric hospitals. In addition, epidemics and clusters were rapidly contained. Infection control services from acute-care hospitals should be expanded to psychiatric institutions, in order to decrease the incidence of HAIs and meet new challenges in times of emergence of multi-drug-resistant pathogens.

Time-dependent differences in management and microbiology of orthopaedic internal fixation-associated infections: an observational prospective study with 229 patients.

OBJECTIVES: Little information has been published on orthopaedic internal fixation-associated infections. We aimed to analyse time-dependent microbiology, treatment, and outcome. METHODS: Over a 10-year period, all consecutive patients with internal fixation-associated infections at the University Hospital of Basel, were prospectively followed and clinical, microbiological and outcome data were acquired. Infections were classified as early (0-2 weeks after implantation), delayed (3-10 weeks), and late (>10 weeks). RESULTS: Two hundred and twenty-nine patients were included, with a median follow-up of 773 days (IQR 334-1400). Staphylococcus aureus was the most prevalent pathogen (in 96/229 patients, 41.9%). Enterobacteriaceae were frequent in early infections (13/49, 26.5%), whereas coagulase-negative staphylococci (36/92, 39.1%), anaerobes (15/92, 16.3%) and streptococci (10/92, 10.9%) increased in late revisions. Failure was observed in 27/229 (11.7%). Implants were retained in 42/49 (85.7%) in early, in 51/88 (57.9%) in delayed, and in 9/92 (9.8%) in late revisions (p < 0.01). Early revisions failed in 6/49 (12.2%), delayed in 9/88 (10.2%), and late in 11/92 (13.0%) (p 0.81). Debridement and retention failed in 6/42 (14.3%) for early, in 6/51 (11.8%) for delayed, and in 3/9 (33.3%) for late revisions (p 0.21). Biofilm-active antibiotic therapy tailored to resistance correlated with improved outcome for late revisions failure (6/72, 7.7% versus 6/12, 50.0%; p < 0.01) but not for early revisions failure (5/38, 13.2% versus 1/11, 9.1%; p 1.0). CONCLUSIONS: Treatment of internal fixation-associated infections showed a high success rate of 87-90% over all time periods. Implant retention was highly successful in early and delayed infections but only limited in late infections.

Workload even affects hand hygiene in a highly trained and well-staffed setting: a prospective 365/7/24 observational study.

INTRODUCTION: Compliance with hand hygiene (HH) has often not proved satisfactory; high workload is a commonly self-reported reason. Previous studies comparing workload and compliance have not measured workload precisely and have focused on certain times of day. This study aimed to investigate the association between HH compliance and workload, both electronically defined 365/7/24 (primary endpoint). In addition, the quality of commonly used compliance defining methods (hand disinfectant usage, direct observation) was investigated (secondary endpoint). MATERIALS AND METHODS: Correlation of electronically measured HH compliance (hand-rub activities (HRA)/HH opportunities) with electronically determined workload (nursing time output/nursing time input) was undertaken over one year at a stem cell transplant unit at University Hospital Basel, Switzerland. HRA and procedures requiring HRA according to the five World Health Organization indications were recorded continuously (365/7/24) using electronic dispensers and electronic documentation, and compliance was calculated accordingly. Hand disinfectant usage was calculated using spending records for one year; direct observation was performed for approximately 1800 HH opportunities. RESULTS: During the investigation, 208,184 HRA, translating into 57 [standard deviation (SD) 10] HRA/patient-day (PD), were performed. Electronically determined compliance ranged from 24% to 66% [mean 42.39% (SD 8%)]. The higher the workload, the lower the compliance (R=-0.411; P<0.001). HRA/PD (r=-0.037), hand disinfectant usage (mean 160mL/PD) and observed compliance (95%; 1734 HRA/1813 HH opportunities) were not found to be associated with workload. CONCLUSION: Calculated compliance was inversely associated with nurses' workload. HRA/PD, observer-determined compliance and amount of disinfectant dispensed were used as surrogates for compliance, but did not correlate with actual compliance and thus should be used with caution.

Validation of a treatment algorithm for orthopaedic implant-related infections with device-retention-results from a prospective observational cohort study.

Success rates for treatment regimens involving retention of an infected implant are conflicting and failure rates of up to 80% have been reported. We aimed to validate a proposed treatment algorithm, based on strict selection criteria, by assessing long-term outcome of treatment for orthopaedic device-related infection (ODRI) with retention. From January 1999 to December 2009, all patients diagnosed with ODRI at the University Hospital Basel, Switzerland were eligible for treatment with open surgical debridement, implant-retention and antibiotics, if duration of clinical symptoms was ≤3 weeks, the implant was stable, the soft-tissue had no abscess or sinus tract, and the causative pathogen was susceptible to antimicrobial agents with activity against surface-adhering microorganisms. Antimicrobial treatment was administered according to a predefined algorithm. The primary outcome was treatment failure after 2-year follow up. A total of 455 patients were diagnosed with an ODRI, of whom 233 (51.2%) patients were eligible for treatment involving implant-retention. Causative pathogens were mainly Staphylococcus aureus (41.6%) and coagulase-negative staphylococci (33.9%). Among patients with ODRIs related to prostheses, failure was documented in 10.8% (12/111) and in patients with ODRIs related to osteosyntheses, failure occurred in 9.8% (12/122) after 2 years of follow up. In all, 90% of ODRIs were successfully cured with surgical debridement and implant-retention in addition to long-term antimicrobial therapy according to a predefined treatment algorithm: if patients fulfilled strict selection criteria and there was susceptibility to rifampin for Gram-positive pathogens and ciprofloxacin for Gram-negative pathogens.

Low sensitivity of fecal toxin A/B enzyme immunoassay for diagnosis of Clostridium difficile infection in immunocompromised patients.

The optimal approach in laboratory diagnosis of Clostridium difficile infection (CDI) is still not well defined. Toxigenic culture (TC) or alternatively fecal toxin assay by cell cytotoxicity neutralization assay are considered to be the reference standard, but these methods are time-consuming and labor intensive. In many medical centers, diagnosis of CDI is therefore still based on fecal toxin A/B enzyme immunoassay (EIA) directly from stool alone, balancing cost and speed against limited diagnostic sensitivity. The aim of the study was to assess in which patient population the additional workload of TC is justified. All consecutive stool specimens submitted for diagnosis of suspected CDI between 2004 and 2011 at a tertiary-care center were examined by toxin EIA and TC. Clinical data of patients with established diagnosis of CDI were collected in a standardized case-report form. From 12,481 stool specimens submitted to the microbiologic laboratory, 480 (3.8%) fulfilled CDI criteria; 274 (57.1%) were diagnosed by toxin EIA; and an additional 206 (42.9%) were diagnosed by TC when toxin EIA was negative. Independent predictors for negative toxin EIA but positive TC were high-dose corticosteroids (odds ratio (OR) 2.97, 95% confidence interval (CI) 1.50-5.90, p 0.002), leukocytopenia <1000/µL (OR 2.52, 95% CI 1.22-5.23, p 0.013) and nonsevere CDI (OR 2.21, 95% CI 1.39-3.50, p 0.001). There was no difference in outcomes such as in-hospital mortality and recurrence between both groups. In conclusion, negative toxin EIA does not rule out CDI in immunocompromised patients in the setting of relevant clinical symptoms. Methods with improved sensitivity such as TC or PCR should be used, particularly in this patient population.

Is admission screening for Pseudomonas aeruginosa useful in haematologic patients? A prospective study with 1310 patients.

Screening for Pseudomonas aeruginosa is recommended to guide empirical antimicrobial therapy in patients on high-risk units. However, evidence for this approach is scarce. We therefore screened 1310 patients with severe haematologic diseases for P. aeruginosa colonization at admission: 108 (8.2%) were positive, but only nine (0.7%; six with the same clone as in the screening isolate) subsequently developed a P. aeruginosa bloodstream infection (positive predictive value of screening, 8.6%; negative predictive value of screening, 99.5%). Routine screening for P. aeruginosa at admission did not sufficiently predict subsequent bloodstream infections caused by P. aeruginosa.

Rectal swab for detection of norovirus by real-time PCR: similar sensitivity compared to faecal specimens.

Rapid diagnosis and immediate infection control precautions are cornerstones in the prevention of norovirus outbreaks. However, faecal sampling for norovirus PCR--the standard of care--is time consuming. From 2009 to 2011, parallel faecal and rectal swab samples were consecutively obtained from patients with acute gastroenteritis presenting at our emergency department. In total, 109 complete sample pairs of 108 patients were analysed by specific norovirus real-time PCR. The sensitivity of real-time PCR was 97.3% (36/37) for both sampling methods. A rectal swab is a reasonable option for detection of norovirus by real-time PCR, if a stool specimen is not readily available.

How to discriminate contamination from bloodstream infection due to coagulase-negative staphylococci: a prospective study with 654 patients.

Coagulase-negative staphylococci (CoNS) are frequent contaminants of blood cultures. We aimed to evaluate the systemic inflammatory response syndrome (SIRS) criteria in patients with CoNS bacteraemia for discrimination between true bloodstream infection (BSI) and contamination. Prospective evaluation was carried out of clinical and laboratory parameters in adults with at least one positive blood culture with CoNS at the University Hospital of Basel between 2003 and 2007. Of 3060 positive blood cultures, 654 episodes of CoNS bacteraemia were identified. Of these, 232 (35%) were considered to be true BSI and 422 (65%) were considered to be contamination. Overall, 80% of study participants had at least one SIRS criterion, fever being the most common, and 49% had at least two SIRS criteria. In the multivariate analysis, independent predictors of BSI were fever or hypothermia (OR 2.93, 95% CI 1.91-4.5), tachycardia (OR 2.29, 95% CI 1.50-3.50), tachypnoea (OR 2.4, 95% CI 1.30-4.43), leucocytosis or leucopenia (OR 4.15, 95% CI 2.17-6.36) and the presence of a central venous line (OR 5.38, 95% CI 3.25-8.88). The probability of BSI increased with each additional SIRS criterion, ranging from 42.4% in patients with only one SIRS criterion to 56.7% for those with two criteria, and 72.3% for patients with three SIRS criteria. A positive blood culture with CoNS most likely represents true BSI if the patient has at least three SIRS criteria or two SIRS criteria and a central venous catheter. These simple bedside criteria may guide decision to treat, decreasing the use of glycopeptides.

Not all patients with vancomycin-resistant enterococci need to be isolated.

BACKGROUND: Vancomycin-resistant enterococci (VRE) have triggered multiple outbreaks. However, VRE of genotype vanC appear not to be associated with outbreaks. The goal of this study was to estimate the risk of bloodstream infections in patients colonized with VRE of genotype vanC who received care from a bone marrow transplant unit for patients with leukemia, where only standard precautions were implemented for VRE of genotype vanC during the last 9 years. METHODS: Since 2000, all patients in the bone marrow transplant unit underwent routine VRE rectal screening, data were prospectively entered in a database, and isolates were molecularly characterized. Infection control policy required contact isolation for patients infected with VRE of genotype vanA or vanB but only standard precautions for patients infected with VRE of genotype vanC. RESULTS: From January 2000 to July 2008, 290 isolates of VRE of genotype vanC obtained from 273 different patients were identified, with an incidence of 25-43 isolates/year. Of 290 isolates, 285 (98%) were identified in rectal screening swabs, 5 were from other body sites, and none required specific treatment. During the entire study period, only 1 case of bloodstream infection was detected, reflecting an incidence of 1 (0.4%) of the 273 patients, or <0.2 cases per 1000 patient-days. No outbreaks were recorded. CONCLUSIONS: These data provide strong evidence that carriers of VRE of genotype vanC do not require contact isolation, thereby saving resources and potentially improving patient care. The genotype should be routinely determined in areas with a high prevalence of VRE of genotype vanC.

Surveillance of surgical site infections by surgeons: biased underreporting or useful epidemiological data?

Surgical site infections (SSIs) significantly increase post-operative morbidity and mortality. SSI surveillance is an established monitoring tool and reduces SSI rates. The purpose of this study was to compare prospective in-hospital SSI surveillance (I) by the surgical staff and (II) additionally by an infection control team (ICT). The reference method (III) was defined by data generated by the surgical team, supplemented by the ICT and completed by post-discharge surveillance with a post-operative follow-up of one year representing the sum of all available resources. During 24 months, all consecutive inpatient procedures (N=6283) were prospectively recorded by the surgical staff until patients' discharge (I). SSI rates were compared with the surveillance performed by the ICT (II) and with the reference method (III). The overall SSI rate (reference method) was 4.7% (N=293), of which 187 (63.8%) were detected in-hospital and 106 (36.2%) after discharge. (I) The surgical staff detected 91/187 (48.7%) of in-hospital SSIs [91/293 (31.0%) of the reference], (II) the ICT an additional 96/187 (51.3%) during hospitalisation [96/293 (32.8%) of the reference]. Further cross-checking as performed in the visceral surgery department increased the surgeons' detection rate (I) to 59/105 (56.2%) of in-hospital SSIs [59/147 (40.1%) of the reference]. SSI surveillance by the surgical staff detects almost half of all in-hospital SSIs and has the potential to increase the detection rate by simple interventions such as cross-checking. Such a relatively inexpensive surveillance system is an option for hospitals without an ICT or for low risk surgical procedures. Moreover, trends in SSI rates can easily be detected, allowing early intervention.

First wave of the influenza A/H1N1v pandemic in Switzerland.

AIM: To describe the disease burden, clinical pattern and outcome of influenza-related cases presenting to a Swiss Emergency Department (ED), during the first wave of the 2009 pandemic. METHODS: Retrospective analysis of prospectively collected data at the University Hospital of Basel, Switzerland. All patients presenting to the ED with influenza-like symptoms from June 1 to October 23, 2009, were studied. Rate of hospitalisation, demographic characteristics, symptoms, microbiological diagnoses and complications of influenza infection were analysed. RESULTS: One tenth (808 of 8356 patients) of all non-trauma ED presentations, during the study period, were a result of suspected influenza-related illness. Influenza A/H1N1v infection accounted for 5% of these presentations. Patients aged 50 years or less accounted for 87% of these presentations and for 100% of A/H1N1v infection. The highest detection rate of A/H1N1v-infection occurred in July, and the highest rate of clinical presentations occurred in August 2009. Underlying medical disease was observed in 14% of all patients. The presence of fever, cough and myalgia was the prime clinical predictor for the presence of A/H1N1v infection. 16% of patients with this triad suffered from A/H1N1v. CONCLUSION: Suspected A/H1N1v infection contributed to a considerable health care burden in Switzerland. However, the rate of true positivity was low (5%), hospitalisations rare (5%), and mortality did not occur. Therefore, the first wave of the A/H1N1v pandemic in Switzerland was rather media "hype" than real threat.

Epidemiology of Clostridium difficile-associated disease at University Hospital Basel including molecular characterisation of the isolates 2006-2007.

A prospective study was conducted during a one-year period between 2006 and 2007 to describe the epidemiology of Clostridium difficile-associated disease (CDAD) at University Hospital Basel, Switzerland (UHBS) and to determine phenotypic and genotypic features of C. difficile strains isolated at the Microbiology Laboratory UHBS including strains from regional non-university hospitals. We prospectively identified 78 CDAD cases at UHBS with an incidence of 2.65/1,000 hospitalised patients or 2.3/10,000 patient-days. Sixteen patients (20.5%) were infected with clindamycin-resistant strains of PCR-ribotype 027 during an outbreak at the geriatric hospital. Among 124 single-patient isolates, 28 (22.6%) were resistant to moxifloxacin and 34 (27.4%) were resistant to clindamycin, but all remained susceptible to metronidazole and vancomycin. Of 102 toxigenic isolates, 19 (18.7%) had an 18-bp deletion in the tcdC gene, eight (7.8%) a 39-bp deletion, and one (1.0%) a 54-bp deletion. Genes for binary toxin were present in 27 (21.8%). PCR-ribotype 027 was associated with older age (median age 83.5 vs. 65.5 years, p < 0.0001) and longer duration of hospitalisation before onset of disease (median 15.5 vs. 9 days, p = 0.014) with a trend towards higher crude mortality, more severe disease, and previous use of macrolides compared to ribotype non-027. Overall, severe disease correlated with use of a nasogastric tube and surprisingly shorter duration of hospitalisation before onset of disease. Today, laboratory-based and epidemiological surveillance systems are required to monitor CDAD cases and emergence of new epidemic strains.

Highly effective regimen for decolonization of methicillin-resistant Staphylococcus aureus carriers.

OBJECTIVE: To evaluate the efficacy of a standardized regimen for decolonization of methicillin-resistant Staphylococcus aureus (MRSA) carriers and to identify factors influencing decolonization treatment failure. DESIGN: Prospective cohort study from January 2002 to April 2007, with a mean follow-up period of 36 months. SETTING: University hospital with 750 beds and 27,000 admissions/year. PATIENTS: Of 94 consecutive hospitalized patients with MRSA colonization or infection, 32 were excluded because of spontaneous loss of MRSA, contraindications, death, or refusal to participate. In 62 patients, decolonization treatment was completed. At least 6 body sites were screened for MRSA (including by use of rectal swabs) before the start of treatment. INTERVENTIONS: Standardized decolonization treatment consisted of mupirocin nasal ointment, chlorhexidine mouth rinse, and full-body wash with chlorhexidine soap for 5 days. Intestinal and urinary-tract colonization were treated with oral vancomycin and cotrimoxazole, respectively. Vaginal colonization was treated with povidone-iodine or, alternatively, with chlorhexidine ovula or octenidine solution. Other antibiotics were added to the regimen if treatment failed. Successful decolonization was considered to have been achieved if results were negative for 3 consecutive sets of cultures of more than 6 screening sites. RESULTS: The mean age (+/- standard deviation [SD]) age of the 62 patients was 66.2 +/- 19 years. The most frequent locations of MRSA colonization were the nose (42 patients [68%]), the throat (33 [53%]), perianal area (33 [53%]), rectum (36 [58%]), and inguinal area (30 [49%]). Decolonization was completed in 87% of patients after a mean (+/-SD) of 2.1 +/- 1.8 decolonization cycles (range, 1-10 cycles). Sixty-five percent of patients ultimately required peroral antibiotic treatment (vancomycin, 52%; cotrimoxazole, 27%; rifampin and fusidic acid, 18%). Decolonization was successful in 54 (87%) of the patients in the intent-to-treat analysis and in 51 (98%) of 52 patients in the on-treatment analysis. CONCLUSION: This standardized regimen for MRSA decolonization was highly effective in patients who completed the full decolonization treatment course.

New minimally invasive surgical technique using arterial T-grafts for treatment of double-vessel coronary artery disease: experimental study.

Minimally invasive surgery has been used successfully in patients with single-vessel coronary artery disease (CAD), but there are no clinical reports of surgical techniques for the treatment of multivessel disease in this field using both internal mammary arteries (IMAs). Therefore a canine model has been established to demonstrate the feasibility of a minimally invasive surgical treatment of coronary artery double-vessel disease using both IMAs. Ten mongrel dogs underwent bilateral thoracoscopic preparation of both internal mammary arteries through small left lateral chest ports. Using the Port Access endovascular cardiopulmonary bypass system the right IMA (RIMA) was anastomosed as a free graft end-to-side to the left IMA (LIMA) as a T-graft. After induction of cardioplegic arrest the RIMA was anastomosed to the circumflex artery and the LIMA to the left anterior descending artery. All animals were weaned from cardiopulmonary bypass without inotropic support. The electrocardiogram showed sinus rhythm with no signs of ischemia. Intraoperative coronary angiography demonstrated patency of all anastomoses. The minimally invasive surgical treatment of double-vessel CAD using arterial T-grafts of both IMAs is thus feasible. Surgical trauma can be further reduced by harvesting the RIMA transmediastinally through the left lateral chest.

Minimally invasive mitral valve surgery--clinical experiences with a PortAccess system.

OBJECTIVE: This is the initial experience with a new minimally invasive surgical technique for the treatment of mitral valve disease using a PortAccess system. METHODS: Between May 1996 and May 1997, 21 patients (nine male, 12 female, aged 30-75 years, median 64 years) underwent minimally invasive mitral valve surgery. The underlying diseases were: mitral valve insufficiency (n = 11), mitral valve stenosis (n = 5) and combined mitral valve disease (n = 5). Through a small right thoracotomy (6-8 cm) access to the pericardium and the heart was gained. Cardiopulmonary bypass was instituted through femoral cannulation and an intraaortic balloon-catheter (Heartport Inc., Redwood City, CA) was introduced for aortic occlusion, aortic root venting and delivery of cold crystalloid cardioplegia. Mitral valve repair (four patients) or replacement (15 patients) was performed. RESULTS: There was no death during the whole follow-up period. There was no perivalvular leak and only minor residual mitral valve regurgitation was observed on intraoperative or postoperative (3 months) transesophageal echocardiography. There was no postoperative study-related complication. Time of ventilation, intensive care unit and hospital-stay were comparable with the data of patients undergoing conventional mitral valve surgery. CONCLUSIONS: This technique of PortAccess mitral valve surgery combines the advantage of less invasive operative trauma with the safety of conventional mitral valve surgery.

Clinical experiences with minimally invasive mitral valve surgery using a simplified Port Access technique.

OBJECTIVE: Using the initial experiences with the Port-Access technique for the treatment of mitral valve disease some changes were made thus resulting in more simple and faster procedures. METHODS: Twenty-nine patients (13 male, 16 female, aged 30 to 75 years, median 62.5 +/- 11.0 years) underwent minimally invasive mitral valve surgery between May 1996 and December 1997. The underlying diseases were: mitral valve insufficiency (n = 16), mitral valve stenosis (n = 7) and combined mitral valve disease (n = 6). Through a small right thoracotomy (5-7 cm) access to the pericardium and the heart was gained. Cardiopulmonary bypass was instituted through femoral cannulation and an intraaortic balloon-catheter was introduced for aortic occlusion, aortic root venting and delivery of cold crystalloid cardioplegia. Mitral valve repair (five patients) or replacement (24 patients) was performed. RESULTS: There was no death during the whole follow-up period. There was no perivalvular leak and only minor residual mitral valve regurgitation was observed on intraoperative or postoperative (3 months) transesophageal echocardiography in three patients. There was no postoperative study-related complication. Time of ventilation and intensive care unit were comparable with the data of patients undergoing conventional mitral valve surgery but hospital stay was shorter in the last 10 consecutive cases. CONCLUSIONS: This simplified technique of mitral valve surgery combines the advantage of less invasive operative and good cosmetic results with the safety of conventional mitral valve surgery. At our institution this technique presents in well selected patients suffering from mitral valve disease the procedure of choice.