Home blood pressure self-measurement: “Current situation and new perspectives” / Automedidas domiciliarias de presión arterial: «situación actual y nuevas perspectivas»

The method typically used to diagnose and monitor hypertensive patients has been to measure blood pressure in the physician's surgery; however, it is a well-known fact that this approach poses certain drawbacks, such as observer bias, failure to detect an alert reaction in the clinic, etc., difficulties that affect its accuracy as a diagnostic method.In recent years, the varying international scientific societies have persistently recommended the use of blood pressure measurements outside the clinic (at home or in the outpatient setting), using validated automatic devices. Data from some studies suggest that if we rely solely on in-office measurements, approximately 15–20% of the time we may be wrong when making decisions, both in terms of diagnosis and patient follow-up.Home blood pressure measurements are a simple and very affordable method that has a similar reproducibility and prognostic value as ambulatory blood pressure monitoring, the availability of which is currently very limited. Moreover, ambulatory self-measurements have the significant benefit of being able to improve control of hypertensive individuals.Healthcare professionals and patients should be aware of the methodology of home blood pressure measurement, its usefulness and limitations. (AU)

El método utilizado habitualmente para el diagnóstico y seguimiento de los pacientes hipertensos ha sido la medida de la presión arterial en la consulta, pero es un hecho conocido que este método plantea problemas (sesgos del observador, no detecta reacción de alerta en consulta…) que afectan a su precisión como método diagnóstico.Las diferentes sociedades científicas internacionales, en los últimos años, recomiendan de forma insistente el uso de medidas de presión arterial fuera de la consulta (domiciliarias o ambulatorias) con aparatos automáticos validados para tomar decisiones. Datos de algunos estudios sugieren que si solo utilizamos las medidas de la consulta nos podemos equivocar en torno a un 15-20% de las veces que tomemos decisiones en el diagnóstico y seguimiento de los pacientes.Las medidas domiciliarias de presión arterial son un método sencillo y muy accesible que tienen una reproducibilidad y valor pronóstico similar al de las medidas ambulatorias, cuya disponibilidad actualmente e muy limitada, y que además tienen una utilidad importante que es la posibilidad de mejora del control de los hipertensos.Los profesionales sanitarios y los pacientes deben conocer la metodología de uso de la medida de presión arterial domiciliaria y sus utilidades y limitaciones. (AU)

Home blood pressure self-measurement: "Current situation and new perspectives".

The method typically used to diagnose and monitor hypertensive patients has been to measure blood pressure in the physician's surgery; however, it is a well-known fact that this approach poses certain drawbacks, such as observer bias, failure to detect an alert reaction in the clinic, etc., difficulties that affect its accuracy as a diagnostic method. In recent years, the varying international scientific societies have persistently recommended the use of blood pressure measurements outside the clinic (at home or in the outpatient setting), using validated automatic devices. Data from some studies suggest that if we rely solely on in-office measurements, approximately 15-20% of the time we may be wrong when making decisions, both in terms of diagnosis and patient follow-up. Home blood pressure measurements are a simple and very affordable method that has a similar reproducibility and prognostic value as ambulatory blood pressure monitoring, the availability of which is currently very limited. Moreover, ambulatory self-measurements have the significant benefit of being able to improve control of hypertensive individuals. Healthcare professionals and patients should be aware of the methodology of home blood pressure measurement, its usefulness and limitations.

Critical view of robotic-assisted transverse abdominal release (r-TAR).

INTRODUCTION: Establishing straightforward and reproducible steps to describe the technique performed with the aid of the robotic system for complex hernia surgery is key for good outcomes. Even using the description of open surgery as a parameter for performing the robotic technique, it is important to stress the particularities of this access. To describe the steps to perform robotic-assisted TAR (r-TAR) in a standardized technique, with a critical and safe view of all the anatomical structures. DESCRIPTION OF THE TECHNIQUE: We defined 8 landmarks for the critical view of safety in r-TAR which include: (1) patient position, trocar and docking; (2) posterior rectus sheath mobilization; (3) transversus abdominis release (TAR)-Top-down technique; (4) transversus abdominis release (TAR)-bottom-up technique and mesh insertion; (5) contralateral trocar insertion and redocking, 6) posterior sheath closure; (7) final mesh positioning; and (8) anterior defect closure and drains. DISCUSSION: Complex hernia surgery using a robotic-assisted posterior component separation requires well-established steps so the procedure can be reproducible and achieve better results.

Computed tomography imaging in ventral hernia repair: can we predict the need for myofascial release?

INTRODUCTION: Currently, the need for additional myofascial release (AMR) in addition to retromuscular dissection during open Rives-Stoppa hernia repair is determined intraoperatively based on the discretion of the surgeon. We developed a novel method to objectively predict the need for AMR preoperatively using computed tomography (CT)-measured rectus width to hernia width ratio (RDR). METHODS: A retrospective chart review of all patients who underwent open retro-muscular mesh repair of midline ventral hernia between August 1, 2007 and February 1, 2018, who had a preoperative CT scan within 1 year prior to their operation. The primary endpoint was the ability of the defect ratio to predict the need for AMR in pursuit of fascial closure. The secondary endpoint was the ability of Component Separation Index (CSI) to predict the need for AMR to obtain fascial closure. RESULTS: Of 342 patients, 208 repaired with rectus abdominis release alone (RM group), while 134 required AMR (RM + group). An RDR of > 1.34 on area under the curve analysis predicted the need for AMR with 77.6% accuracy. There was a linear decrease in the need for AMR with increasing RDR: RDR < 1 required AMR in 78.8% of cases, RDR 1.1-1.49 in 52%, RDR 1.5-1.99 in 32.1%, and RDR > 2 in just 10.8%. Similarly, CSI > 0.146 predicted the need for AMR with 76.3% accuracy on area under the curve analysis. CONCLUSION: The RDR is a practical and reliable tool to predict the ability to close the defect during open Rives-Stoppa ventral hernia repair without AMR. An RDR of > 2 portends fascial closure with rectus abdominis myofascial release alone in 90% of cases.

Prophylactic mesh augmentation using permanent synthetic mesh: outcomes of keyhole and Stapled Ostomy Reinforcement with Retromuscular Mesh techniques.

INTRODUCTION: Parastomal hernias (PSH) are the most common complication of stoma creation and can cause significant morbidity. We present a consecutive series of patients receiving prophylactic mesh augmentation (PMA) for prevention of PSH. METHODS: This retrospective review evaluates the efficacy and outcomes of PMA for PSH prevention, and retrospectively compares traditional keyhole PMA (tPMA) (n = 28) with a prophylactic Stapled Ostomy Reinforcement with Retromuscular Mesh technique (pSTORRM) (n = 24). RESULTS: PMA was performed in 52 cases between January 2015 and July 2018. All cases used a large-pore, non-coated, mid-weight polypropylene mesh placed in the retrorectus space. With a median follow-up of 16 mos, parastomal hernia was confirmed in 11.5% (n = 6), 5 of whom were symptomatic. patient-reported outcomes (PRO) indicated 6 additional patients with symptoms associated with PSH without clinical or radiographic confirmation. Patients had similar comorbidities and operative characteristics between tPMA and pSTORRM techniques, and no difference in a median follow-up. pSTORRM patients had fewer surgical site infections (8.3 vs 32.1%; p = 0.046) and occurrences (12.5 vs 46.4%; p = 0.015), and lower rate of PSH, though not statistically significant (4.2 vs 17.9%; p = 0.195). CONCLUSION: Permanent synthetic mesh placed as a sublay in the retromuscular space is safe and appears to decrease the risk of PSH formation after the creation of permanent stomas. A stapled technique may provide advantages over a traditional keyhole technique.

Primary thoracoabdominal hernias.

BACKGROUND: Primary thoracoabdominal hernias involve the triad of an intercostal hernia, abdominal wall hernia, and diaphragmatic hernia. We report a case series of this rare entity and describe the evolution and outcomes. METHODS: We completed a retrospective analysis of thoracoabdominal hernia repairs performed January 2010-April 2019 at Prisma Health-Upstate and Carolinas Medical Center. This includes all patients with spontaneous defects, excluding incisional hernias or those resulting from external trauma. RESULTS: Of 16 patients with thoracoabdominal hernias, 15 patients developed hernias after forceful coughing and one patient developed a hernia after strenuous physical activity. Seven patients required at least one additional intervention; two for recurrence; two for recurrence of original intercostal repairs done elsewhere; two for wound complications; and one had a missed abdominal wall component. CONCLUSIONS: Primary thoracoabdominal hernias require a high index of suspicion. Durable repair involves complex reconstruction of the thoracoabdominal wall including the diaphragm, intercostal space, rib fracture fixation, and mesh reinforcement of the abdominal wall with permanent fixation constructs.

Criteria for definition of a complex abdominal wall hernia.

PURPOSE: A clear definition of "complex (abdominal wall) hernia" is missing, though the term is often used. Practically all "complex hernia" literature is retrospective and lacks proper description of the population. There is need for clarification and classification to improve patient care and allow comparison of different surgical approaches. The aim of this study was to reach consensus on criteria used to define a patient with "complex" hernia. METHODS: Three consensus meetings were convened by surgeons with expertise in complex abdominal wall hernias, aimed at laying down criteria that can be used to define "complex hernia" patients, and to divide patients in severity classes. To aid discussion, literature review was performed to identify hernia classification systems, and to find evidence for patient and hernia variables that influence treatment and/or prognosis. RESULTS: Consensus was reached on 22 patient and hernia variables for "complex" hernia criteria inclusion which were grouped under four categories: "Size and location", "Contamination/soft tissue condition", "Patient history/risk factors", and "Clinical scenario". These variables were further divided in three patient severity classes ('Minor', 'Moderate', and 'Major') to provide guidance for peri-operative planning and measures, the risk of a complicated post-operative course, and the extent of financial costs associated with treatment of these hernia patients. CONCLUSION: Common criteria that can be used in defining and describing "complex" (abdominal wall) hernia patients have been identified and divided under four categories and three severity classes. Next step would be to create and validate treatment algorithms to guide the choice of surgical technique including mesh type for the various complex hernias.

Management of complications after laparoscopic Roux-en-Y gastric bypass.

Obesity has become an increasing problem in developed countries and laparoscopic Roux-en-Y gastric bypass (LRYGB) is one of the leading treatments for this disease. Although studies show that it is effective in reducing weight and lessening comorbidities, both early and late complications can occur. Early complications include venous thromboembolism, anastomotic leak, and hemorrhage. Late complications include obstruction, anastomotic stenosis, fistula, ulcer, cholelithiasis and nutritional deficiencies. Diagnosis of these complications is often challenging due to the lack of specificity of the presenting signs and symptoms. A high index of suspicion for detecting these complications is universally advocated. Fortunately, mortality from this procedure is rare. Management of the complications is generally consistent with basic surgical principles and surgical reinterventions can often be performed either endoscopically or laparoscopically depending on the situation and the surgeon's expertise. The available literature is confounded by mixing of results between open and laparoscopic techniques as well as the substantial differences in technique between authors reporting their outcomes. Although there is no consensus for managing the reported complications of LRYGB surgery, this article reviews the current literature and describes the presentation, diagnosis, and management of each of the early and late complications associated with the procedure.

Mesh terminology 101.

In any collaborative endeavor, when fields like medicine and bioengineering overlap, the proper use of technical vocabulary takes on added importance. It is important that scientists and clinicians, while coming from different backgrounds and educational systems, agree upon and utilize a common language based on mutually understood concepts and definitions. Regarding biomaterial testing applications, numerous terms are used to describe a wide variety of material behaviors when test specimens are subjected to mechanical, chemical, electrical and thermal stressors. In this discussion we will limit ourselves to the mechanical properties of materials which are utilized for soft tissue or fascial-based repairs. Following a literature search combining the keywords surgical mesh and biomaterials testing, common terms used to describe the mechanical properties of mesh were selected. Our analysis seeks to define the following terms and describe their applicability within the context of biomaterials for hernia repair: elasticity, stiffness, flexibility, tensile strength, distension, deformation, bending stiffness, and compliance. Unfortunately, in the technical literature, terms are often altered or extrapolated without adequate explanation. In other cases, related but technically different terms are mistakenly used interchangeably. With the mounting interest in biomaterials for the use in repair of abdominal wall defects, there is a need to standardize the terminology used to describe the biomechanical properties of mesh.

Bone anchor mesh fixation for complex laparoscopic ventral hernia repair.

BACKGROUND: Laparoscopic ventral hernia repair (LVHR) has gained wide acceptance by both surgeons and patients, but hernias that approach a bony prominence are more complex due to the difficulty of proper fixation. This study was conducted to evaluate the use of bone anchor mesh fixation for complex LVHR. METHODS: A prospective study of patients having complex LVHR with bone anchors was conducted using patients from 2 academic institutions between July 2003 and December 2007. Patient demographic data, characteristics of the hernia, operative details, and postoperative outcomes were recorded. RESULTS: A total of 30 patients who had LVHR using bone anchors were evaluated (20 women, 10 men; mean age 60.9 years, range 41-83 years). In all, 17 suprapubic and 13 lateral hernias were included, requiring a mean of 2.8 and 3.2 bone anchors, respectively. The average hernia defect was 263 cm(2) (range 35-690 cm(2)), and the average mesh size was 663 cm(2) (range 255-1360 cm(2)). Mean operative time was 218 minutes (range 98-420 minutes), with an estimated blood loss of 46 mL (range 10-100 mL). The average length of stay was 5.2 days (range 1-26 days). Seven patients (23.3%) developed postoperative complications, and 1 patient in this study died (mortality 3.3%). During follow-up of 13.2 months (range 1-26 months), 2 patients (6.7%) developed a recurrent hernia. CONCLUSIONS: Bone anchors can be used successfully in the laparoscopic repair of complex ventral hernias, particularly with suprapubic and lateral hernias that approach a bony prominence. The complication rate is acceptable, with a short hospital stay and low recurrence rate.

Interparietal hernias after open retromuscular hernia repair.

The retromuscular or sublay repair of ventral hernias, popularized by Rives and Stoppa, requires that a layer of tissue be reapproximated dorsal to the mesh to separate the bowel from the prosthetic. This is the first report of two patients who developed bowel obstruction resulting from interparietal incarceration between the posterior rectus sheath and the prosthetic graft through a defect in this dorsal layer. Both patients underwent open retromuscular hernia repair, one with lightweight polypropylene mesh, the other with human acellular dermal matrix. Postoperatively (day 3 and day 42, respectively), the patients developed signs of bowel obstruction. Computed tomography demonstrated the herniation of the small bowel into the potential space between the prosthesis and the posterior rectus sheath. The first patient underwent successful laparoscopic repair, while the second patient had an open operation to reduce the incarcerated bowel and repair the defect. In the patient convalescing from an uneventful retromuscular hernia repair who develops signs and symptoms of a bowel obstruction, there should be a high index of suspicion that an interparietal hernia may have formed, with the small bowel herniated into the surgically created space between the prosthetic and the posterior rectus sheath.

Posterior components separation during retromuscular hernia repair.

BACKGROUND: Retromuscular ventral hernia repair with mesh is a durable technique. In this paper, we describe a novel technique which allows for significant mesh overlap via the retromuscular space in cases of massive ventral hernia. METHODS: The retromuscular space is developed laterally, to the edge of the rectus sheath. The posterior rectus sheath is incised, dividing the posterior aponeurosis of the internal oblique. The dissection is carried out laterally between the internal oblique and the transversus abdominis muscle, creating space for a large mesh underlay. RESULTS: We have performed this technique successfully in 20 patients with a mean defect area of 223 cm(2) and a mean mesh area of 698 cm(2). Three patients developed wound complications and none complained of long-term pain or abdominal wall deformity. There has been one recurrence due to technical error after a mean 12-month follow-up. CONCLUSION: This technique of dissection between the internal oblique and transversus abdominis muscles allows for the closure of large hernia defects. The mechanism is two-fold: (1) mobility for closure of the posterior rectus sheath, dorsal to the prosthetic; and (2) increased mobility of the rectus, internal, and external obliques, allowing reconstruction of the linea alba.

Laparoscopic mesh hiatoplasty for paraesophageal hernias and fundoplications: a critical analysis of the available literature.

BACKGROUND: Little grade A medical evidence exists to support the use of prosthetic material for hiatal closure. Therefore, the authors compiled and analyzed all the available literature to determine whether the use of prosthetic mesh in hiatoplasty for routine laparoscopic fundoplications (LF) or for the repair of large (>5 cm) paraesophageal hernias (PEH) would decrease recurrence. METHODS: A literature search was performed using an inclusive list of relevant search terms via Medline/PubMed to identify papers (n = 19) describing the use of prosthetic material to repair the crura of patients undergoing laparoscopic PEH reduction, LF, or both. RESULTS: Case series (n = 5), retrospective reviews (n = 6), and prospective randomized (n = 4) and nonrandomized (n = 4) trials were identified. Laparoscopic procedures (n = 1,368) were performed for PEH, gastroesophageal reflux disease (GERD), hiatal hernia, or a combination of the three. Group A (n = 729) had primary suture repair of the crura, and group B (n = 639) had repair with either interposition of mesh to close the hiatus or onlay of prosthetic material after hiatal or crural closure. The use of mesh was associated with fewer recurrences than primary suture repair in both the LF and PEH groups. The mean follow-up period did not differ between the groups (20.7 months for group A vs. 19.2 months for group B). None of the papers cited any instance of prosthetic erosion into the gastrointestinal tract. CONCLUSIONS: The current data tend to support the use of prosthetic materials for hiatal repair in both routine LF and the repair of large PEHs. Longer and more stringent follow-up evaluation is necessary to delineate better the safety profile of mesh hiatoplasty. Future randomized trials are needed to confirm that mesh repair is superior to simple crural closure.

Multimedia article. Laparoscopic management of median arcuate ligament syndrome.

Median arcuate ligament syndrome is a rare disorder resulting from luminal narrowing of the celiac artery by the insertion of the diaphragmatic muscle fibers or fibrous bands of the celiac nervous plexus. The syndrome is characterized by weight loss, postprandial abdominal pain, nausea, vomiting, and an epigastric bruit. Surgical management entails complete division of the median arcuate ligament. The video demonstrates the laparoscopic release of the median arcuate ligament in a patient with median arcuate ligament syndrome. The patient is a 22-year-old male with a 6-month history of epigastric abdominal pain, nausea, vomiting, a 140-lb. weight loss, and an epigastric bruit on physical exam. Aortography demonstrated a >or=90% extrinsic compression of the celiac artery. A full laparoscopic skeletonization of the celiac artery and branch vessels was performed. Intraoperative duplex U/S demonstrated flow rate reduction after the median arcuate ligament release. A postoperative CT angiogram demonstrated no residual stenosis. The patient was discharged on postoperative day 3 and remained asymptomatic after 7 months of follow-up. Laparoscopic release of the median arcuate ligament is a novel approach to the management of celiac artery compression syndrome. The role of minimally invasive techniques to manage median arcuate ligament syndrome is evolving but they appear to be a safe alternative to open surgery.

Do patient or hospital demographics predict cholecystectomy outcomes? A nationwide study of 93,578 patients.

BACKGROUND: The purpose of this study was to examine the influence of patient and hospital demographics on cholecystectomy outcomes. METHODS: Year 2000 data from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample database was obtained for all patients undergoing inpatient cholecystectomy at 994 nationwide hospitals. Differences (p < 0.05) were determined using standard statistical methods. RESULTS: Of 93,578 cholecystectomies performed, 73.4% were performed laparoscopically. Length of hospital stay (LOS), charges, morbidity, and mortality were significantly less for laparoscopic cholecystectomy (LC). Increasing patient age was associated with increased LOS, charges, morbidity, mortality, and a decreased LC rate. Charges, LOS, morbidity, and mortality were highest for males with a lower LC rate than for females Mortality and LOS were higher, whereas morbidity was lower for African Americans than for whites. Hispanics had the shortest LOS, as well as the lowest morbidity and mortality rates. Laparoscopic cholecystectomy was performed more commonly for Hispanics than for whites or African Americans, with lower charges for whites. Medicare-insured patients incurred longer LOS as well as higher charges, morbidity, and mortality than Medicaid, private, and self-pay patients, and were the least likely to undergo LC. As median income decreases, LOS increases, and morbidity decreases with no mortality effect. Teaching hospitals had a longer LOS, higher charges, and mortality, and a lower LC rate, with no difference in morbidity, than nonteaching centers. As hospital size (number of beds) increased, LOS, and charges increased, with no difference in morbidity. Large hospitals had the highest mortality rates and the lowest incidence of LC. Urban hospitals had higher LOS and charges with a lower LC rate than rural hospitals. After control was used for all other covariates, increased age was a predictor of increased morbidity. Female gender, LC, and intraoperative cholangiogram all predicted decreased morbidity. Increased age, complications, and emergency surgery predicted increased mortality, with laparoscopy and intraoperative cholangiogram having protective effects. Patient income, insurance status, and race did not play a role in morbidity or mortality. Academic or teaching status of the hospital also did not influence patient outcomes. CONCLUSIONS: Patient and hospital demographics do affect the outcomes of patients undergoing inpatient cholecystectomy. Although male gender, African American race, Medicare-insured status, and large, urban hospitals are associated with less favorable cholecystectomy outcomes, only increased age predicts increased morbidity, whereas female gender, laparoscopy, and cholangiogram are protective. Increased age, complications, and emergency surgery predict mortality, with laparoscopy and intraoperative cholangiogram having protective effects.

A novel technique of lumbar hernia repair using bone anchor fixation.

Lumbar hernias are difficult to repair due to their proximity to bone and inadequate surrounding tissue to buttress the repair. We analyzed the outcome of patients undergoing a novel retromuscular lumbar hernia repair technique. The repair was performed in ten patients using a polypropylene or polytetrafluoroethylene mesh placed in an extraperitoneal, retromuscular position with at least 5 cm overlap of the hernia defect. The mesh was fixed with circumferential, transfascial, permanent sutures and inferiorly fixed to the iliac crest by suture bone anchors. Five hernias were recurrent, and five were incarcerated; seven were incisional hernias, and three were posttraumatic. Back and abdominal pain was the most common presenting symptom. Mean hernia size was 227 cm(2) (60-504) with a mesh size of 620 cm(2) (224-936). Mean operative time was 181 min (120-269), with a mean blood loss of 128 ml (50-200). Mean length of stay was 5.2 days (2-10), and morphine equivalent requirement was 200 mg (47-460). There were no postoperative complications or deaths. After a mean follow-up of 40 months (3-99) there have been no recurrences. Our sublay repair of lumbar hernias with permanent suture fixation is safe and to date has resulted in no recurrences. Suture bone anchors ensure secure fixation of the mesh to the iliac crest and may eliminate a common area of recurrence.

Cirrhosis is not a contraindication to laparoscopic surgery.

BACKGROUND: Cirrhosis of the liver contributes significantly to morbidity and mortality in abdominal surgery. The proven benefits of laparoscopy seem especially applicable to patients with this complex disease. This study evaluates the safety and efficacy of laparoscopic procedures in a series of consecutively treated patients with biopsy-proven cirrhosis. METHODS: The medical records of all patients with biopsy-proven cirrhosis undergoing laparoscopic surgery at the authors' medical center between January 2000 and December 2003 were retrospectively reviewed. RESULTS: A total of 50 patients (27 men and 23 women) underwent 52 laparoscopic procedures. Among these 50 patients were 39 patients with Child-Pugh classification A cirrhosis, 10 with classification B, and 1 with classification C, who underwent a variety of laparoscopic procedures including cholecystectomy (n = 22), splenectomy (n = 18), colectomy (n = 4), diagnostic laparoscopy (n = 3), ventral hernia repair (n = 1), Nissen fundoplication (n = 1), Heller myotomy (n = 1), Roux-en-Y gastric bypass (n = 1), and radical nephrectomy (n = 1). There were two conversions (4%) to an open procedure. The mean operative time was 155 min. Estimated blood loss averaged 124 ml for all procedures, and 20 patients (40%) required perioperative transfusion of blood products. One patient required a single blood transfusion postoperatively because of anemia. No one experienced hepatic decompensation. Overall morbidity was 16%. There were no deaths. The mean length of hospitalization was 3 days. CONCLUSIONS: Although technically challenging because portal hypertension, varices, and thrombocytopenia frequently coexist, basic and advanced laparoscopic procedures are safe for patients with mild to moderate cirrhosis of the liver.

The susceptibility of prosthetic biomaterials to infection.

BACKGROUND: Despite the use of a sterile technique and the administration of prophylactic antibiotics during surgical procedures, mesh infection continues to complicate the use of biomaterials. The purpose of this study was to compare the susceptibility to infection of prosthetic biomaterials in a live-animal model. METHODS: The following seven prosthetic mesh biomaterials were used in this study. Expanded polytetrafluoroethylene (ePTFE) with silver/chlorhexidine (DM+), ePTFE (DM), porcine intestinal submucosa (S), polypropylene (M), ePTFE/polypropylene (X), hyaluronate/carboxymethylcellulose/polypropylene (SM), and human acellular dermal matrix (A). Lewis rats (n = 108) underwent creation of a single ventral hernia; 105 of them were repaired with a different mesh (2-cm2 piece). Twelve pieces of each mesh were inoculated at the time of hernia repair with 10(8) Staphylococcus aureus (n = 84). Three pieces of each mesh were placed without bacterial inoculation (n = 21). In three animals, no mesh was placed; instead, the peritoneum of the hernia defect was inoculated (n = 3). After 5 days, the animals were killed and the mesh was explanted (peritoneum for the nonmesh control). The mesh was vortex-washed and incubated in tryptic soy broth. Bacterial counts were determined using serial dilutions and spot plates and quantified in colony-forming units (CFU) per square centimeter of mesh present in the vortex wash fluid (wash count) and the soy broth (broth count). Data are presented as the mean log(10), with analysis of variance (ANOVA) and Tukey's test used to determine significance (p < 0.05). RESULTS: The DM+ material had no detectable live bacteria in the wash or broth counts in 10 of 12 tested samples (p = 0.05). Of the samples that showed bacterial growth, the peritoneum control group had a lower wash count than A (p = 0.05) and the lowest broth count of all the materials except for DM+ (p = 0.05). In addition, SM had a significantly lower wash count than A (p = 0.05), with no broth count difference. In regard to wash and broth counts, DM, M, X, SM, S, and A were no different (p = NS). CONCLUSIONS: The DM+ material was the least susceptible to infection. Impregnation with silver/chlorhexidine killed the inoculated bacteria, preventing their proliferation on the mesh surface. Other than DM+, native peritoneal tissue appears to be the least susceptible to infection. Silver/chlorhexidine appears to be an effective bactericidal agent for use with mesh biomaterials.