Surgical site infection after groin hernia repair

Antimicrobial prophylaxis in clean surgery with special focus on inguinal hernia repair with mesh

Until recently, antimicrobial prophylaxis was thought to be unnecessary for clean surgery except when a foreign body is implanted or the presence of infection poses a significant risk to patients. However, the results of several trials support extending the administration of antimicrobial prophylaxis to other types of clean surgery such as inguinal hernia repair or breast surgery. A recent Cochrane meta-analysis concluded that antimicrobial prophylaxis for inguinal hernia repair with or without mesh cannot be recommended or discarded. Resolution of this problem is important because inguinal hernia repair with mesh is one of the most common procedures in general surgery, and antibiotic consumption for preventive purposes is becoming a serious problem due to the risk of contribution to development of bacterial resistance and the significant increase in healthcare costs. This review will document clinical trials and meta-analyses on clean surgery, and will focus on inguinal hernia repair with mesh.

Inguinal hernia repair: are ASA grades 3 and 4 patients suitable for day case hernia repair?

The American Society of Anaesthesiologists (ASA) 3 and 4 patients are generally considered unsuitable for day case hernia repair. There are minimal data regarding the acceptability of day case repair in these patients. This study analysed day case hernia rates with special emphasis on ASA grades. A retrospective review of all adult inguinal hernia repairs, under the care of one surgeon over a 9-year period, was performed. The data collected included demographics, ASA grades, the mode of anaesthesia and early complications. 577 patients underwent inguinal hernia repair during the study period. 204 (35%) patients were ASA grade 1, 214 (37%) ASA grade 2, 132 (23%) ASA grade 3 and 29 (5%) ASA grade 4. Day case rates for ASA grades 1-4 under LA were 86, 83, 77 and 76% and under GA, 59, 36, 32 and 0%, respectively (P<0.05). There was no significant difference in the wound complication rates for different ASA grades under GA and LA. ASA grades 3 and 4 patients can undergo day case inguinal hernia repair, with similar complication rates to ASA grades 1 and 2 patients, when surgery is performed under local anaesthesia. ASA grades 3 and 4 patients need not be excluded from day case hernia repair.

Reduction in wound infection rates by wound surveillance with postdischarge follow-up and feedback

Background

Surgical wound surveillance with postdischarge follow-up is rarely done in the UK as it is seen as expensive. The aim of this study was to determine whether employing a dedicated team was effective and reduced costs.

Methods

Infection data were collected prospectively with postdischarge follow-up at 2–3 months, and fed back to surgeons. Wound infection was defined using both ASEPSIS wound scoring and criteria of the US Centers for Disease Control (CDC) definitions.

Results

Over 4 years, 15 548 patient episodes were included. Postdischarge surveillance data were available for 79·9 per cent of the 15 154 records of patients who survived. There was a significant reduction in the rate of wound infection between the first and fourth years by ASEPSIS and CDC definitions: odds ratio 0·77 (95 per cent confidence interval (c.i.) 0·64 to 0·92) and 0·69 (95 per cent c.i. 0·57 to 0·83), respectively. The proportion of infections fell significantly in orthopaedic, cardiac and thoracic surgery. The annual budget for wound surveillance was £91 600. Changes in infection rates contributed £347 491 to the reduction in cost among the patients surveyed.

Conclusion

Wound surveillance was associated with a reduction in rates of wound infection within 4 years. The cost reduction as a result of fewer infections exceeded the cost of surveillance after 2 years.

Use of Resterilized Polypropylene Mesh in Inguinal Hernia Repair: A Prospective, Randomized Study

BACKGROUND

Inguinal hernia repair consumes considerable health-care resources worldwide. Open mesh repairs are commonly used and the feasibility of using a resterilized mesh, which is a general practice in certain countries, has not been evaluated.

STUDY DESIGN

In this randomized prospective study, original and resterilized meshes were used in two groups of patients with unilateral inguinal hernia. Microbiologic changes, textile mechanical properties, overall complication rates, and cost-effectiveness of resterilized mesh were investigated. A time period of 3 years was determined for patient enrollment to this pilot feasibility study, with the goal of 100 patients in each group.

RESULTS

Ninety-one patients were enrolled in the original group and 93 in the resterilized mesh group. Median followup was 735 and 739 days and calculated interquartile ranges were 454 and 513 days, respectively. Average tensile strength of the original polypropylene mesh changed slightly with resterilization, as maximum load decreased from a mean of 66.6 to 58.2 N/cm. Overall complication rates were similar in the two groups. The 6.6% infection rate in the original mesh group was not statistically different from the 7.5% rate in the resterilized group (p = 0.80, relative risk = 0.88, 95% confidence interval, 0.31-2.51). There was only one recurrence in the original mesh group in the 21st month. Use of a resterilized mesh decreased the overall cost of operation by decreasing the cost of mesh from 15.9% to 8.3% of the total amount.

CONCLUSIONS

Use of a resterilized mesh for inguinal hernia repair is feasible without considerable changes in infection and recurrence rates.

Fate of the inguinal hernia following removal of infected prosthetic mesh

Open tension-free hernioplasty using a prosthetic mesh is a common operation for inguinal hernia repair because of the relative ease of the operation and low recurrence rate. Wound infection is a potential complication of all hernia repairs and deep-seated infection involving an inserted mesh may result in chronic groin sepsis which usually necessitates complete removal of mesh to produce resolution. Removal of mesh would potentially result in a weakness of the repair and subsequent hernia recurrence. We reviewed the outcome of all our patients who had mesh removal for sepsis over an 8-year period, particularly examining for hernia recurrence and chronic groin pain. This was a retrospective review of the database of patients who had mesh repair of inguinal hernias over an 8-year period. There were 2,139 inguinal hernias repaired using prosthetic mesh. All patients who had mesh removal for infection were identified and followed up. Fourteen patients had deep-seated wound infection which required mesh removal for resolution of sepsis. No peri-operative complications occurred during mesh removal. After a median follow-up of 44 months (range 5-91 months), there were two asymptomatic recurrences and none of the patients had chronic groin pain. Hernia recurrence is uncommon following mesh removal for chronic groin sepsis, suggesting that the strength of a mesh repair lies in the fibrous reaction evoked within the transversalis fascia by the prosthetic material rather than in the physical presence of the mesh itself. When there is established deep infection, there should be no unnecessary delay in removing an infected mesh in order to allow resolution of chronic groin sepsis.

Influence of statins on postoperative wound complications after inguinal or ventral herniorrhaphy

The lipid-lowering agents, statins, are the most commonly prescribed class of drugs in the western world. Because of their widespread use, many patients undergo surgical procedures while on statins. Statins, in addition to cholesterol-lowering effects, also have anticoagulant, immunosuppressive, and antiproliferative properties that may affect the risk of local wound complications. This study investigated the relationship between statins and postoperative wound complications in a large cohort of patients undergoing inguinal or ventral hernia repair. Data mining was performed in the Veterans Integrated Service Network (VISN)16 Data Warehouse. This database contains clinical and demographic information about all veterans cared for at the ten VA Medical Centers that comprise the South Central VA Healthcare Network in the mid-south region of the US. Aggregate data (age, body mass index, smoking history, gender, race, history of diabetes, statin use, and postoperative wound complications) were obtained for all patients who underwent inguinal or ventral hernia repair during the period October 1, 1996-November 30, 2004. During the period of the query, 10,782 patients (10,676 male, 106 female), 1,242 (11.5%) of whom received statins, underwent herniorrhaphy. Statin use did not affect the risk of wound infection or delayed wound healing. Statin use was, however, associated with an increased rate of local postoperative bleeding complications (P=0.01). When the type of hernia, age, smoking, diabetes, and body mass index were included in a multivariate analysis, statins remained borderline significant as an independent predictor of wound hematoma/postoperative bleeding (P=0.04), odds ratio 1.6 (95% CI 1.03-2.44). Patients who undergo inguinal herniorrhaphy while on statins have an increased risk of postoperative wound hematoma/hemorrhage. Focus on additional factors that may affect the propensity to postoperative bleeding and on meticulous intraoperative hemostasis are particularly important in such patients.

A study of telephone screening and direct observation of surgical wound infections after discharge from hospital

Post-discharge surveillance of surgical site infection is necessary if accurate rates of infection following surgery are to be available. We undertook a prospective study of 376 knee and hip replacements in 366 patients in order to estimate the rate of orthopaedic surgical site infection in the community. The inpatient infection was 3.1% and the post-discharge infection rate was 2.1%. We concluded that the use of telephone interviews of patients to identify the group at highest risk of having a surgical site infection (those who think they have an infection) with rapid follow-up by a professional trained to diagnose infection according to agreed criteria is an effective method of identifying infection after discharge from hospital.

Current strategies for prevention of surgical site infections

Surgical site infections (SSIs) are a common complication that follows all types of operative procedures. These infections are usually caused by the exogenous and endogenous microorganisms that enter the operative wound during the course of surgery. The general and procedure-specific risk factors for the development of SSI have been identified and are discussed in this article. Factors that influence the SSI rate and the current strategies for prevention of SSIs are also presented. Emphasis is placed on the efficacious use of antibiotic prophylaxis in surgery. A discussion of the principles of antibiotic prophylaxis, including choice of agents, route of administration, and timing, is offered. It appears that the use of less invasive laparoscopic surgical approaches, as practiced widely today, will be associated with an overall decreased incidence of SSI.