Treatment of mediastinitis: early modified Robicsek closure and pectoralis major advancement flaps

Changes of the Serum Antibiotic Levels During Open Heart Surgery (ceftazidim, ciprofloxacin, clindamycin)

Background: Wound, mediastinal and intracardiac infections are still very serious complications of open-heart surgey. The incidence of it is still in the range of 0.4%-5%. The aims of our study were to assess the adequacy of regimen using ceftazidim (CTZ), ciprofloxacin (CPF) and clindamycin (CLIN) as prophylactic antibiotics and to verify whether cardiopulmonary bypass (CPB) can modify the time of antibiotic serum concentrations. That is why the serum levels of them were measured during open heart procedures. Methods: The prospective study comprised 75 consequent coronary patients randomized in to three groups receiving 1 g of CTZ or 400 mg of CPF or 900 mg of CLIN i.v. with anesthesia induction. Routine coronary surgery with left internal mammary artery harvesting, moderate body hypothermic (30 °C) CPB with crystaloid cardioplegia was performed. Serum antibiotic levels were determined before application, with skin incision, prior CPB induction, after cardioplegia infusion, every 20 minutes of CPB, prior end of CPB, in time of chest closure. Conventional cylinder – plate microbiological assay was used for antibiotic levelmeasurement. Results: All serum antibiotic concentrations showed a sharp decrease immediately after starting CPB and lasted until CPB ended. After initiating of CPB after cardioplegia administration serum concentrations of CTZ (105 min after initial dose) decreased by, on average 55%, CPF (97 min) by 42% and CLIN (116 min) by 78%. Conclusion: CPB can modify the time course of antibiotic serum concentrations. The serum levels of CTZ at the end of the longest procedures were found to be below the MICs for some of the suspected pathogens. We recommend to use higher antibiotic doses for prophylaxis and to administer the second dose with protamin sulphate to obtain maximum concentration in newly formed blood clots.

The 'Two Bridges Technique' for sternal wound closure. The use of vacuum-assisted closure for the treatment of deep sternal wound defects: a centre-specific technique

The objective is to describe the 'Two Bridges Technique' (TBT), which has proven to be successful and has been the standard technique at our centre for vacuum-assisted closure (VAC) of post-sternotomy mediastinitis. An extensive literature search was performed in four databases to identify all published articles concerning VAC for post-sternotomy mediastinitis. Several VAC methods have been used; however, no article has described our specific technique. TBT consists of a two-bridges construction using two types of foam with different pore sizes, which ensures an equally divided negative pressure over the wound bed and stabilisation of the chest. This guarantees a continuous treatment of the sternal defect and prevents foam displacement. It maintains an airtight seal that prevents skin maceration and provides enough protection to avoid right ventricular rupture. The main advantage of TBT is the prevention of shifting or tilting of the foam during chest movements such as breathing or couching. Along with targeted antibiotic treatment, this alternative VAC technique can be an asset in the sometimes cumbersome treatment of post-sternotomy mediastinitis.

Therapeutic Outcomes of Pectoralis Major Muscle Turnover Flap in Mediastinitis

Background

This study aimed to evaluate the therapeutic results and safety of pectoralis major muscle turnover flaps in the treatment of mediastinitis after coronary artery bypass grafting (CABG) procedures.

Methods

Data regarding 33 patients with post-CABG deep sternal wound infections (DSWIs) who underwent pectoralis major muscle turnover flap procedures in the Emam Reza and Ghaem Hospitals of Mashhad, Iran were reviewed in this study. For each patient, age, sex, hospital stay duration, remission, recurrence, and associated morbidity and mortality were evaluated.

Results

Of the 2,447 CABG procedures that were carried out during the time period encompassed by our study, DSWIs occurred in 61 patients (2.5%). Of these 61 patients, 33 patients (nine females [27.3%] and 24 males [72.7%]) with an average age of 63±4.54 years underwent pectoralis major muscle turnover flap placement. Symptoms of infection mainly occurred within the first 10 days after surgery (mean, 10.24±13.62 days). The most common risk factor for DSWIs was obesity (n=16, 48.4%) followed by diabetes mellitus (n=13, 39.4%). Bilateral and unilateral pectoralis major muscle turnover flaps were performed in 20 patients (60.6%) and 13 patients (39.4%), respectively. Complete remission was achieved in 25 patients (75.7%), with no recurrence in the follow-up period. Four patients (12.1%) needed reoperation. The mean hospitalization time was 11.69±6.516 days. Four patients (12.1%) died during the course of the study: three due to the postoperative complication of respiratory failure and one due to pulmonary thromboembolism.

Conclusion

Pectoralis major muscle turnover flaps are an optimal technique in the treatment of post-CABG mediastinitis. In addition to leading to favorable therapeutic results, this flap is associated with minimal morbidity and mortality, as well as a short hospitalization time.

Assessment of vacuum-assisted closure therapy on the wound healing process in cardiac surgery

Postoperative deep sternal wound infection (DSWI) is a serious complication in cardiac surgery (1-5% of patients) with high mortality and morbidity rates. Vacuum-assisted closure (VAC) therapy has shown promising results in terms of wound healing process, postoperative hospital length of stay and lower in-hospital costs. The aim of our retrospective study is to report the outcome of patients with DSWI treated with VAC therapy and to assess the effect of contributory risk factors. Data of 52 patients who have been treated with VAC therapy in a single institution (study period: September 2003-March 2012) were collected electronically through PAtient Tracking System PATS and statistically analysed using SPSS version 20. Of the 52 patients (35 M: 17 F), 88·5% (n = 46) were solely treated with VAC therapy and 11·5% (n = 6) had additional plastic surgical intervention. Follow-up was complete (mean 33·8 months) with an overall mortality rate of 26·9% (n = 14) of whom 50% (n = 7) died in hospital. No death was related to VAC complications. Patient outcomes were affected by pre-operative, intra-operative and postoperative risk factors. Logistic EUROscore, postoperative hospital length of stay, advanced age, chronic obstructive pulmonary disease (COPD) and long-term corticosteroid treatment appear to be significant contributing factors in the long-term survival of patients treated with VAC therapy.

Sternal force distribution during median sternotomy retraction

BACKGROUND

Median sternotomy is the access of choice in cardiac surgery. Sternal retractors exert significant forces on the thoracic cage and might cause considerable damage. The aim of this study was to determine the effects of retractor shape on local force distribution to obtain criteria for retractor design.

METHODS

Two types of sternal retractors (straight [SSR] and curved [CSR]) were equipped with force sensors. Force distribution, total force, and displacement were recorded to a spread width of 10 cm in 18 corpses (11 males and 7 females; age, 62 ± 12 years). Both retractors were used in alternating sequence in 4 iterations in every corpse. Data were compared with respect to the different retractor blade shapes.

RESULTS

Maximum total forces for full retraction of both retractors resulted in 349.4 ± 77.9 N. Force distribution during the first retraction for the cranial/median/caudal part of the sternum was 101.5 ± 43.9/29.1 ± 33.9/63.0 ± 31.4 N for the SSR and 38.7 ± 41.3/80.9 ± 64.5/34.0 ± 25.8 N for the CSR, respectively. During the 4 spreading cycles, the average force decreased from 224.6 ± 61.3 N in the first to 110.8 ± 39.8 N in the fourth iteration. The mean total force for the first retraction revealed 226.4 ± 71.9 N for the CSR and 222.8 ± 52.9 N for the SSR.

CONCLUSIONS

The shape of sternal retractors considerably influences the force distribution on the sternal incision. In the SSR, forces on the cranial and caudal sternum are significantly higher than in the median section, whereas in the CSR, forces in the median section are highest.

Management of sternal precautions following median sternotomy by physical therapists in Australia: a web-based survey

BACKGROUND

Sternal precautions are utilized within many hospitals with the aim of preventing the occurrence of sternal complications (eg, infection, wound breakdown) following midline sternotomy. The evidence base for sternal precaution protocols, however, has been questioned due to a paucity of research, unknown effect on patient outcomes, and possible discrepancies in pattern of use among institutions.

OBJECTIVE

The objective of this study was to investigate and document the use of sternal precautions by physical therapists in the treatment of patients following median sternotomy in hospitals throughout Australia, from immediately postsurgery to discharge from the hospital.

DESIGN

A cross-sectional, observational design was used. An anonymous, Web-based survey was custom designed for use in the study.

METHODS

The questionnaire was content validated, and the online functionality was assessed. The senior cardiothoracic physical therapist from each hospital identified as currently performing cardiothoracic surgery (N=51) was invited to participate.

RESULTS

The response rate was 58.8% (n=30). Both public (n=18) and private (n=12) hospitals in all states of Australia were represented. Management protocols reported by participants included wound support (n=22), restrictions on lifting and transfers (n=23), and restrictions on mobility aid use (n=15). Factors influencing clinical practice most commonly included "workplace practices/protocols" (n=27) and "clinical experience" (n=22). Limitations The study may be limited by response bias.

CONCLUSIONS

Significant variation exists in the sternal precautions and protocols used in the treatment of patients following median sternotomy in Australian hospitals. Further research is needed to investigate whether the restrictions and precautions used are necessary and whether protocols have an impact on patient outcomes, including rates of recovery and length of stay.

Transthoracic approach for liver tumors

Abdominal approach is commonly used for resection of liver tumors. However, in rare cases, transthoracic approach may be a valuable option for management of lesions located in the hepatic dome or involving the cavo-hepatic junction for very selected patients. This approach can be an open procedure (thoracotomomy), a video-assisted minimally invasive technique (thoracoscopy), or a strictly percutaneously treatment (CT-guided radiofrequency ablation). This approach seems useful for high-risk patients, with previous major abdominal surgery, or awaiting for liver transplantation (bridge concept) with cranially located single lesions. A limited liver resection (tumorectomy or segmentectomy) can be performed, but this approach is also suitable for percutaneous ablation therapy (radiofrequency or cryotherapy), with an acceptable morbidity.

Figure-of-eight versus prophylactic sternal weave closure of median sternotomy in diabetic obese patients undergoing coronary artery bypass grafting

BACKGROUND

Sternal dehiscence is a serious and potentially devastating complication after median sternotomy, especially in diabetic obese patients. The optimal technique for sternal closure is unclear in these patients.

METHODS

The purpose of this prospective randomized study was to compare the incidence of sternal dehiscence after prophylactic sternal weave and figure-of-eight suturing in diabetic obese patients undergoing coronary artery bypass grafting (CABG). The patients were randomly assigned to group A (figure-of-eight closure; n=75) or group B (sternal weave closure; n=75).

RESULTS

There were 8 cases of sternal dehiscence documented: 7 in group A and 1 in group B. In group A, 5 patients had noninfectious sternal dehiscence and 2 patients underwent reoperation because of sternal dehiscence with mediastinitis. Also, 1 of the noninfected patients had deep-seated pain with a feeling of bony crepitus and needed reoperation. The other 4 patients in group A and 1 patient with noninfectious sternal dehiscence in group B were given chest binder support. Pain and bony crepitus decreased in the follow-up period of 1 year. Sternal dehiscence rates were 9.3% in group A and 1.3% in group B. Sternal dehiscence was significantly lower in group B (p<0.05).

CONCLUSIONS

Prophylactic sternal weave closure of median sternotomy reduces morbidity from sternal dehiscence in diabetic obese patients undergoing CABG.

Functional impairment after treatment with pectoral muscle flaps because of deep sternal wound infection

OBJECTIVE

Pectoral muscle flaps (PMF) are effective in terminating protracted sternal wound infections (SWI) but long-term outcome remains uncertain. Therefore, the aim of this study was to evaluate long-term outcome in patients treated with PMF.

DESIGN

Thirty-four of 263 patients revised because of deep SWI from 1991--2005 were treated with PMF. Of the 21 patients alive, 11 had left-sided, two right-sided and eight bilateral procedures. Sternal debridement without closure of the sternum was done in 17 patients. Nineteen of 21 patients responded to a questionnaire.

RESULTS

At follow-up on average 5.9 years (range 1.9--14.8 years) after surgery 63% (12/19) experienced unstable chest. Two thirds (12/18) reported problems carrying a grocery bag and 37% (7/19) had problems putting on a coat. Reduction of power and mobility was more common in the right arm and shoulder even in patients with left-sided PMF. Thirty-two percent (6/19) would have preferred alternative treatment if possible to avoid sternal instability even if healing had been substantially delayed.

CONCLUSIONS

Surgery with PMF and sternal debridement was associated with long-term disability, which appeared to be significant in one third of the patients. The function of the right arm and shoulder was affected more often despite the majority of procedures being left-sided suggesting that loss of skeletal continuity of the chest wall is more disabling than loss of pectoral muscle function.

[Myoplasty by reversal of the pectoris major muscle in the treatment of mediastinitis. A case report and review of the literature]

Mediastinitis are among the most dreadful infectious complications following cardiac surgery. Their prognosis depends essentially on the precociousness of the diagnosis. In most of the cases, the medical treatment associated with an irrigation drainage is sufficient. But in case of severe sternal dehiscence, plastic surgery becomes necessary in order to fill up the loss with a well-vascularized tissue. We report the case of a 78-year-old patient, chronic bronchitic who presented, after a coronary artery bypass, an aseptic sternal dehiscence necessitating an osteosynthesis, then a Klebsiella pneumoniae mediastinitis with an enlarged sternal necrosis which was treated by bone resection and a myoplasty via reversal of the right pectoris major muscle. The postsurgery course was favourable. Now, after one-year remote, cicatrisation is complete and we have not noticed any infectious recurrence.

Figure-of-Eight vs. Interrupted Sternal Wire Closure of Median Sternotomy

Sternal dehiscence is a rare but devastating complication following median sternotomy for cardiac surgery. The optimal technique for sternal closure is unclear. We conducted this prospective randomized trial to compare the incidence of sternal dehiscence after figure-of-8 and simple interrupted suturing in patients undergoing coronary artery bypass grafting. Between January 2007 and June 2008, 98 patients had figure-of-8 suturing and 97 had interrupted sutures. The mean age of the patients was 60.9 ± 7.6 years. The overall sternal dehiscence rate was 8%; 7 cases in the in figure-of-8 group and 9 in the interrupted group. Thirteen patients had no wound infection and healed with conservative treatment. Only 3 patients had sternal dehiscence with infection: 2 with simple interrupted closure and 1 with figure-of-8 sternal closure. There was no significant difference in rates of sternal dehiscence between the 2 groups. It was concluded that figure-of-8 sternal suturing is equally effective as simple interrupted suturing in preventing sternal dehiscence.

Patients with sternal wound infection after cardiac surgery do not improve their quality of life

OBJECTIVES

Sternal wound infection after cardiac operations leave physical, cosmetic and mental scar i.e. low quality of life (QoL). To better understand and evaluate health related to QoL we used SF-36 and also analysed if there were any different outcome in SWI subgroups due to different surgical techniques.

DESIGN

Between January 1, 1998 and June 30, 2002 a total of 97 patients developed SWI at our department. The patients were followed up in terms of survival by computerised linkage to a continuously updated population register. On January 1, 2003, 84 patients could be identified as being alive and constituted the study group (SWI group) and compared with 42 patients prior to coronary artery bypass grafting (CABG) and evaluated one year postoperative (CABG group), and matched for time of the operation, age and sex.

RESULTS

The median follow-up time after cardiac surgery was 20 months (range 7-40). Late mortality was 13.4% (13/97 patients) with the median time of 5 months (range 0.5-26) postoperative. The response rate was 86.9% and SF-36 showed that SWI patients deviated significantly from the normative data for the general Swedish population. QoL for the SWI patients was comparable to QoL assessed prior to cardiac surgery i.e. the CABG group. The different surgical techniques used were comparable as they did not affect the outcome of QoL.

CONCLUSIONS

Our results confirm that if the patients survive, SWI is a very serious complication concerning QoL. At follow up the SWI patients did not improve their QoL, with no difference in surgical technique used, although they had undergone open heart surgery.

Our experience using the vertical rectus abdominis muscle flap for reconstruction in 12 patients with dehiscence of a median sternotomy wound and mediastinitis

The vertical rectus abdominis (VRAM) flap has been used for reconstruction of sternal defects, particularly in the inferior third, since it was first described 20 years ago. We describe 12 patients with mediastinitis or chronic sternal osteomyelitis after sternotomy treated between 1994 and 1997, nine performed at the Royal Hospitals Trust, London. Sternal osteomyelitis and mediastinitis after median sternotomy is an uncommon (0.4%-8.4%) but often fatal condition. Vascularised pedicles are the treatment of choice, and VRAM flaps were used in all cases. We report good long-term outcome with a follow up of 2-5 years, and no long-term morbidity relating to the VRAM reconstruction. We had only one partial failure of a flap. The operations were largely done in hospitals away from the plastic surgical unit in extremely sick patients, which illustrates the importance of multidisciplinary management to reduce hospital stay, mortality, and morbidity. We argue that early involvement of plastic surgical specialists in the treatment of sternal dehiscence is essential to ensure a successful outcome.

Sternal stabilization by interlocking wires: an alternative simple technique for high-risk patients

BACKGROUND

Sternal dehiscence following midline sternotomy is associated with significant morbidity and mortality in high-risk patients.

METHODS

A novel simple technique of sternal stabilization after midline sternotomy by interlocking wires was introduced in high-risk patients with morbid obesity, diabetes, osteoporosis, chronic obstructive pulmonary disease, bilateral internal thoracic artery harvesting, or various combinations of the above.

RESULTS

A sternal stabilization by interlocking wires was performed in 25 consecutive high-risk patients. Stable sternum was achieved in all patients despite multiple risk factors.

CONCLUSION

We describe a simple technique of interlocking wires that provides excellent stabilization of the sternum after midline stenotomy in high-risk patients. This technique utilizes the benefit of figure-eight wires, provides the continuity of the weave and effectively prevents cutting of the wires through the sternum without compromising its blood supply.

Risk factors for mortality in patients with mediastinitis after cardiac surgery

BACKGROUND

Patients with mediastinitis after cardiac surgery have higher morbidity and mortality.

AIMS

Describe the characteristics of patients with mediastinitis, determine the mortality within one month, and assess the risk factors associated with mortality.

METHODS

Retrospective cohort study including all adult patients with mediastinitis during the 2002-2006 period at the Nantes University Hospital. Multivariate analysis by logistic regression and Kaplan-Meier curve of survey were done.

RESULTS

Nearly 5574 patients were operated during the study period, with a mediastinitis incidence rate of 0.7%, 28 patients (72%) had coronary artery bypass graft. The mortality rate increased from de 12.8% during hospital stay to 20.5% within one year. Only two deaths were associated with mediastinitis. The occurrence of a co-infection was the only independent risk factor associated with mortality (OR 13, P<0.04). The instantaneous risk of death was increased by 7 in patient with co-infection, particularly mechanical ventilator-associated pneumonia (CR 1,97).

CONCLUSION

Mortality varied according to the duration of surveillance, and mediastinitis was not the major cause of death. Mechanical ventilator-associated pneumonia after mediastinitis increases the mortality and needs specific prevention.

Control of separation in sternal instability by supportive devices: a comparison of an adjustable fastening brace, compression garment, and sports tape

OBJECTIVE

To evaluate the effectiveness of 3 supportive devices in controlling sternal separation.

DESIGN

A cross-sectional, randomized intervention study.

SETTING

Participants were from the general community who were referred to the study by their cardiac surgeon or cardiologist.

PARTICIPANTS

Fifteen patients (12 men, 3 women) between 49 and 80 years of age with sternal instability after a median sternotomy.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Support from sports tape, a compression garment, and an adjustable fastening brace was assessed by an ultrasound-based measure of sternal separation contingent on movement and by self-report measures of comfort, pain, feeling of support, ease of upper-limb movement, and ease of breathing.

RESULTS

For both sternal separation and self-report data, some support was better than no support, and a supportive device worn on the body was better than sports tape. Wearing an adjustable fastening brace was better than a compression garment and, compared with no support, closed the sternal gap by 20% or 2.7 mm (95% confidence interval, 1.5-3.9 mm). The effects of wearing the different supportive devices on visual analog scale ratings of comfort, pain, support, ease of breathing, and movement mirrored the results obtained for sternal separation, thus providing agreement between self-report and objective measures.

CONCLUSIONS

Supportive devices may be useful in the management of patients with sternal instability because wearing one resulted in a reduction of both sternal separation and pain report after movement. The largest effect was obtained from wearing an adjustable fastening brace.

Experience with Vacuum-assisted closure of sternal wound infections following cardiac surgery and evaluation of chronic complications associated with its use

OBJECTIVES

We report our experience in use of Vacuum-assisted closure therapy (VAC) in the treatment of poststernotomy wound infection with emphasis on recurrent wound-related problems after use of VAC and their treatment.

METHODS

Between July 2000 and June 2003, 2706 patients underwent various cardiac procedures via median sternotomy. Forty-nine patients with postoperative sternal wound infection (1.9%) were managed with VAC. Wounds were classified as either superficial sternal wound infection (28 patients) or deep sternal wound infection (21 patients). In the superficial sternal wound infection group, 23 patients had VAC as definitive treatment (GroupA), while five patients (Group B) had VAC followed by surgical closure. Similarly, in the deep sternal wound infection group, 12 patients had VAC as definitive treatment (Group C), while nine patients had VAC followed by surgical closure (Group D). Patients were discharged after satisfactory wound closure. Upon discharge patients were followed up at interval of three to six months. Recurrent sternal problems when identified were investigated and additional surgical procedures were carried out when necessary.

RESULTS

There were nine deaths, all due to unrelated causes except in one patient who died of right ventricular rupture (Group C). Nine patients in Group A had recurrent wound problems of which six had VAC system for > 21 days. Three patients underwent extensive debridement due to sternal osteomyelitis. All eight patients in Group B presented with chronic wound-related problems and underwent multiple debridements. Four patients had laparoscopic omental flaps. In contrast 14 patients (Group B and D) who were treated with shorter duration of VAC followed by either a flap or direct surgical closure, did not present with recurrent problems.

CONCLUSION

VAC therapy is a safe and reliable option in the treatment of sternal wound infection. However, prolonged use of VAC system as a replacement for surgical closure of sternal wound appears to be associated with recurrent problems of the sternal wound. Strategy of use of VAC for a short duration followed by early surgical closure appears favorable.

Relationship between pain and upper limb movement in patients with chronic sternal instability following cardiac surgery

Physiotherapists routinely prescribe upper limb exercises for patients who have undergone a median sternotomy during cardiac surgery. It is not currently known whether upper limb exercises should be unilateral or bilateral and conducted with or without additional loading to minimise pain and further sternal separation in patients with sternal instability. Eight patients who had chronic sternal instability after cardiac surgery were included in this study. During a selected regimen of upper limb exercises, the amount of sternal separation at different vertical points on the sternum was measured by ultrasound. The amount of sternal separation was not related to type of upper limb activity, but both unilateral and unilateral loaded positions were found to be significantly associated with sternal pain (p = 0.009). In this group of patients with chronic sternal instability, bilateral upper limb movements were significantly less associated with sternal pain than unilateral movements.

Trunk stabilisation exercises reduce sternal separation in chronic sternal instability after cardiac surgery: a randomised cross-over trial

QUESTION

Do trunk stabilisation exercises reduce sternal separation and pain, and improve the quality and control of the performance of tasks in individuals with chronic sternal instability?

DESIGN

Randomised crossover study with concealed allocation and intention-to-treat analysis.

PARTICIPANTS

Nine individuals with chronic sternal instability following a median sternotomy for cardiac surgery.

INTERVENTION

The experimental intervention consisted of six weeks of trunk stabilisation exercises; the control intervention was no exercises.

OUTCOME MEASURES

Outcomes were sternal separation measured by ultrasound in mm, pain during the performance of nine everyday tasks measured on a 100-mm visual analogue scale, and the quality and control of the performance of two tasks scored on a 100-mm visual analogue scale.

RESULTS

Overall, sternal separation during the period of trunk stabilisation exercises decreased by 6.2 mm (95% CI 3.5 to 8.9) more than during the control period. Overall, pain decreased when performing everyday tasks by 14 mm (95% CI 5 to 23) more than during the control period. Overall, task performance during the period of trunk stabilisation exercises did not improve (mean difference 10 mm, 95% CI -3 to 22) more than during the control period.

CONCLUSION

Trunk stabilisation exercises should be included in the rehabilitation of individuals who experience sternal instability following cardiac surgery. A larger trial is warranted to determine if stabilisation exercises are beneficial in improving the quality and control of task performance.

Measurement of non-physiological movement in sternal instability by ultrasound

PURPOSE

Sternal instability, a complication arising for some patients after sternotomy for cardiac surgery affects their later quality of life and cost of care. However, there are currently few guidelines for its diagnosis, quantification, and monitoring. Ultrasound equipment with associated software for calculating selected video-monitor distances provides one way of quantifying the extent of sternal separation.

DESCRIPTION

This study evaluated the validity and reliability of an ultrasound measurement made by attaching the head of the unit to an extensible stand. First the procedure was tested with bony sterna, and second in the examination of the chests of 8 patients with sternal instability.

EVALUATION

Reliability estimation of the ultrasound measure on bony sterna gave ICC (2, 1) values >0.99, and reliability estimates for the sternal separation measure in the patient group were ICC (2, 1) values between 0.90 and 0.93.

CONCLUSIONS

Therefore gap measurements taken by ultrasound can objectively reflect the extent of bony separation occurring in a group of cardiac surgery patients experiencing sternal instability.

Corpus Sterni Reinforcement Improves the Stability of Primary Sternal Closure in High-Risk Patients

PURPOSE

To compare standard sternal closure techniques with reinforcement longitudinal wire placement in the corpus sterni in high-risk patients undergoing open-heart surgery via median sternotomy.

METHODS

The subjects of this study were 71 high-risk patients, 32 (45%) of whom underwent sternal closure by conventional methods (group 1) and 39 (55%) of whom underwent sternal closure with corpus sterni reinforcement. The patients were followed up for a mean period of 90 days.

RESULTS

In group 2, none of the patients had sternal dehiscence and no revision was required, but in group 1, five (15.5%) patients had sternal dehiscence. This difference was significant between the groups (P = 0.024), but there were no significant differences in mediastinitis and mortality (P > 0.05).

CONCLUSIONS

Our findings suggest that primary sternal closure with longitudinal wire reinforcement on both sides of the corpus sterni will decrease the risk of infection and improve wound-healing in parallel with a decrease in sternal dehiscence.

The management of deep sternal wound infections using vacuum assisted closure (V.A.C.) therapy

A group of international experts met in May 2006 to develop clinical guidelines on the practical application of vacuum assisted closure (V.A.C.)+ therapy in deep sternal wound infections. Group discussion and an anonymous interactive voting system were used to develop content. The recommendations are based on current evidence or, where this was not available, the majority consensus of the international group. The principles of treatment for deep sternal wound infections include early recognition and treatment of infection. V.A.C. therapy should be instigated early, following thorough wound irrigation and surgical debridement. V.A.C. therapy in deep sternal wound infections requires specialist surgical supervision and should only be undertaken by clinicians with adequate experience and training in the use of the technique.

Treatment of postoperative sternal dehiscence with mediastinitis: twenty-four-year use of a single method

OBJECTIVE

Postoperative deep sternal wound infection with dehiscence carries a high mortality rate, a high morbidity rate, and a poor cure rate. We developed a standard protocol of care to treat this complication, achieving primary closure and cure of the infection.

METHODS

From January 1, 1981, through May 31, 2005 (24 years 5 months), we treated 114 patients with dehiscence and mediastinitis. The diagnosis was made from 4 to 56 days (mean, 14.5 days) after surgery. Mean age was 64.3 years (range, 38-84 years); 79 (69%) were obese, and 48 (42%) had diabetes. Ten had previous attempts (1-4) of repair with other methods. Treatment entailed (1) debridement without removal of bone, (2) bilateral dissection of skin and subcutaneous tissue as one layer, (3) implantation of a staggered double-tube irrigation-suction system posterior and another one anterior to the sternum, (4) lateral reinforcement of the sternum and reclosure with a double wire, and (5) a single-layer closure of the subcutaneous tissue and skin.

RESULTS

Of 114 patients, 109 (96%) had mediastinitis, positive for Staphylococcus species in 101 (92.6%). The cure rate was 98% (112/114); hospital stay was 14 days (range, 12-16 days), with no deaths.

CONCLUSIONS

Use of this standard protocol is effective and highly recommended. It spares the sternum, cures the infection, and leaves the patient physically functional without the use of soft tissue flaps.

Topical Application of Bacitracin Ointment Is Associated with Decreased Risk of Mediastinitis after Median Sternotomy

BACKGROUND

The diagnosis of mediastinitis after open-heart surgery is infrequent but dreaded as it carries a high morbidity and mortality. The purpose of this study was to investigate the impact that topical antibacterials would have on the postoperative mediastinitis rate.

METHODS

Data were collected from 2455 consecutive patients who underwent sternotomy and cardiopulmonary bypass for both valvar and ischemic heart disease. Prior to 1999, patients (n = 1036) underwent surgery with standard perioperative intravenous antibiotics but no application of bacitracin. After 1999, patients (n = 1419) underwent surgery with intravenous antibiotics and application of bacitracin ointment to the sternotomy incision after closure.

RESULTS

Cases of mediastinitis occurred in 12 patients (1.2%) not treated with bacitracin, which required re-exploration, sternectomy, and soft tissue closure of the mediastinum. Alternatively, 3 patients (0.2%) in the group treated with bacitracin developed mediastinitis (P < .01). Therefore, the use of topical antibacterials was associated with a 6-fold reduction in the risk of mediastinitis after cardiac surgery. This significant difference in the infection rate was observed even though the percentage of patients with risk factors for mediastinitis was equal to greater than the group not treated with bacitracin. Non-bacitracin versus bacitracin: diabetics, 298 versus 484; emergency operations, 24 versus 50; bilateral internal thoracic grafts, 28 versus 29; and obesity (body mass index >30), 294 versus 396.

CONCLUSIONS

The use of topical antibacterials is associated with a decrease in the risk of mediastinitis after cardiac surgery.

Cultures of sternal wound and mediastinum taken at the end of heart surgery do not predict postsurgical mediastinitis

The aim of the study was to assess of the role of intraoperative cultures taken at the end of major heart surgery (MHS) in the prediction of postoperative mediastinitis (PM) in patients undergoing MHS over a 6-month period in a tertiary university hospital. Just before wound closure, a sample of the sternal border was taken, swabbing back and forth the sternal border and the subcutaneous tissues. A second sample was taken after irrigation of the deep mediastinal structures with 10 mL of Ringer lactate. Swabs were processed semiquantitatively and the mediastinal fluid with a quantitative technique. The observation of one or more colonies per plate was considered a positive culture. Cultures obtained at the end of 229 surgical interventions (227 patients) were positive with the semiquantitative or with the quantitative procedures in 31.0% (95% confidence interval [CI], 25.1-37.4%) and 34.5% (95% CI, 28.4-41.0%) of the times, respectively (P = NS). The number of microorganisms isolated in the wound swab or mediastinal fluid was 91 and 110, respectively. Of the 227 patients, 7 developed an episode of PM (3.1%; 95% CI, 1.2-6.2%) after a median time of 11 days (range, 5-19 days). The microorganisms causing the 7 cases of mediastinitis were not isolated in the intraoperative cultures in any of the cases. The value of intraoperative cultures as a test for prediction of PM depending on the breakpoint chosen were as follows: sensitivity (0%), specificity (66.2-97.3%), and positive (0%) and negative predictive values (96.8-98.0%). We recommend against surveillance cultures taken intraoperatively in patients undergoing MHS.

Surgical-site infection after cardiac surgery: incidence, microbiology, and risk factors

OBJECTIVE

To identify risk factors associated with surgical-site infection according to the depth of infection, the cardiac procedure, and the National Nosocomial Infections Surveillance System risk index.

DESIGN

Prospective survey conducted during a 12-month period.

SETTING

A 48-bed cardiac surgical department in a teaching hospital.

PATIENTS

Patients admitted for cardiac surgery between February 2002 and January 2003.

RESULTS

Surgical-site infections were diagnosed in 3% of the patients (38 of 1,268). Of the 38 surgical-site infections, 20 were superficial incisional infections and 18 were mediastinitis for incidence rates of 1.6% and 1.4%, respectively. Cultures were positive in 28 cases and the most commonly isolated pathogen was Staphylococcus. A National Nosocomial Infections Surveillance System risk index score of 2 or greater was associated with a risk of surgical-site infection (relative risk, 2.4; P < .004). Heart transplantation, mechanical circulatory assistance, coronary artery bypass graft with the use of internal mammary artery, and reoperation for cardiac tamponade or pericard effusion were independent risk factors associated with surgical-site infection.

CONCLUSIONS

Data surveillance using incidence rates stratified by cardiac procedure and type of infection is relevant to improving infection control efforts. Risk factors in patients who developed superficial infection were different from those in patients who developed mediastinitis. Coronary artery bypass graft using internal mammary artery was associated with a high risk of surgical-site infection, and independent factors such as reoperation for cardiac tamponade or pericard effusion increased the risk of infection.

Accuracy of blood culture for early diagnosis of mediastinitis in febrile patients after cardiac surgery

Postsurgical mediastinitis (PSM) remains a major cause of morbidity and mortality in patients undergoing cardiac surgery procedures. Although prompt diagnosis is crucial in these patients, neither clinical data nor imaging techniques have shown enough sensitivity or specificity for early diagnosis of PSM. The aim of the present study was to assess the validity of blood cultures as a diagnostic test for the early detection of PSM in patients who become febrile after cardiac surgery procedures. During a 4-year period (1999-2002), patients who developed fever (>37.8 degrees C) in the first 60 days after a cardiac surgery procedure were evaluated. Blood cultures were drawn from these patients. PSM was defined as deep infection involving retrosternal tissue and/or the sternal bone directly observed by the surgeon and confirmed microbiologically. Three criteria for positivity of blood cultures were applied: bacteremia, staphylococcal bacteremia, or Staphylococcus aureus bacteremia. For purposes of the analysis, a positive blood culture in patients with PSM was considered a true-positive test and a negative blood culture a false-negative test. Otherwise, in febrile patients without PSM in the postsurgery period, a positive blood culture was considered a false-positive test and a negative blood culture a true-negative test. Blood cultures were drawn from 266 febrile patients in the postsurgery period. PSM occurred in 38 patients (26 cases due to S. aureus, 8 to Staphylococcus epidermidis, 3 to gram-negative enteric bacteria, and one to Pseudomonas aeruginosa). Within the 60-day postsurgical period, blood culture as a diagnostic test was most accurate in patients with S. aureus bacteremia, providing 68% sensitivity, 98% specificity, a positive predictive value of 87%, and a negative predictive value of 95%. If the analysis was limited to the period during which patients are at maximum risk for PSM (day 7-20), the values in patients with S. aureus bacteremia were as follows: 73% sensitivity, 98% specificity, 90% positive predictive value, and 93% negative predictive value. Blood culture is an accurate test for the early diagnosis of PSM in febrile patients after cardiac surgery, particularly in institutions where S. aureus is prevalent in this context. A negative blood culture practically excludes PSM and, during the period of maximum risk for PSM, the presence of S. aureus bacteremia should compel early surgical management.

Acute poststernotomy mediastinitis managed with debridement and closed-drainage aspiration: Factors associated with death in the intensive care unit

OBJECTIVE

The purpose of the study is to describe an intensive care unit's experience in the treatment of poststernotomy mediastinitis and to identify factors associated with intensive care unit death.

METHODS

Over a 10-year period, 316 consecutive patients with mediastinitis occurring less than 30 days after sternotomy were treated in a single unit. First-line therapy was closed-drainage aspiration with Redon catheters. Variables recorded, including patient demographics, underlying disease classification, clinical and biologic data available at intensive care unit admission and day 3, and their association with intensive care unit mortality, were subjected to multivariate analyses.

RESULTS

Intensive care unit mortality (20.3%) was significantly associated with 5 variables available at admission: age greater than 70 years (odds ratio, 2.70), operation other than coronary artery bypass grafting alone (odds ratio, 2.59), McCabe class 2/3 (odds ratio, 2.47), APACHE II score (odds ratio, 1.12 per point), and organ failure (odds ratio, 2.07). After introducing day 3 variables into the logistic regression model, independent risk factors for intensive care unit death were as follows: age greater than 70 years, operations other than coronary artery bypass grafting alone, McCabe class 2/3, APACHE II score, mechanical ventilation still required on day 3, and persistently positive bacteremia. For patients receiving mechanical ventilation for less than 3 days, mortality was very low (2.4%). In contrast, for patients receiving mechanical ventilation for 3 days or longer, mortality reached 52.8% and was associated with non-coronary artery bypass grafting cardiac surgery, persistently positive bacteremia, and underlying disease.

CONCLUSIONS

In patients requiring intensive care for acute poststernotomy mediastinitis, age, type of cardiac surgery, underlying disease, and severity of illness at the time of intensive care unit admission were associated with intensive care unit death. Two additional factors (mechanical ventilation dependence and persistently positive bacteremia) were identified when the analyses were repeated with inclusion of day 3 patient characteristics.

Primary or delayed closure for the treatment of poststernotomy wound infections?

OBJECTIVE

The methods of primary versus delayed wound closure for the treatment of sternal wound infections after cardiac surgery were retrospectively compared.

METHODS

From January 2001 to March 2003, 132 patients (median age 66 years, male to female ratio 88:44) with sternal wound infection after cardiac surgery were treated at our department. After thorough debridement, 35 patients received preconditioning of the wound before implementation of definitive therapy; the remainder (97 patients) were treated with immediate closure.

RESULTS

From the 35 patients with preconditioning, 19 patients proceeded to delayed primary closure, whereas the remaining 14 patients were referred to plastic reconstruction with a pectoralis muscle flap. Primary success rate in this group was 100%. In the immediate primary closure group, 33 patients experienced 1 or more therapy failures, resulting in a recurrence rate of 39%. Fifteen patients received a pectoralis muscle flap as definite treatment modality.

CONCLUSIONS

Immediate primary closure is associated with a high rate of local infection recurrence. Surgical debridement and conditioning of the wound until resolution of infections with delayed primary closure or plastic reconstruction is suggested as the more appropriate treatment modality, with promising results.

Management of Sternal Wounds With Pectoralis Major Musculocutaneous Advancement Flaps in Patients With a History of Chest Wall Irradiation

Although debridement and pectoralis major musculocutaneous advancement flap closure has proved to be an effective treatment of sternal wounds in the general population, the purpose of this study was to examine the use of these flaps in patients with previously irradiated chest walls. The authors examined 5 patients with a history of breast cancer and chest wall radiation therapy who developed poststernotomy wound complications that were treated with debridement and pectoralis major musculocutaneous advancement flaps. The average patient age was 76 years. Three patients had previously undergone a radical mastectomy and had only 1 pectoralis major muscle remaining. There were no intraoperative deaths. One patient died during the 30-day postoperative period. There were no hematomas, seromas, or dehiscences. One woman developed a postoperative wound infection. Functional and aesthetic results were excellent. This study demonstrates that early, aggressive sternal debridement and closure with pectoralis major musculocutaneous advancement flaps is effective in patients with a history of chest wall irradiation, including those who have had 1 pectoralis major muscle previously resected.

10-Year follow-up of patients with and without mediastinitis

Mediastinitis is a dreaded complication of CABG surgery. Short-term outcomes have been described, but there have been only a few long-term studies. We examined the survival of patients undergoing isolated CABG surgery between 1992 and 2001. Mediastinitis was identified during the index admission. Proportional hazards regression was used to calculate adjusted hazard ratios (HR) and 95% confidence intervals (CI 95%). Among 36,078 consecutive patients, there were 5749 deaths during 148,319 person years of follow-up. There were 418 cases of mediastinitis (1.16%). The incidence of death was 11.15 per 100 person/years with mediastinitis and 3.81 deaths/100 person years without. (P < 0.001). We also examined the mortality rates of patients who survived at least 6 months after their CABG surgery. Patients with mediastinitis had an incidence rate of 5.70 deaths per 100 person/years while those without had a rate of 2.66 deaths per 100 person/years (P < 0.001). After adjustment for baseline differences in patient and disease characteristics, the hazard ratio was 2.12 (CI95% = 1.86,2.58; P < 0.001). The adjusted hazard ratios for patients who survived 6 months postsurgery was 1.70 (CI95% = 1.36,2.13; P < 0.001). Mediastinitis is associated with a marked increase in both acute and long-term mortality rates.

A modified parasternal wire technique for prevention and treatment of sternal dehiscence

BACKGROUND

Sternal dehiscence with or without mediastinitis is a devastating complication of median sternotomy. Various techniques of sternotomy closure including 'figure of eight' wire sutures, nylon bands, and custom-made titanium-H plates have been described. We have devised and tested a new method of sternal closure to prevent sternal wound complications in patients at high risk of sternal dehiscence.

METHODS

1336 patients underwent sternotomy for various cardiac operations from January 1996 to January 2002. Patients were divided into two groups. Group I consisted of 560 patients who did not have any high risk factors for sternal dehiscence and received a standard six wire closure. Group II comprised of patients at high risk of sternal dehiscence and were divided randomly into subgroup II A (n = 390), which included patients who had conventional sternal closure. While in subgroup II B (n = 386) patients had a modified parasternal wire closure according to the finalized protocol.

RESULTS

Sternal instability was noticed in 1/560 and none had sternal dehiscence in group I, but 16/390 patients had sternal instability and 3/390 had sternal dehiscence in subgroup II A, whereas only one patient in high risk subgroup II B developed sternal dehiscence with mediastinitis and required a pectoral flap advancement for sternal closure.

CONCLUSIONS

Use of modified parasternal wire closure in patients with a high risk of sternal dehiscence is a safe, effective, technically easily reproducible, as well as economical, method of preventing and treating sternal dehiscence.

Deep sternal wound infection: a sternal-sparing technique with vacuum-assisted closure therapy

BACKGROUND

Vacuum-assisted closure therapy is a novel treatment employed to aid wound healing in different areas of the body and recently also in sternotomy wounds. Aggressive vacuum-assisted closure treatment of the sternum in postoperative deep wound infection enhances sternal preservation and the rate of possible rewiring.

METHODS

The records of 40 consecutive patients with deep sternal wound infection were reviewed. Sternal bone sparing was achieved by using layers of paraffin gauze (Jelonet; Smith and Nephew Medical, Hull, UK) at the bottom of the wound in order to cover and protect visible parts of the right ventricle, lung tissue, and grafts from the sternal edges. Two separate layers of polyurethane foam (KCI, Copenhagen, Denmark) were placed so as to fit between the sternal edges and subcutaneously. A continuous negative pressure of 125 mm Hg was applied and subsequent revision was made exclusively in nongranulation areas.

RESULTS

There were no deaths during the 90 days of follow-up. Three late deaths unrelated to the infection and three subcutaneous fistulas occurred during the total follow-up period (3 to 41 months). The median duration of the vacuum-assisted closure therapy was 10 days (range, 3 to 34). The series represents a total of 474 days with the vacuum-assisted closure device without serious adverse events.

CONCLUSIONS

In our opinion this modified vacuum-assisted closure therapy is a safe and reproducible option to bridge patients with postoperative deep sternal wound infection to complete healing. Reconstruction of the sternum was achieved in all patients without the use of muscle or omental flap surgery.

[Plastic surgery procedures in the treatment of mediastinitis in adult]

Closed vacuum drainage is becoming the standard technique in most early postoperative mediastinitis, open wound treatment being only necessary in case of failure of the previous technique or in high grade mediastinitis. The reconstruction technique to be chosen depends on both resulting wound presentation after debridement and thorax morphology. Mediastinal dead space obliteration is a "sine qua non" for success often requiring multiple flap transposition. Since 1983, reconstructive procedures were carried out in 205 patients, of them 95 had bilateral pectoralis major turn-over transposition flaps on internal pedicules, following internal mammary artery coronary revascularisation in 45. Trapezius and latissimus dorsi were the next most used flaps. Transposition of the omentum although especially well suited for torpid wounds was to often precluded by bad abdominal risk factors. Conservative closed drainage salvaged by reconstructive procedures when necessary has greatly improved both survival and functional outcome of these patients.

Sternal puncture allows an early diagnosis of poststernotomy mediastinitis

OBJECTIVES

Poststernotomy mediastinitis after cardiac operations is a nosocomial infection involving the mediastinal space and the sternum, with a high mortality rate mostly related to a late diagnosis. We investigated whether sternal puncture might facilitate and shorten the delay in the diagnosis of mediastinitis.

METHODS

Of 1024 patients undergoing sternotomy for cardiac surgery, sternal puncture was performed in a subgroup of 49 patients in whom mediastinitis was suspected.

RESULTS

Sternal puncture culture results were positive for all patients with true mediastinitis (n = 23) and negative in 24 of 26 patients without mediastinitis. In addition, sternal puncture allowed diagnosis of mediastinitis with a shorter delay (9 +/- 5 days vs 13 +/- 8 days, P =.04) and caused a reduction in the length of mechanical ventilation (3 +/- 4 days vs 10 +/- 13 days, P =.02) and stay in the intensive care unit (9 +/- 7 days vs 18 +/- 15 days, P =.02) compared with that found in another group of patients (n = 20) operated on for true mediastinitis on the basis of the presence of classic, delayed, clinical signs.

CONCLUSIONS

Our study shows that sternal puncture is a rapid and safe method to ensure the diagnosis of poststernotomy mediastinitis.

The vacuum-assisted closure system for the treatment of deep sternal wound infections after cardiac surgery

BACKGROUND

The VAC system (vacuum-assisted wound closure) is a noninvasive active therapy to promote healing in difficult wounds that fail to respond to established treatment modalities. The system is based on the application of negative pressure by controlled suction to the wound surface. The method was introduced into clinical practice in 1996. Since then, numerous studies proved the effectiveness of the VAC System on microcirculation and the promotion of granulation tissue proliferation.

METHODS

Eleven patients (5 men, 6 women) with a median age of 64.4 years (range 50 to 78 years) with sternal wound infection after cardiac surgery (coronary artery bypass grafting = 5, aortic valve replacement = 5, ascending aortic replacement = 1) were fitted with the VAC system by the time of initial surgical debridement.

RESULTS

Complete healing was achieved in all patients. The VAC system was removed after a mean of 9.3 days (range 4 to 15 days), when systemic signs of infection resolved and quantitative cultures were negative. In 6 patients (54.5%), the VAC system was used as a bridge to reconstructive surgery with a pectoralis muscle flap, and in the remaining 5 patients (45.5%), primary wound closure could be achieved. Intensive care unit stay ranged from 1 to 4 days (median 1 day). Duration of hospital stay varied from 13 to 45 days (median 30 days). In-hospital mortality was 0%, and 30-day survival was 100%.

CONCLUSIONS

The VAC system can be considered as an effective and safe adjunct to conventional and established treatment modalities for the therapy of sternal wound infections after cardiac surgery.

Deep sternal wound infection: the role of early debridement surgery

OBJECTIVE

This retrospective chart review study aimed to evaluate whether a more aggressive staged approach can reduce morbidity and mortality following post-cardiotomy deep sternal wound infection.

METHODS

Between 1979 and 2000, 14620 patients underwent open heart surgery: mediastinitis developed in 124 patients (0.85%). Patients were divided in two groups: in 62 patients (Group A) (1979-1994) an initial attempt of conservative antibiotic therapy was the rule followed by surgical approach in case of failure; in 62 patients (Group B) (1995-2000) the treatment was staged in three phases: (1) wound debridement, removal of wires and sutures, closed irrigation for 10 days; (2) in case of failure open dressing with sugar and hyperbaric therapy (11 patients, 17%); (3) delayed healing and negative wound cultures mandated plastic reconstruction (three patients, 4%). Categorical values were compared using the Chi-square test, continuous data were compared by unpaired t-test.

RESULTS

Incidence of mediastinitis was higher in Group B (62 out of 5535; 1.3%) than in Group A (62 out of 9085; 0.7%) (P=0.007). Mean interval between diagnosis and treatment was shorter in Group B (18+/-6 days) than in group A (38+/-7 days) (P=0.001). Hospital mortality was higher in Group A (19/62; 31%) than in Group B (1 out of 62; 1.6%) (P<0.001). Hospital stay was shorter in Group B (30.5+/-3 days) than in group A (44+/-9 days) (P=0.001). In Group B complete healing was observed in all the 61 survivors: 47 cases (76%) after Stage 1; 11 (18%) after Stage 2; three (4.8%) after Stage 3.

CONCLUSIONS

Although partially biased by the fact that the two compared groups draw back to different decades, this study showed that an aggressive therapeutic protocol can significantly reduce morbidity and mortality of deep sternal wound infection.

Closed drainage using redon catheters for poststernotomy mediastinitis: results and risk factors for adverse outcome

BACKGROUND

Several different surgical techniques have been described for the treatment of poststernotomy mediastinitis. The present study was undertaken to evaluate the midterm results of primary closed drainage using Redon catheters and to identify risk factors for adverse outcome.

METHODS

Hospital records of 72 patients in whom poststernotomy mediastinitis developed and who underwent closed drainage with Redon catheters between April 1, 1996, and December 31, 1999, were reviewed. Follow-up was complete and averaged 11.8 +/- 11.5 months.

RESULTS

Of the 25 deaths (34.7%) recorded, 15 were directly attributable to mediastinitis. Actuarial estimates for freedom from mediastinitis-related death were 80.1% at 1 month and 77.4% at 1 year, 2 years, and 3 years. Logistic regression identified older age (odds ratio, 1.1; 95% confidence interval, 1.02 to 1.18), incubation time of 14 days or less (6.5; 1.33 to 31.4), and methicillin-resistant Staphylococcus aureus (5.8; 1.2 to 27.2) as independent risk factors for mediastinitis-related death. Reintervention for recurrent mediastinitis was necessary in 9 patients (12.5%) and occurred at a mean interval of 18.7 +/- 13.5 days from the first debridement. Actuarial estimates for freedom from reintervention were 87.1% at 1 month and 85.2% at 1 year, 2 years, and 3 years. The combined end point of treatment failure (mediastinitis-related death or reintervention) was recorded in 9 patients (26.4%). Actuarial estimates for freedom from treatment failure were 74.3% at 1 month and 72.7% at 1 year, 2 years, and 3 years. Logistic regression identified older age (1.01; 1.02 to 1.18), preoperative renal insufficiency (6.8; 1.04 to 44.5), and methicillin-resistant S aureus infection (4.8; 1.04 to 22.33) as independent risk factors for treatment failure (includes mediastinitis-related death and reintervention [with or without death]).

CONCLUSIONS

Primary closed drainage using Redon catheters is an effective and simple treatment for most patients in whom poststernotomy mediastinitis develops. However, patients with methicillin-resistant S aureus infection or recurrent mediastinitis may benefit from a more aggressive approach.

Variables predicting adverse outcome in patients with deep sternal wound infection

BACKGROUND

Mortality after deep sternal wound infection (DSWI) ranges between 5% and 47%. Variables predicting hospital mortality and prolonged hospital stay are still to be assessed.

METHODS

Among 13,420 patients who underwent cardiac surgery in our institution between 1979 and 1999, DSWI developed in 112 cases (0.8%). Multiple variables were recorded prospectively and analyzed retrospectively as predictors of hospital death and prolonged (>30 days) hospital stay. The analyzed variables were divided into three groups: (1) related to the patient, including demographic variables and preoperative conditions; (2) related to cardiac operation; and (3) related to infection. Predictive variables were assessed by univariate and multivariate logistic regression analysis.

RESULTS

Hospital mortality was 16.9%. The hospital stay of the 93 discharged patients ranged between 16 and 180 days (mean 31.3 +/- 15.2). Length of cardiac operation, length of stay in intensive care unit, interval between symptoms of DSWI and wound debridement were found to be the most significant predictors of bad outcome following DSWI.

CONCLUSIONS

In our study demographic variables and preoperative conditions did not affect the prognosis of DSWI. Lower mortality rate and shorter hospital stay could be achieved with earlier and aggressive treatment of DSWI.

Mediastinitis and long-term survival after coronary artery bypass graft surgery

BACKGROUND

Mediastinitis is a dreaded complication of coronary artery bypass surgery (CABG). The long-term effect of mediastinitis on mortality after CABG has not been well studied.

METHODS

We examined the survival of 15,406 consecutive patients undergoing isolated CABG surgery from 1992 through 1996. Patient records were linked to the National Death Index. Mediastinitis was defined as occurring during the index admission and requiring reoperation.

RESULTS

Mediastinitis occurred in 193 patients (1.25%). Patients with mediastinitis were older and more likely to have had emergency surgery, diabetes, peripheral vascular disease, chronic obstructive pulmonary disease, and preoperative dialysis-dependent renal failure. Patients with mediastinitis were also more likely to be severely obese and had somewhat lower preoperative ejection fraction. After multivariate adjustment for these factors, the first year post-CABG survival rate was 78% with mediastinitis and 95% without, and the hazard ratio for mortality during the entire follow-up period was 3.09 (CI 95% 2.28, 4.19; p < 0.0001).

CONCLUSIONS

Mediastinitis is associated with a marked increase in mortality during the first year post-CABG and a threefold increase during a 4-year follow-up period.

Coagulase-negative staphylococci and sternal infections after cardiac operation

BACKGROUND

Coagulase negative staphylococci (CoNS) have been recognized as important pathogens in nosocomial infections, especially in connection with implanted foreign materials. In cardiac operation they are among the most common pathogens isolated from infected sternal wounds. The definition of the infection is very important. In this study we focus on deep postoperative chest infections.

METHODS

By studying 33 infected patients retrospectively and comparing them to 33 matched uninfected controls, we studied the characteristics and costs of the infections.

RESULTS

Typical for these infections is the late and insidious onset, and that the infections initially give only minor symptoms such as pain, redness, and serous secretion. We found the following risk factors for infection: number of preoperative days in a hospital, the total length of the operation, and if the patient had undergone an early reoperation due to causes other than infection. This kind of infection more than doubled the hospital costs for the patients affected.

CONCLUSIONS

Coagulase negative staphylococci are the most important pathogens in deep postoperative infections in this material. They cause infections that are difficult to recognize since they give only discrete symptoms and start well after the patients leave the hospital. The risk factors for patients with CoNS infections are mostly associated with a long exposure to the hospital environment. The treatment is often difficult and costly because of multiresistant bacteria and frequent need for repeated surgical revisions.