Johan Sjögren

Effects of vacuum‐assisted closure therapy on inguinal wound edge microvascular blood flow

Vacuum‐assisted closure (VAC) therapy has been shown to facilitate wound healing. Data on the mechanisms are scarce, although beneficial effects on blood flow and granulation tissue formation have been presented. In the current study, laser Doppler was used to measure microvascular blood flow to an inguinal wound in pigs during VAC therapy (− 50 to − 200 mmHg), including consideration of the different tissue types and the distance from the wound edge. VAC treatment induced an increase in microvascular blood flow a few centimeters from the wound edge. The increase in blood flow occurred closer to the wound edge in muscular as compared to subcutaneous tissue (1.5 cm and 3 cm, at − 75 mmHg). In the immediate proximity to the wound edge, blood flow was decreased. This hypoperfused zone was increased with decreasing pressure and was especially prominent in subcutaneous as compared to muscular tissue (0–1.9 cm vs. 0–1.0 cm, at − 100 mmHg). When VAC therapy was terminated, blood flow increased multifold, which may be due to reactive hyperemia. In conclusion, VAC therapy affects microvascular blood flow to the wound edge and may thereby promote wound healing. A low negative pressure during treatment may be beneficial, especially in soft tissue, to minimize possible ischemic effects. Intermittent VAC therapy may further increase blood flow.

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.

Transapical Versus Transfemoral Aortic Valve Implantation: A Comparison of Survival and Safety

BACKGROUND Transcatheter aortic valve implantation (TAVI) is a therapeutic option for high-risk patients with aortic stenosis. Procedural mortality remains high in comparison with conventional aortic valve replacement (AVR) because patients determined for TAVI are commonly denied conventional surgery. We aimed to evaluate access-related complications between the transfemoral (TF) and the transapical (TA) approach and to compare survival between TAVI and conventional AVR in propensity-score-matched patients. METHODS Between January 2008 and November 2009, 40 patients underwent TAVI (TF, n=10; TA, n=30) with the Edwards Sapien bioprosthesis (Edwards Lifesciences, Irvine, CA). Survival and postoperative complications were evaluated between the TF and the TA approach. A comparison of survival was made between the TAVI patients and propensity-score-matched patients undergoing conventional AVR. RESULTS Successful implantation rate was 92.5% (37 of 40). Thirty-day mortality was 5.0% (2 of 40), and the overall in-hospital mortality was 10.0% (4 of 40). Survival after TAVI was 77% at both 6 months and 1 year. Major vascular complications occurred in 3 of 10 patients (all in the TF group), and 3 of 40 patients (7.5%) suffered cerebrovascular events. A comparison of survival between TAVI and propensity score-matched conventional AVR patients showed no significant difference in either the TA group (p=0.73) or the TF group (p=0.59). CONCLUSIONS The vascular complications occurring when using the TF approach were probably related to a combination of a wide introducer sheath and heavily calcified femoral arteries in a high-risk population. No serious complications were encountered when using the TA approach. After propensity-score matching, survival with both the TA and TF approaches is similar to that after AVR.

Comparative outcome of double lung transplantation using conventional donor lungs and non-acceptable donor lungs reconditioned ex vivo

A method to evaluate and recondition lungs ex vivo has been tested on donor lungs that have been rejected for transplantation. In the present paper, we compare early postoperative course between the six patients who received reconditioned lungs and the patients who received conventional donor lungs during the same period of time. During 2006 and 2007, a total of 21 patients underwent double sequential lung transplantation at the University Hospital of Lund. Six of those patients received reconditioned lungs. The other 15 patients received conventional donor lungs for transplantation without reconditioning ex vivo. The results are presented as median and interquartile range. Time in intensive care unit (days) between recipients of reconditioned lungs [13 (5-24) days], and recipients of conventional donor lungs [7 (5-12) days], P=0.44. Total hospital stay after transplantation (days) between recipients of reconditioned lungs [52 (47-60) days] and recipients of conventional donor lungs [44 (37-48) days], P=0.9. Ex vivo lung evaluation and reconditioning might not prolong early postoperative course in double lung transplantation. However, given the small number of patients, there might be a failure to detect a difference between the two groups.

Quality of Life in the Very Elderly after Cardiac Surgery: A Comparison of SF-36 between Long-Term Survivors and an Age-Matched Population

Background: Octogenarians are the fastest growing section of the population in Western countries. Since health care resources are limited, there is a need for critical evaluations of the long-term surgical outcome and quality of life in the elderly. Objectives: Our aim was to assess the quality of life and long-term survival after cardiac surgery in the very elderly. Methods: Between 1990 and 1993, 117 octogenarians underwent aortic valve replacement, coronary artery bypass grafting or combined surgery at our department. Forty-one patients were still alive at the time of follow-up (mean 8.3 ± 1.9 years). Thirty-nine of the 41 long-term survivors (95%) answered a quality of life questionnaire (SF-36). The scores were compared with an age-matched population. Results: The overall survival at 1, 5 and 9 years was 92.3 ± 2.5, 65.0 ± 4.4 and 37.9 ± 5.2%, respectively. A significant difference was identified between the scores of our patients and the general Swedish octogenarians in two SF-36 headings (Bodily Pain and Physical Functioning). Our patients indicated lower physical function, but less pain in comparison with the general aged population. There was no significant difference in six of the eight SF-36 headings. Conclusions: The overall long-term survival was similar to Swedish octogenarians. Late postoperative quality of life in our long-term survivors was comparable to an age-matched population. Our findings support the view that a selected population of elderly may undergo open heart surgery with good long-term quality of life.

The effect of vacuum-assisted closure therapy on the pig femoral artery vasomotor responses.

Vacuum‐assisted closure (VAC) is frequently used to treat wound infections. The aim of the present study was to evaluate the effect of VAC therapy on blood vessels. Vasodilatation and vasoconstriction were studied in isolated ring segments of the pig femoral artery after continuous VAC therapy of an inguinal wound for 12 hours. Vasoconstriction induced by endothelin‐1 (ET‐1), which is mainly an endothelin type A receptor agonist (Emax = 181 ± 2% of potassium), and the endothelin type B receptor agonist, sarafotoxin 6c (Emax = 30 ± 1%), were significantly increased after VAC therapy (ET‐1; 325 ± 3% and sarafotoxin 6c; 69 ± 1%). The norepinephrine‐, phenylephrine‐, and angiotensin II‐induced vasoconstrictions were not affected by VAC therapy. Acetylcholine induced an endothelium‐dependent dilatation that was enhanced after VAC therapy (Rmax = 38 ± 1% of norepinephrine‐preconstriction after sham and 47 ± 1% after VAC therapy, p < 0.05). The dilatory response was mediated by nitric oxide (Rmax = 39 ± 1%), prostaglandins (5 ± 1%) and endothelium‐derived hyperpolarizing factor (16 ± 1%), which were all significantly increased after VAC therapy. In conclusion, VAC therapy for 12  hours enhances an endothelin type A and type B receptor‐mediated vasoconstriction. This may be compensated for by a more efficacious endothelium‐dependent vasodilatation. No spontaneous bleeding, perforation, dissection, or other macroscopic change could be observed in the arteries exposed to VAC therapy.

The cost of vacuum-assisted closure therapy in treatment of deep sternal wound infection.

Objectives. Surgical sites infections are very expensive and the total costs for coronary artery bypass grafting (CABG) surgery followed by deep sternal wound infection (DSWI) with conventional therapy are estimated to be 2.8 times that for normal, CABG surgery. Promising results have been reported with vacuum-assisted closure (VAC) therapy in patients with DSWI. This study presents the cost of VAC therapy in patients with DSWI after CABG surgery. Design. Thirty-eight CABG patients with DSWI, between 2001 and 2005, were treated with VAC therapy. The cost of surgery, intensive care, ward care, laboratory tests and other costs were analyzed. Results. No three-month mortality or recurrent infection was observed. The average cost of CABG procedure and treatment of DSWI was 2.5 times higher than the mean cost of CABG alone. No significant correlations were found between the preoperative EuroSCORE and the cost of DSWI therapy. Conclusions. VAC therapy for patients who underwent CABG surgery followed by DSWI seems to be cost effective, and has low mortality rate.

Mechanisms governing the effects of vacuum-assisted closure in cardiac surgery.

Summary: Vacuum-assisted closure has been adopted as the first-line treatment for poststernotomy mediastinitis as a result of the excellent clinical outcome achieved with its use. Scientific evidence regarding the mechanisms by which vacuum-assisted closure promotes wound healing has started to emerge, although knowledge regarding the effects on heart and lung function is still limited. The organs in the mediastinum are hemodynamically crucial, and in patients with poststernotomy mediastinitis, vulnerable bypass grafts and reduced cardiac function must be taken into consideration during vacuum-assisted closure therapy. This article provides an overview of the effects of vacuum-assisted closure on heart and lung function and summarizes the current knowledge on the mechanisms by which vacuum-assisted closure therapy promotes wound healing.

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.

Negative-pressure wound therapy for deep sternal wound infections reduces the rate of surgical interventions for early re-infections

OBJECTIVES To evaluate the outcome of treatment for deep sternal wound infection (DSWI) in a nationwide patient cohort, before and after the introduction of negative-pressure wound therapy (NPWT). METHODS This was a population-based cohort of all patients treated for DSWI in Iceland out of 2446 open heart operations performed between 2000 and 2010. Length of hospital stay, survival and reoperations were compared in (i) 23 patients treated with open and/or closed irrigation before August 2005 (conventional treatment, CvT group) and in (ii) 20 patients treated after this time with NPWT as a first-line therapy (NPWT group). RESULTS The DSWI rate was 1.8% and did not change during the study period. Demographics were similar for both groups, except for peripheral arterial disease which was less common in the NPWT group. Coagulase-negative staphylococci were also more common (as the only pathogen identified) in the NPWT group (70% vs 30%, P = 0.01). The median length of hospital stay was 43 days in both groups and the sternum could be closed with delayed primary closure in all except 2 patients, one in each group. Eight patients in the CvT group required surgical revision for re-infections, including debridement and rewiring, when compared with 1 patient in the NPWT group (P = 0.02). Furthermore, 6 patients in the CvT group developed late chronic infections of the sternum requiring surgical revision, compared with one in the NPWT group (P = 0.10). The 30-day mortality was not significantly different between groups (4% vs 0%, P > 0.1) and the same was true for 1-year mortality (17% vs 0%, P = 0.11). CONCLUSIONS NPWT significantly reduces the risk of early re-infections in patients with DSWI. There was a lower rate of late chronic sternal infections and lower mortality in the NPWT group, but the difference was not statistically significant. We conclude that NPWT should be considered as a first-line treatment for most DSWIs.