Trends in postcoronary artery bypass graft sternal wound dehiscence in a provincial population

BACKGROUND:

It appears that the medical profile of patients undergoing coronary artery bypass graft (CABG) surgery has changed. The impact of this demographic shift on CABG outcomes, such as sternal wound dehiscence, is unclear.

OBJECTIVES:

To quantify the incidence and trends of sternal wound dehiscence, quantify the demographic shift of those undergoing CABG and identify patient factors predictive of disease.

METHODS:

A prospective analysis was performed on a historical cohort of consecutive patients who underwent CABG (without valve replacement) in Alberta between April 1, 2002 and November 30, 2009. The incidence and trends of sternal wound dehiscence were determined. In addition, the trend of the mean Charlson index score and European System for Cardiac Operative Risk Evaluation (EuroSCORE) (capturing patient comorbidities) was analyzed. Univariable analysis and multivariable models were performed to determine factors predictive of wound dehiscence.

RESULTS:

A total of 5815 patients underwent CABG during the study period. The incidence proportion of sternal wound dehiscence in Alberta was 1.86% and the incidence rate was 1.98 cases per 100 person-years. Although both the EuroSCORE and Charlson scores significantly increased over the study period, the incidence of sternal wound dehiscence did not change significantly. Factors predictive of sternal wound dehiscence were diabetes (OR 2.97 [95% CI 1.73 to 5.10]), obesity (OR 1.55 [95% CI 1.05 to 2.27]) and female sex (OR 1.90 [95% CI 1.26 to 2.87]).

CONCLUSIONS:

The incidence proportion of sternal wound dehiscence in Alberta was comparable with the incidence previously published in the literature. While patients undergoing CABG had worsening medical profiles, the incidence of sternal wound dehiscence did not appear to be increasing significantly.     

Sternotomy infections: sternal salvage and the importance of sternal stability

Objective

To review the management of sternal wound infections after cardiovascular surgery.

Design

Retrospective case study.

Setting

All management took place in a single tertiary-care university hospital.

Patients

Twenty-one consecutive patients seen over a 3-year period who had infected median sternotomy incisions after cardiovascular surgery.

Interventions

Surgical eradication of infection, including sternal débridement and rewiring or placement of vascularized muscle flaps, or both.

Main Outcome Measures

Resolution of infection and restoration of sternal stability.

Results

The development of sternal wound infection was found to be associated with sternal instability. In 12 of 17 patients treated initially with sternal débridement and rewiring the infection was cured. Vascularized muscle flap transfers were required to eradicate the infection in the remaining patients.

Conclusions

Sternal débridement and rewiring is an effective initial treatment for sternal wound infections in selected patients. Some patients may require placement of muscle flaps for definitive treatment.     

Randomized,multicenter trial comparing sternotomy closure with rigid plate fixation to wire cerclage

Objective

To evaluate sternal healing, complications, and costs after sternotomy closure with rigid plate fixation or wire cerclage.

Post-trauma “abrasive” right ventricular rupture without mediastinitis early post-CABG. Is the Robicsek closure technique necessary for all elderly patients?

INTRODUCTION

Right ventricular (RV) rupture with mediastinitis, is a very rare but extremely dangerous (even fatal) complication, following CABG surgery.

PRESENTATION OF CASE

In this paper, we present the case of a post-trauma (after fall) RV rupture (without mediastinitis) in a patient who had undergone cardiac surgery several days ago. The cause of the rupture proved to be a broken bone piece from the lower sternal edge.

DISCUSSION

RV rupture post-operatively caused by broken bone pieces or bone dislocation may occur through two mechanisms: either penetration of the RV, or through the “sandpaper effect”. In order to prevent the rupture, we should be able to recognize patients with aggravating factors (age, weight) and choose intra-operatively a suitable closure technique.

CONCLUSION

We propose that the technique that could prevent such ruptures is the Robicsek technique.     

Sternal wound tuberculosis following cardiac operations: a review

Objective

The diagnosis and treatment of sternal wound infections with mycobacteria are challenging. Such an infection is often associated with a delayed diagnosis and improper treatment that may lead to a worsened clinical outcome. The present study is designed to highlight its clinical features so as to facilitate a prompt diagnosis and timely treatment.

Methods

MEDLINE, Highwire Press, and Google search engine were searched for publications in the English language, with no time limit, reporting on sternal wound infection caused by tuberculosis after cardiac surgery.

Results

A total of 12 articles reporting on 14 patients were included in this study. Coronary artery bypass grafting was the underlying surgical procedure in more than half of the cases. Purulent discharge and cold abscess were the two main presenting symptoms. Diagnosis of sternal wound infection was evidenced in all 14 patients by different investigations, with culture of samples being the most sensitive method of identifying the pathogen. Good response to first-line anti-tuberculous agents was noted. Almost all patients required surgical debridement/resection and, sometimes, sternal reconstruction. A delayed diagnosis of sternal wound infection may lead to repeated recurrences. A comparison between patients with sternal wound infection due to tuberculosis and non-tuberculous mycobacterial infections showed that the former infections took an even longer period of time. Comparisons also revealed patients with sternal tuberculosis infection had a significantly higher mortality than patients with sternal non-tuberculous infection (29.2% vs. 0%, P=0.051).

Conclusion

Sternal infection caused by tuberculosis after cardiac surgery has a longer latency, better response to first-line drugs, and better outcomes in comparison with non-tuberculous sternal infection. Early diagnosis and early anti-tuberculous treatment can surely improve the patients'' prognosis.     

Biomechanical analysis of two fixation methods for proximal chevron osteotomy of the first metatarsal

Purpose

The proximal chevron osteotomy provides high correctional power. However, relatively high rates of dorsiflexion malunion of up to 17 % are reported for this procedure. This leads to insufficient weight bearing of the first ray and therefore to metatarsalgia. Recent biomechanical and clinical studies pointed out the importance of rigid fixation of proximal metatarsal osteotomies. Therefore, the aim of the present study was to compare biomechanical properties of fixation of proximal chevron osteotomies with variable locking plate and cancellous screw respectively.

Methods

Ten matched pairs of human fresh frozen cadaveric first metatarsals underwent proximal chevron osteotomy with either variable locking plate or cancellous screw fixation after obtaining bone mineral density. Biomechanical testing included repetitive plantar to dorsal loading from 0 to 31 N with the 858 Mini Bionix^® (MTS^® Systems Corporation, Eden Prairie, MN, USA). Dorsal angulation of the distal fragment was recorded.

Results

The variable locking plate construct reveals statistically superior results in terms of bending stiffness and dorsal angulation compared to the cancellous screw construct. There was a statistically significant correlation between bone mineral density and maximum tolerated load until construct failure occurred for the screw construct (r = 0.640, p = 0.406).

Conclusion

The results of the present study indicate that variable locking plate fixation shows superior biomechanical results to cancellous screw fixation for proximal chevron osteotomy. Additionally, screw construct failure was related to levels of low bone mineral density. Based on the results of the present study we recommend variable locking plate fixation for proximal chevron osteotomy, especially in osteoporotic bone.     

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.     

Poorly differentiated thyroid carcinoma with sternal invasion. A case report and review of the literature

INTRODUCTION

Surgical resection of poorly differentiated thyroid carcinoma with direct invasion of the sternum has not been previously reported. Only 4 cases of concomitant thyroidectomy and sternal resection and reconstruction for sternal metastases have been published.

PRESENTATION OF CASE

A 66-year-old female with a poorly differentiated thyroid carcinoma and direct sternal invasion underwent total thyroidectomy and resection of the manubrium and both clavicular heads, and chest wall reconstruction with polypropylene mesh and bilateral myocutaneous pectoralis major muscle flaps. Postoperatively, the patient received radioactive iodine ablation. She developed a local recurrence, requiring additional ablation with radioactive iodine and external beam radiation therapy. Although there was no clinical or radiographic evidence of recurrent disease 5-years postoperatively, a possible local recurrence was discovered 4 months later.

DISCUSSION

In previous case reports the sternal metastases were not in continuity with the thyroid tumor. In our patient, however, there was evidence of direct extension between the thyroid tumor and the sternal mass that were connected together with cords of tumor.

CONCLUSION

In our patient with poorly differentiated thyroid carcinoma invading the sternum, total thyroidectomy and resection of the manubrium with sternal reconstruction, combined with adjuvant radioactive iodine ablation and external beam radiation therapy was associated with prolonged survival after 5 years despite a small local recurrence.     

Extracortical plate fixation with new plate inserts and cerclage wires for the treatment of periprosthetic hip fractures

Purpose

Fixation of periprosthetic hip fractures with intracortical anchorage might not be feasible in cases with bulky implants and/or poor bone stock.

Methods

Rotational stability of new plate inserts with extracortical anchorage for cerclage fixation was measured and compared to the stability found using a standard technique in a biomechanical setup using a torsion testing machine. In a synthetic PUR bone model, transverse fractures were fixed distally using screws and proximally by wire cerclages attached to the plates using “new” (extracortical anchorage) or “standard” (intracortical anchorage) plate inserts. Time to fracture consolidation and complications were assessed in a consecutive series of 18 patients (18 female; mean age 81 years, range 55–92) with periprosthetic hip fractures (ten type B1, eight type C-Vancouver) treated with the new device between July 2003 and July 2010.

Results

The “new” device showed a higher rotational stability than the “standard” technique (p < 0.001). Fractures showed radiographic consolidation after 14 ± 5 weeks (mean ± SD) postoperatively in patients. Revision surgery was necessary in four patients, unrelated to the new technique.

Conclusion

In periprosthetic hip fractures in which fixation with intracortical anchorage using conventional means might be difficult due to bulky revision stems and/or poor bone stock, the new device may be an addition to the range of existing implants.     

Effectiveness of a gentamicin impregnated collagen sponge on reducing sternal wound infections following cardiac surgery: a meta-analysis of randomised controlled trials

INTRODUCTION

Gentamicin impregnated collagen sponges are licensed for use after cardiac surgery in over 50 countries but their effectiveness at preventing sternal wound infections (SWIs) remains uncertain. The aim of this meta-analysis was to assess the current evidence for effectiveness of such sponges at preventing SWIs in patients after cardiac surgery.

METHODS

A systematic search of the literature was undertaken and meta-analyses were performed on the results of the identified, eligible studies. Using random effects models, odds ratios (OR) and corresponding 95% confidence intervals (Cl) were calculated for all SWIs and deep SWIs for: a) all participants, and b) participants deemed as high risk.

RESULTS

Three unique randomised controlled trials (published between 2005 and 2010) involving 3,994 participants met the inclusion criteria. There was insufficient evidence of a significant difference between intervention and control groups for all SWIs (all participants: OR: 0.66, 95% Cl: 0.39–1.14; high risk participants: OR: 0.60, 95% Cl: 0.24–1.52). There was insufficient evidence of a significant benefit of the sponge in deep SWIs across all participants (OR: 0.72, 95% Cl: 0.47–1.10) but some evidence of benefit in terms of reducing the incidence of deep SWIs in high risk participants (OR: 0.62, 95% Cl: 0.39–0.98).

CONCLUSIONS

There is insufficient evidence of the effectiveness (or otherwise) of gentamicin impregnated sponges in preventing SWIs following cardiac surgery. However, some evidence does exist that such sponges can reduce the incidence of deep infections in high risk patients.     

Delayed dynamic abdominal wall closure following multi-visceral transplantation

INTRODUCTION

Primary closure of the abdominal wall following intestinal transplantation or multivisceral transplantation could become a challenging problem in a significant number of patients.

PRESENTATION OF CASE

A 38-year-old woman with familial adenomatous polyposis (FAP) underwent a multi-visceral transplantation for short gut syndrome. She subsequently developed acute graft rejection that proved resistant to conventional treatment. She was relisted and underwent re-transplantation along with kidney transplantation. Abdominal wall closure could not be achieved because of the large size of the graft and bowel oedema. The wound was initially managed with laparostomy followed by insertion of the delayed dynamic abdominal closure (DDAC) device (Abdominal Retraction Anchor – ABRA^® system). Continuous dynamic traction to the wound edges resulted in gradual approximation and complete closure of the abdominal wound was achieved within 3 weeks.

DISCUSSION

Successful abdominal closure after multivisceral transplantation or isolated intestinal transplantation often requires biological mesh, vascularised flaps or abdominal wall transplantation. DDAC eliminated the need for a prosthetic mesh or skin graft and provided an excellent cosmetic result. Adjustment of the dynamic traction at the bedside minimised the need for multiple returns to the operating theatre. It resulted in a well-healed linear scar without a hernia.

CONCLUSION

Dynamic traction allows delayed closure of laparotomy resulting in strong and cosmetically sound wound healing with native tissue.     

Locked plate fixation of the comminuted distal fibula: a biomechanical study

Background

The purpose of this study was to compare the biomechanical properties of locked versus nonlocked lateral fibular bridge plating of comminuted, unstable ankle fractures in a mode of catastrophic failure.

Methods

We created comminuted Weber C fractures in 8 paired limbs from fresh cadavers. Fractures were plated with either standard or locked one-third tubular bridge plating techniques. Specimens were biomechanically evaluated by external rotation to failure while subjected to a compressive load approximating body weight. We measured the angle to failure, torque to failure, energy to failure and construct stiffness.

Results

There was no significant difference in construct stiffness or other biomechanical properties between locked and standard one-third tubular plating techniques.

Conclusion

We found no difference in biomechanical properties between locked and standard bridge plating of a comminuted Weber C fibular fracture in a model of catastrophic failure. It is likely that augmentation of fixation with K-wires or trans-tibial screws provides a construct superior to locked bridge plating alone. Further biomechanical and clinical analysis is required to improve understanding of the role of locked plating in ankle fractures and in osteoporotic bone.     

A comparative biomechanical study of proximal femoral nail (InterTAN) and proximal femoral nail antirotation for intertrochanteric fractures

Purpose

The purpose of this study was to compare the biomechanical strength of the cephalomedullary nail InterTAN in cases of intertrochanteric fractures with the commonly used PFNA.

Methods

Sixteen fresh specimens of the proximal femur were used as intertrochanteric fracture models and were fixed using two fixation devices: the new proximal femoral nail (InterTAN) and proximal femoral nail antirotation (PFNA). An intertrochanteric fracture was created in composite bone models. Each specimen was loaded to simulate single leg stance while stiffness, migration (cut out), compressive force across the fracture site, and distal fragment rotation were monitored. The different internal fixation methods were tested by an experimental press analysis.

Results

Results of tests for femoral strength, stiffness, stability, and bearing capacity demonstrated that the biomechanical function of InterTAN was better than that of PFNA (P < 0.05). Compared with the PFNA nail, InterTAN showed increased strength, stiffness, and resistance torque of 30 %, 15 %, and 27 %, respectively.

Conclusion

Comparison of the treatment of intertrochanteric fractures with InterTAN and PFNA internal fixation showed that the InterTAN yielded improvement relative to the PFNA. InterTAN has a firmer and biomechanically superior performance and is therefore an ideal internal fixation method for treating intertrochanteric fractures. Additional research in osteopenic bone is necessary to comprehensively characterize the effects of the design enhancements of these two implants.     

Management of open abdominal wounds with a dynamic fascial closure system

Background

In damage-control surgery, definitive abdominal closure may not be possible for several days or weeks after laparotomy until the patient has stabilized.

Methods

We present 23 patients treated with the Canica ABRA^® dynamic wound closure system that re-approximated open abdomens with silicone elastomers placed transfascially across the wound. This study aimed to assess the results of using this system and to identify risk factors for unsuccessful closure. The system maintains a medially directed force across the wound. A traditional regimen of wound dressing changes was performed.

Results

The dynamic closure system remained in place an average of 48 days and was applied an average of 18 days after the beginning of treatment for the open abdominal wound. Delayed primary fascial closure was achieved in 14 of 23 patients (61%) without further surgery. Six patients (26%) healed with ventral hernias but with a smaller abdominal defect. Two patients (9%) developed enterocutaneous fistulae through the wound that required further surgery. An overall reduction in wound area of 95% was achieved.

Conclusion

This dynamic wound closure technique permitted the delayed primary closure of open abdomens in 61% of cases when treatment was instituted an average of 18 days after initial laparotomy.     

Anterior internal fixator versus a femoral distractor and external fixation for sacroiliac joint compression and single stance gait testing: a mechanical study in synthetic bone

Purpose

The purpose of this study was to evaluate the biomechanical stability and compressive forces across the sacroiliac (SI) joint of an anterior internal fixator compared to the femoral distractor and external fixator for vertically unstable pelvic fractures.

Methods

Five composite pelvises with a simulated APC type III injury fixed with a femoral distractor, external fixator, or anterior internal fixator were tested. A pressure-sensitive film (Tekscan) was placed in the disrupted SI joint recording the magnitude of force. Then, in a single-leg stance model (Instron machine), a load was applied through the sacrum. We recorded displacement at the pubic symphysis and SI joint using high-speed video. Peak load and displacement were measured, and axial stiffness was calculated. Values were compared using a Student’s t-test (p < 0.05).

Results

The SI joint was compressed significantly (p < 0.001) more using the anterior internal fixator (18.9 N) and femoral distractor (18.6 N) than the two-pin external fixator (2.5 N). There was no significant difference between the anterior internal fixator and the femoral distractor in displacement at the SI joint. The pubic symphysis displaced less with the femoral distractor than the anterior internal fixator (5.5 mm vs. 4.1 mm; p < 0.05).

Conclusions

The anterior pedicle screw internal fixator allows for indirect compression across the sacroiliac joint that is superior to two-pin external fixation and comparable to the femoral distractor. The anterior internal fixator may be an option for temporary anterior pelvic fixation in situations where external fixation or the femoral distractor have otherwise been used.     

Floating thumb with double dislocation of carpometacarpal and metacarpo-phalangeal joints

INTRODUCTION

Double dislocations of carpometacarpal and metacarpo-phanlageal joints are rare. We report an unusual case of simultaneous dislocation of both CMC and MCP joints in the thumb.

PRESENTATION OF CASE

A 31 year old male was admitted following a road traffic accident. He was complaining of pain and deformity of right thumb. The X-ray examination revealed simultaneous dislocation of both CMC and MCP joints. He underwent closed manipulative reduction and percutaneous K wire fixation. The wires were removed after six weeks. After a course of physiotherapy he regained full range of pain free movements.

DISCUSSION

The incidence of simultaneous dislocation of both CMC and MCP joints in thumb are associated with high energy injuries. The options of treatment are conservative with cast immobilisation and serial X-rays or operative including closed manipulative reduction and K wire fixation or open reduction and internal fixation.

CONCLUSION

The option of treating this rare injury with closed manipulative reduction and percutaneous K wiring gives excellent and predictable results.     

Biomechanical comparison of the Locking Compression superior anterior clavicle plate with seven and ten hole reconstruction plates in midshaft clavicle fracture stabilisation

Purpose

The purpose of this study was to characterise the biomechanical properties of the seven hole superior anterior clavicle LCP (locking compression plate) and to compare these with the properties of commonly applied implants used for the stabilisation of clavicular midshaft fractures such as the locking 7- and ten hole reconstruction plate.

Methods

Twenty-four synthetic clavicles were used. A transverse midshaft fracture was induced. The clavicles were fixed with angle stable clavicle LCPs, seven hole and ten hole reconstruction plates (n = 8 each). Twenty cycles of axial compression and torsion were performed for each sample, which was followed by 1,000 cycles of three point bending and ultimately bending to failure. Axial, torsional and cantilever bending stiffness were calculated from the data recorded.

Results

The clavicle LCP showed the highest overall stiffness compared to the seven and ten hole reconstruction plate. Significantly higher stiffness values were found for axial compression and external rotation. In the load-to-failure tests, the ten hole reconstruction plate especially showed early signs of plastic deformation, which might account for early plate insufficiency so frequently observed clinically.

Conclusion

The results indicate that the clavicle LCP, as compared to the reconstruction plates, leads to superior biomechanical stability in the treatment of midshaft clavicle fractures.     

Anterior cruciate ligament deficiency leads to early instability of scaffold for cartilage regeneration: a controlled laboratory ex-vivo study

Purpose

The affect of anterior cruciate ligament (ACL) integrity on the early postoperative stability of a collagen type-I gel scaffold was investigated. The value of fibrin glue for graft fixation in ACL deficient porcine knees over a simulated early postoperative period was also studied.

Methods

Full-thickness articular cartilage defects (11 × 6 mm) were created on the medial femoral condyle of 80 porcine knees. The ACL was left intact or completely transected in each of 40 knees. Gel plugs were tested in each group: press-fitting only in 20 specimens and press-fitting plus fibrin glue in 20 specimens. Each knee underwent 2,000 cycles in a validated ex-vivo continuous passive motion model.

Results

Press-fit-only fixation grafts in knee specimens with an intact ACL showed significantly superior stability than that in ACL deficient knees (p = 0.01). In ACL deficient knees, grafts fixed with press-fitting plus fibrin glue showed significantly superior stability than those using press-fit only fixation (p = 0.01). Press-fitting plus fibrin glue fixation showed no significant differences in worn surface area between knee specimens with intact and deficient ACL.

Conclusions

ACL deficiency led to early scaffold instability in an ex-vivo porcine knee model. Fibrin glue in ACL deficient knees led to additional graft stability. These findings indicated that cartilage regenerative techniques may give optimum results in ACL intact knees.     

Post-facelift flap necrosis treatment using charged polystyrene microspheres

BACKGROUND:

Flap necrosis following facial rhytidectomy constitutes a vexing and grievous complication to the patient and the surgeon. Treatment modalities that can expedite wound healing and re-epithelialization rates are highly desired.

OBJECTIVES:

To assess wound healing and re-epithelialization rates of open wounds following postrhytidectomy flap necrosis treated with commercially available charged polystyrene microspheres (Polyheal-1, Polyheal Ltd, Israel).

METHODS:

Flap necrosis following rhytidectomy with open wounds in three female patients were treated using dressings soaked with Polyheal-1. Wound closure rates were documented.

RESULTS:

The wounds demonstrated both accelerated granulation tissue formation and rapid re-epithelialization rates. No complications or side effects were encountered.

CONCLUSIONS:

Charged polystyrene microspheres may offer a new and efficacious way to treat open wounds due to flap necrosis following facial rhytidectomy. Further research with larger patient numbers is still needed to verify these findings.