Spontaneous Right Ventricular Disruption Following Treatment of Sternal Infection

2011

Int J Colorectal Dis

PurposeHigher closure rates of the open abdomen have been reported with negative pressure wound therapy (NPWT) compared with other wound therapy techniques. However, the method has occasionally been associated with increased development of intestinal fistulae. The present study measures microvascular blood flow in the intestinal wall and the omentum before and during NPWT.MethodsSix pigs underwent midline incision and application of NPWT to the open abdomen. The microvascular blood flow in the underlying intestinal loop wall and the omentum was recorded before and after the application of NPWT of −50, −70, −100, −120, −150, and −170 mmHg respectively, using laser Doppler velocimetry.ResultsA significant decrease in microvascular blood flow was seen in the intestinal wall during application of all negative pressures levels. The blood flow was 2.7 (±0.2) Perfusion Units (PU) before and 2.0 (±0.2) PU (*p < 0.05) after application of −50 mmHg, and 3.6 (±0.6) PU before and 1.5 (±0.2) PU (**p < 0.01) after application of −170 mmHg.ConclusionsIn the present study, we show that negative pressures between −50 and −170 mmHg induce a significant decrease in the microvascular blood flow in the intestinal wall. The decrease in blood flow increased with the amount of negative pressure applied. One can only speculate that a longstanding decreased blood flow in the intestinal wall may induce ischemia and secondary necrosis in the intestinal wall, which, theoretically, could promote the development of intestinal fistulae. We believe that NPWT of the open abdomen is a very effective treatment but could probably be improved.

Section: Discussionmentioning

confidence: 99%

Microvascular blood flow response in the intestinal wall and the omentum during negative wound pressure therapy of the open abdomen

Hlebowicz

Hansson

2011

Int J Colorectal Dis

“…One of the major advantages of applying NPWT to sternotomy wounds is that it stabilizes the sternum, which facilitates respiration and allows early mobilization [5,6]. However, complications associated with bleeding and heart rupture with lethal outcome have been reported in several studies [2,4,12]. The insertion of a rigid barrier between the heart and the sharp edges of the sternum has been suggested to prevent such complications [10].…”

Section: Discussionmentioning

confidence: 99%

“…There are, however, increasing numbers of reports of deaths and serious complications associated with the use of NPWT due to heart rupture, lung rupture, bypass graft bleeding and death; the incidence being 4 to 7% of all patients treated for poststernotomy mediastinitis with NPWT after cardiac surgery [2-4]. In November 2009, the FDA filed an alert, and the importance of protecting exposed organs during NPWT and this issue has also been emphasized in the international scientific literature [5-8].…”

Section: Introductionmentioning

confidence: 99%

Sternum wound contraction and distension during negative pressure wound therapy when using a rigid disc to prevent heart and lung rupture

Ingemansson

Malmsjö

2011

J Cardiothorac Surg

BackgroundThere are increasing reports of deaths and serious complications associated with the use of negative pressure wound therapy (NPWT), of which right ventricular heart rupture is the most devastating. The use of a rigid barrier has been suggested to offer protection against this lethal complication by preventing the heart from being drawn up against the sharp edges of the sternum. The aim of the present study was to determine whether a rigid barrier can be safely inserted over the heart with regard to the sternum wound edge movement.MethodsSternotomy wounds were created in eight pigs. The wounds were treated with NPWT at -40, -70, -120 and -170 mmHg in the presence and absence of a rigid barrier between the heart and the edges of the sternum. Wound contraction upon NPWT application, and wound distension under mechanical traction to draw apart the edges of the sternotomy were evaluated.ResultsWound contraction resulting from NPWT was similar with and without the rigid barrier. When mechanical traction was applied to a NPWT treated sternum wound, the sternal edges were pulled apart. Wound distension upon traction was similar in the presence and absence of a the rigid barrier during NPWT.ConclusionsA rigid barrier can safely be inserted between the heart and the edges of the sternum to protect the heart and lungs from rupture during NPWT. The sternum wound edge is stabilized equally well with as without the rigid barrier during NPWT.

“…There are, however, increasing numbers of reports of deaths and serious complications associated with the use of NPWT, where right ventricle rupture and bypass graft rupture resulting in death are the most devastating complications; the incidence being 4 to 7% of the patients treated for deep sternal wound infection with NPWT after cardiac surgery [7-9]. We have previously described the cause of heart rupture in pigs using magnetic resonance imaging [10,11].…”

Section: Introductionmentioning

confidence: 99%

A rigid barrier between the heart and sternum protects the heart and lungs against rupture during negative pressure wound therapy

Ingemansson

Malmsjö

2011

J Cardiothorac Surg

ObjectivesRight ventricular heart rupture is a devastating complication associated with negative pressure wound therapy (NPWT) in cardiac surgery. The use of a rigid barrier has been suggested to offer protection against this lethal complication, by preventing the heart from being drawn up and damaged by the sharp edges of the sternum. The aim of the present study was to investigate whether a rigid barrier protects the heart and lungs against injury during NPWT.MethodsSixteen pigs underwent median sternotomy followed by NPWT at -120 mmHg for 24 hours, in the absence (eight pigs) or presence (eight pigs) of a rigid plastic disc between the heart and the sternal edges. The macroscopic appearance of the heart and lungs was inspected after 12 and 24 hours of NPWT.ResultsAfter 24 hours of NPWT at -120 mmHg the area of epicardial petechial bleeding was 11.90 ± 1.10 cm2 when no protective disc was used, and 1.15 ± 0.19 cm2 when using the disc (p < 0.001). Heart rupture was observed in three of the eight animals treated with NPWT without the disc. Lung rupture was observed in two of the animals, and lung contusion and emphysema were seen in all animals treated with NPWT without the rigid disc. No injury to the heart or lungs was observed in the group of animals treated with NPWT using the rigid disc.ConclusionInserting a rigid barrier between the heart and the sternum edges offers protection against heart rupture and lung injury during NPWT.