4. Results

of a partial or complete annular ring. When resecting the mitral valve, the posteroinferior zone of the mitral annulus should be inspected because myocardial ring abscess usually occurs in this location [39, 40]. When left atrioventricular discontinuity is present in mitral valve IE, a small variation of the usual valve replacement can be used. After thorough debridement of the affected tissue in the mitral ring, interrupted horizontal mattress sutures are anchored with felt or autologous pericardium pledgets to the ventricular aspect of the mitral annulus, brought up through the left atrial aspect and then through the prosthetic sewing ring. Deep bytes are performed [37]. When extensive ring abscess is present (Figure 4), a different approach is done. The atrioventricular discontinuity is reconstructed using an autologous or bovine pericardial patch. The ventricular aspect is anchored to the myocardium and endocardium using deep bytes of continuous 3-0 or 4-0 polypropylene suture. The superior aspect of this patch is anchored to the left atrial side with a continuous suture (Figure 5). The prosthesis is anchored to the ventricular aspect of the suture line using interrupted horizontal mattress sutures supported with felts pledgets (Figure 6) [37]. Using antibiotic, antiseptic solutions (e.g., povidone-iodine), or antifungal agents to impregnate the prosthesis and the affected area has been described to help in the management of this entity [41–43]. Mitral valve repair for IE continues to be challenging and much less commonly performed than valve replacement [44]. Repairing tissues that may be infected in the acute stages and the durability of repairing inflamed tissues are the main concerns influencing the decision [45–47]. Several studies have reported excellent results for mitral valve

Figure 4. Infective endocarditis with ring abscess compromising the posterior leaflet of mitral valve.

repair in IE [48–51].

92 Advanced Concepts in Endocarditis

Hospital mortality for valve operations in patients with IE varies widely (4–30%) [52–57]. This variation can be due to several factors, especially the difference in risk between the acute phase of IE and the healed stage. A study from Richardson reported a mortality of 14% in surgically treated patients versus 44% in those medically treated. Operative mortality was affected by urgency of operation.Mortality for elective operations (next convenient day), was 5%, for urgent operations (next day), 16% and for emergent operations in patients with cardiogenic shock (immediately), 33% [58].

Freedom from reoperation is higher when the mitral valve is involved (compared with the aortic valve) probably for less annular involvement. In a series from Brigham and Women's Hospital (Boston) reporting freedom from reoperation for mitral valve IE, the results found 92 and 62% at 5 and 10 years for acute endocarditis and 94% and 84% for healed endocarditis (p = 0.7), respectively [59]. A serious complication after valve replacement for IE is a new or worsening neurologic deficit. Friable vegetation may dislodge and cause CNS deficits. Moreover, an existing CNS deficit is aggravated by operation. A study from university of Illinois found evidence of cerebral septic emboli in 42% of patients who underwent valve replacement for IE. Complications included postoperative strokes in 6%, brain abscesses in 2%, and seizures in 1% [60].

• IE caused by multiresistant organisms (e.g., methicillin-resistant S. aureus or vancomycin-resistant enterococci) and

Surgical Management of Mitral Valve Endocarditis http://dx.doi.org/10.5772/intechopen.73679 95

• Late prosthetic valve endocarditis with heart failure caused by prosthetic dehiscence or obstruction or other

Surgery should be performed immediately, irrespective of antibiotic therapy, in patients with persistent pulmonary edema or cardiogenic shock. If congestive heart failure disappears with medical therapy and there are no other surgical indications, intervention can be postponed to allow a period of days or weeks of antibiotic treatment under careful clinical and echocardiographic observation. In patients with well-tolerated severe valvular regurgitation or prosthetic dehiscence and no other reasons for surgery, conservative therapy under careful clinical and echocardiographic observation is recommended with consideration of deferred surgery after resolution of the infection, depending upon tolerance of the

In all cases, surgery for the prevention of embolism must be performed very early since embolic risk is highest during the

Surgery is contraindicated for at least 1 month after intracranial hemorrhage unless neurosurgical or endovascular

• Native (aortic or mitral) or prosthetic valve endocarditis and severe congestive heart failure or cardiogenic shock

• Native valve endocarditis with persisting congestive heart failure, signs of poor hemodynamic tolerance, or abscess • Prosthetic valve endocarditis with persisting congestive heart failure, signs of poor hemodynamic tolerance, or

• Severe aortic or mitral regurgitation with congestive heart failure and good response to medical therapy • Prosthetic valve endocarditis with valvular dehiscence or congestive heart failure and good response to medical

rare infections caused by Gram-negative bacteria

• Q fever IE and other relative indications for intervention

• Virtually all cases of early prosthetic valve endocarditis

intervention can be performed to reduce bleeding risk. Adapted from ACC/AHA 2014 Guidelines [8].

Table 3. Indications for surgery for infective endocarditis.

• Severe prosthetic dysfunction (dehiscence or obstruction) • Fistula into a cardiac chamber or the pericardial space

• Large vegetation (10 mm) with other predictors of a complicated course • Very large vegetation (15 mm), especially if conservative surgery is available • Large abscess and/or periannular involvement with uncontrolled infection

• Persisting infection when extracardiac focus has been excluded

• Prosthetic valve endocarditis caused by staphylococci or Gram-negative organisms

• Virtually all cases of prosthetic valve endocarditis caused by S. aureus

• Pseudomonas aeruginosa IE

Prosthetic valve endocarditis

indications for surgery

• Fungal IE

\*

‡

valve lesion. †

first days of therapy.

Emergency surgery (within 24 h)

Urgent surgery (within days)

• Acute valvular regurgitation

• Large vegetation (10 mm) with an embolic event

Early elective surgery (during the in-hospital stay)

• Presence of abscess or periannular extension

Adapted from Prendergast et al. [26].

Table 4. Timing of surgery.

• Fungal or other infections resistant to medical cure

caused by:

abscess

therapy
