Indications and Results of Sternal Allograft Transplantation: Learning From a Worldwide Experience.

BACKGROUND: Reconstruction of the anterior chest wall defect after sternectomy is a challenge for cardiothoracic surgeons. In 2010, the Padua group published the first case of cadaveric sternum transplantation after sternectomy. This multicenter study reports the clinical indications and early and long-term results of sternal chondral allograft transplantation. METHODS: This is a retrospective multicenter study from 7 academic centers. We collected demographic data, surgical indications, technical details, and early postoperative results. The complications, long-term stability, and tolerance of the allografts were also analyzed. RESULTS: Between January 2008 and December 2019, 58 patients underwent sternectomy followed by reconstruction using cadaveric-cryopreserved sternochondral allografts. Thirty-two patients were male, median age 63.5 years (interquartile range, 50-72 years). Indications for sternectomy were secondary sternal tumors (n = 13), primary sternal tumors (n = 15), and nonneoplastic disease (n = 30). Thirty patients underwent total sternectomy, 16 lower-body sternectomy, and 12 upper-body manubrium resection. The 30-day mortality was 5%; overall morbidity was 31%. Six early reoperations were necessary because of bleeding (n = 1), titanium plate dislocation (n = 1), and resuture of the skin in the lower part of the incision (n = 4). Overall, 5-year survival was 74%. In all the survived patients, the reconstructions were stable and free from mechanical or infective complications. CONCLUSIONS: The main indications for sternal allograft implantation were complex poststernotomy dehiscence followed by primary or secondary tumor involvement of the sternum. The collected results demonstrate that sternochondral allograft transplantation is a safe and effective method in reconstructing the anterior chest wall after sternectomy. Further studies to demonstrate the integration of the bone grafts into the patients' sternal wall will be made.

Human native endocarditis caused by Streptococcus canis-a case report.

We report a very rare case of Streptococcus canis native infective endocarditis in a 73-year-old woman living in close contact with her dog. Her echocardiography showed large calcifications in the mitral annulus, massive regurgitation below the posterior leaflet, and adjacent vegetation. Blood culture was positive for Streptococcus Lancefield group G. A coronary artery bypass and mitral valve replacement had to be done. Streptococcus canis was detected in a heart valve using a broad range PCR followed by 16S rRNA and confirmed by tuf gene sequencing, while tissue culture remained negative. The patient was not bitten by her dog nor did she have comorbidities or skin ulcers. She fully recovered.

Electrospun vascular grafts fabricated from poly(L-lactide-co-ε-caprolactone) used as a bypass for the rabbit carotid artery.

The study involved the electrospinning of the copolymer poly(L-lactide-co-ε-caprolactone) (PLCL) into tubular grafts. The subsequent material characterization, including micro-computed tomography analysis, revealed a level of porosity of around 70%, with pore sizes of 9.34 ± 0.19 µm and fiber diameters of 5.58 ± 0.10 µm. Unlike fibrous polycaprolactone, the electrospun PLCL copolymer promoted fibroblast and endothelial cell adhesion and proliferation in vitro. Moreover, the regeneration of the vessel wall was detected following implantation and, after six months, the endothelialization of the lumen and the infiltration of arranged smooth muscle cells producing collagen was observed. However, the degradation rate was found to be accelerated in the rabbit animal model. The study was conducted under conditions that reflected the clinical requirements-the prostheses were sutured in the end-to-side fashion and the long-term end point of prosthesis healing was assessed. The regeneration of the vessel wall in terms of endothelialization, smooth cell infiltration and the presence of collagen fibers was observed after six months in vivo. A part of the grafts failed due to the rapid degradation rate of the PLCL copolymer.

The effect of continuous elimination methods on the hemostatic profile of a cardiac surgery patient monitored using thromboelastography.

INTRODUCTION: This work is focused on mapping issues of hemostasis in patients during continuous renal replacement therapy, or the possible impact of the use of anticoagulants. METHODS: The study included 30 consecutive patients requiring continuous renal replacement therapy following cardiac surgery in the period of 2009 to 2012. Patients were placed into 2 branches according to the selected method of anticoagulation (regional citrate anticoagulation-RCA, unfractionated heparin UFH). According to the given scheme (t1-t7) thromboelastography and laboratory testing related to the testing of blood clotting during continuous renal replacement therapy were performed. RESULTS: The average lifespan of a hemofilter during continuous renal replacement is 58.13 ± 9.968 hours. During continuous renal replacement therapy there are significant changes in the initiation of coagulation according to thromboelastographic parameters (R, K, alpha angle) in both branches of anticoagulation. The maximum image changes in hemostasis occur around 24 hours (t4) from the start of the procedure. The nature of the changes is the procoagulant activity in these parameters. In the branch of regional citrate anticoagulation a higher value of functional fibrinogen is apparent. There was no significant difference in the activation of native blood between UFH and RCA. CONCLUSIONS: During continuous renal replacement therapy significant changes occur in the thromboelastographic image and the laboratory parameters in blood clotting. The nature of the change is the procoagulant activity. The question remains about the complexity of the changes that TEG is not able to detect, especially in the cellular area.

Delayed revascularization following complete transection of left anterior descending artery after a stab wound.

INTRODUCTION: Penetrating heart injury as a consequence of a stab wound is usually considered fatal. Nevertheless, there are rare lucky cases with mild symptoms which deserve clinical suspicion and proper management. PRESENTATION OF CASE: We report a penetrating cardiac trauma with left anterior descending coronary artery transection after a stab wound. Successful revascularization without cardiopulmonary bypass support was performed. DISCUSSION: Coronary artery injuries after penetrating cardiac trauma are mostly fatal. The standard approach has traditionally been coronary artery ligation with serious morbidity. We report a case of complete coronary artery transection with delayed revascularization validating the safety of off-pump approach. We add a short literature review of the management of traumatic coronary artery injury. CONCLUSION: This adds to the world literature on coronary artery trauma with successful off-pump revascularization. Coronary artery transection stab-wound victims can have only mild symptoms. Slightest intimation of heart injury should provoke proper clinical examination and management.

Metal splinter ejected by circular saw into the left ventricle.

We report a case of a metal splinter ejected by a circular saw tooth from a wooden board into the left ventricle of the heart. A 35-year old man was admitted second day after accident attributed to work complaining about general weakness. Only a small non-bleeding wound was found near his sternum. CT scan showed a metal wire entrapped inside his heart. Successful removal was done during surgery.

Pericardial tamponade: a rare complication of sternal bone marrow biopsy.

Injury of the heart with concomitant pericardial tamponade as a result of sternal bone marrow biopsy is rare. An 80-year-old man was admitted with dehydration and non-specified abdominal pain to the regional hospital. Sternal aspiration biopsy was performed because of anemia and thrombocytopenia. Later on, because of the back pain, general weakness and blood pressure drop, an echocardiography examination was indicated. Pericardial fluid collection was found. Anticipated ascending aortic dissection was excluded on computed tomography scan, but pericardial fluid collection was confirmed. Transfer to our cardiac surgical facility ensued. Limited heart tamponade was affirmed on echocardiography and surgery was immediately indicated. Blood effusion was found in upper mediastinal fat tissue and 300 mL of blood were evacuated from opened pericardial space. Stab wound by sternal biopsy needle at the upper part of ascending aorta was repaired by pledgeted suture. Postoperative course was uneventful.

Peripheral tissue oxygenation during standard CPB and miniaturized CPB (direct oxymetric tissue perfusion monitoring study).

AIM: The aim of this study was to compare the impact of standard cardiopulmonary bypass (CPB) with mini CPB on peripheral tissue perfusion. METHODS: 24 patients with ischemic heart disease scheduled for CPB were randomised to two groups: Group A (12 patients, standard CPB) and Group B (12 patients, mini CPB). Oxygen tension was measured with an optical multiparametric sensor inserted into the patient's deltoid muscle. RESULTS: Lower priming in Group B (870 ± 221 mL) vs. Group A (1502 ± 48 mL) and significantly reduced hemodilution during mini CPB (Group B 25.3 ± 1.1% vs. Group A 30.1 ± 2.3%) were recorded. Higher and continuous blood flow during perfusion was analysed in Group A (4.58 ± 0.34 L.min(-1)) and lower than calculated blood flow was found in Group B (3.49 ± 0.51 L.min(-1) vs. 4.66 ± 0.38 L.min(-1)). There was a direct correlation between mean arterial pressure (MAP) and ptO2 in Group A during CPB and a direct correlation between pump blood flow and MAP during CPB in Group B. Higher levels of ptO2 during CPB and surgery after CPB in comparison with initial levels were found in Group B. Decreased ptO2 levels after surgery were found in both groups. CONCLUSION: Mini CPB enables perfusion with a relatively low flow. The results of this study suggest that a flow decrease in mini CPB is well tolerated by the organism.

Endoscopic radial artery harvesting for coronary artery bypass grafting. A single center evolving experience.

AIM: We sought to evaluate our experience with endoscopic radial artery harvesting for coronary artery bypass grafting (CABG). METHODS: From October 2005 to June 2010, 50 patients who underwent endoscopic radial artery harvesting for an elective CABG were prospectively assessed for harvesting characteristics, complications, postoperative and mid-term outcomes. RESULTS: There were 34 (68%) males and 16 (32%) females, average age 60.8 ± 9.2 years. All but two RA grafts (96%) were successfully harvested endoscopically. Mean harvesting time was 46.2 ± 9.3 min and mean length of harvested grafts was 23.4 ± 2.2 cm. In the post-operative period there were no wound-healing complications; residual forearm edema was recorded in 6 patients (12%) and peripheral neuropathy in 4 patients (8%). At 3 months after the surgery, peripheral neuropathy and residual edema persisted in 2 patients (4%). A significant drop of overall harvesting time (56.2 ± 18.6 vs. 38.6 ± 8.6 min, P<0.05) and forearm ischemia time (41.8 ± 12.7 vs. 24.2 ± 3.2 min, P<0.01) was found between first and last ten cases in the group. CONCLUSION: Endoscopic radial artery harvesting was associated with low risk of post-harvesting complications and most of these disappeared within a 3 months follow-up. However, there was a significant learning curve.

Pectoral muscle flap with V-Y skin paddle for covering sternal defects.

Deep sternal wound infection (DSWI) after a cardiac operation is a rare but serious complication associated with significant morbidity and mortality. It can lead to wound dehiscence with sternal osteomyelitis and both bony and soft tissue residual defects. When the infection is eradicated, reconstruction of the thoracic wall remains the main challenge. Tissue used for covering the defect must be well nourished and sutures must be tension free. We present our unique modification of the method using the pectoral muscle axial flap with a V-Y skin paddle.

Comparison of functional fibrinogen assessment using thromboelastography with the standard von Clauss method.

AIM: To compare assessment of fibrinogen by thromboelastography with the standard von Clauss method. METHODS: Observational prospective study. RESULTS: Thromboelastography provides direct and complex evaluation of the entire coagulation cascade based upon changes in blood viscosity. It affects both platelets and plasma components. New application of this method measures fibrinogen contribution to coagulation as opposed to fibrinogen antigen levels measured by immunoassay. Paired samples from 117 patients before cardiopulmonary bypass were compared. A moderate correlation was found between fibrinogen and functional fibrinogen with a Spearman correlation coefficient of 0.476. CONCLUSION: The functional fibrinogen test is a valid point-of-care method for fibrinogen assay with a moderate correlation to the standard method.

The effect of conventional and mini-invasive cardiopulmonary bypass on neutrophil activation in patients undergoing coronary artery bypass grafting.

Interleukin-10 (IL-10) is considered to be a cytokine with potent anti-inflammatory properties, which have been previously linked to increased incidence of sepsis. The level of IL-10 is elevated by cardiac surgery when cardiopulmonary bypass (CPB) and methylprednisolone are used. In our study, we compare the level of IL-10, IL-10 Receptor (IL-10R), and percentage of neutrophils between two groups of cardiac surgical patients undergoing Coronary Artery Bypass Grafting, both of which were not given methylprednisolone. The first group was operated with conventional CPB, while the second group was operated with minimally invasive CPB (mini-CPB). We detected enhanced level of IL-10 during surgery and at the end of surgery in both groups of patients. While no correlation between IL-10 and IL10R was found, IL-10 was positively correlated with increased percentage of neutrophils at the time points when the level of IL-10 peaked.

Use of allogenous bone graft and osteosynthetic stabilization in treatment of massive post-sternotomy defects.

Thoracic stabilization using transverse plate fixation represents a modern and safe method of sternal dehiscence treatment. However, it still remains difficult to apply in cases of massive loss of bone tissue of the chest wall. An unsatisfactory stability of thorax often results in severe respiratory insufficiency, and also affects healing of soft tissue closure while increasing the risk of development of chronic fistulas and other dehiscences. In the reported case, we opted for a unique treatment of massive post-sternotomy defect using an allogenous bone graft of calva. Transverse titanium plates were applied to achieve stabilization of bone grafts and chest wall.

Predictors of failure following restrictive annuloplasty for chronic ischemic mitral regurgitation.

AIM OF THE STUDY: We sought to determine the results of restrictive annuloplasty for chronic ischemic mitral regurgitation. METHODS: Hospital outcome and serial clinical and echocardiographic (preoperative, discharge, 3 months, 12 months, 24 months) follow-up assessments were analyzed in 87 consecutive patients with chronic ischemic mitral regurgitation having coronary artery bypass grafting. Persistent/recurrent mitral regurgitation was defined by grade ≥2 at discharge/during follow-up. RESULTS: Hospital mortality was 5.7% and persistence of regurgitation was present in 8.4%. Mean follow-up was 24.4 ± 1.7 months and recurrent mitral regurgitation was observed in 32.4% patients. In multivariate analysis only anterior leaflet angle remained an independent predictive factor for regurgitation recurrence with cutoff 27° (sensitivity of 67% and specificity of 76%, p = 0.04). CONCLUSION: There is high occurrence of early and delayed restrictive annuloplasty failure, particularly in patients with increased anterior leaflet tethering.

Persistent and recurrent ischemic mitral regurgitation.

BACKGROUND: Ischemic mitral regurgitation (IMR) is a consequence of coronary artery disease and the main underlying mechanism is augmented leaflet tethering due to outward displacement of the papillary muscles. Although mitral annuloplasty combined with coronary revascularization is usually effective in the treatment of IMR, occasionally the regurgitation can persist or recur and this can affect patient prognosis. METHODS: We searched Medline and Google scholar database for articles published since 1996 to June 2009. Search terms included ischemic mitral regurgitation, recurrent mitral regurgitation, persistent mitral regurgitation and annuloplasty failure. CONCLUSION: This article reviews current knowledge about IMR, the reasons and mechanisms of persistent and recurrent mitral regurgitation. We review clinic and echocardiographic predictive factors associated with persistence a recurrence of mitral regurgitation after annuloplasty.

Pathophysiological aspects of cardiotomy suction usage.

Cardiotomy suction is used for preservation of autologous blood during on-pump cardiac surgery at present. Controversially, the exclusion of cardiotomy suction in some types of operations (coronary artery bypass surgery) is not necessarily associated with an increased transfusion requirement. On the other hand, the use of cardiotomy suction causes an amplification of systemic inflammatory response and a resulting coagulopathy, as well as exacerbation of the microembolic load and hemolysis. This leads to a tendency towards increased blood loss, transfusion requirement and organ dysfunction. On the basis of these facts, it is appropriate to reconsider routine use of cardiotomy suction in on-pump coronary artery surgery.

Serum level of sCD163, a soluble receptor for hemoglobin, is influenced by cardiac surgery.

BACKGROUND: The scavenger receptor for complexes hemoglobin-haptoglobin (CD163), which is expressed on monocytes/ macrophages, is shed to the body fluids in a soluble form (sCD163). OBJECTIVES: To evaluate the dynamics of sCD163 in the blood of patients undergoing cardiac surgery. PATIENTS AND METHODS: Sixty-one adult patients who underwent coronary artery bypass grafting (CABG) were enrolled in the study. They were assigned to undergo CABG using either cardiopulmonary bypass (CPB), "on-pump", (22 patients), modified CPB, mini "on-pump", (17 patients) or without CPB, "off-pump", (22 patients) surgery. Serum levels of sCD163 in venous blood samples taken before and after surgery, and during an early postoperative period, were evaluated by Macro 163(TM) diagnostic kit (IQ Products, Groningen, NL). RESULTS: Compared to the preoperative levels ("on-pump"; 344 ng/mL, "off-pump"; 314.5 ng/mL, mini-invasive "on-pump"; 336.5 ng/mL) serum levels were elevated at the finish of surgery, reaching maximum at the 1(st) postoperative day ("onpump"; 658 ng/mL; p<0.05, "off-pump"; 810.5 ng/mL; p<0.01; mini-invasive "on-pump"; 663 ng/mL; non-significant).No significant differences regarding the serum levels of sCD163 between different surgical approaches were found. CONCLUSION: Serum level of sCD163 scavenger molecule for hemoglobin is elevated at the end of surgery and at the 1(st) postoperative day, being little influenced by cardiopulmonary bypass.