Perioperative neuromonitoring during thoracoabdominal aortic aneurysm open repair: a systematic review.

OBJECTIVES: While open surgical repair remains the gold standard for thoracoabdominal aortic aneurysm (TAAA) treatment, there is still no consensus regarding perioperative neuromonitoring technique for prevention of spinal cord ischaemia. METHODS: In this systematic review, we aimed to explore the effects and practices of neuromonitoring during the open TAAA repair. A systematic literature search in PubMed, Embase via Ovid, Cochrane library and ClinicalTrialsGov until December 2022 was performed. RESULTS: A total of 535 studies were identified from the literature search, of which 27 studies including a total of 3130 patients met the eligibility criteria. Most studies (21 out of 27, 78%) investigated the feasibility of motor-evoked potentials (MEP), while 15 analysed somatosensory-evoked potentials (SSEP) and 2 studies analysed near-infrared spectroscopy during open TAAA repair. CONCLUSIONS: Current literature suggest that rates of postoperative spinal cord ischaemia can be kept at low levels after open TAAA repair with the adequate precautions and perioperative manoeuvres. Neuromonitoring with MEP provides the surgeon objective criteria to direct selective intercostal reconstruction or other protective anaesthetic and surgical manoeuvres. Simultaneous monitoring of MEP and SSEP is a reliable method that can rapidly detect important findings and direct adequate protective manoeuvres during open TAAA repair.

Factors associated with long-term outcomes in adult congenital heart disease patients with infective endocarditis: a 16-year tertiary single-centre experience.

OBJECTIVES: Studies concerning factors associated with long-term outcomes in adult congenital heart disease (ACHD) patients after infective endocarditis (IE) are scarce, while IE-related mortality in these patients remains a burden. We evaluated the factors associated with long-term survival in ACHD patients admitted for IE. METHODS: We performed a retrospective single-centre study of all ACHD patients admitted for IE to a tertiary cardiothoracic centre between 1999 and 2015. Underlying ACHD, detailed echocardiographic and clinical data, surgical treatment and long-term follow-up were analysed. RESULTS: We identified 151 ACHD patients admitted due to 176 episodes IE with 30-day, 6-month and 1-, 5- and 10-year survival of 95.4%, 92.7%, 92.7%, 84.7% and 75.6%, respectively. In a multivariable analysis, adjusted estimated probability of death was consistently higher after an IE episode among patients with complex as compared to simple/moderate ACHD: 10.6% vs 2.4% at 30 days, 15.0% vs 3.4% at 6 months and 1 year, 30.4% vs 7.8% at 5 years and 44.9% vs 13.1% at 10 years. Risk of death was higher among patients with prosthetic valve in comparison with those without (risk ratios 1.73-1.92). Surgical treatment was required in 76 (43.2%) episodes with 30-day mortality of 3.9%. Risk of death appeared to be lower than in the conservatively treated subgroup (risk ratios 0.71-0.78). CONCLUSIONS: We demonstrated satisfactory long-term survival in ACHD patients who were treated for IE in a tertiary cardiothoracic centre. Early mortality tended to be lower in the surgically treated subgroup. Factors negatively associated with long-term survival were complex ACHD and presence of prosthetic valve.

Comparing mid-term outcomes of Cox-Maze procedure and pulmonary vein isolation for atrial fibrillation after concomitant mitral valve surgery: A systematic review.

BACKGROUND: Although concomitant pulmonary vein isolation (PVI) is used more frequently than the Cox-Maze procedure, which is currently the gold standard treatment for atrial fibrillation (AF), data on the comparative effectiveness of the two procedures after concomitant mitral valve (MV) surgery are still limited. OBJECTIVE: We conducted a systematic review to identify randomized controlled trials (RCTs) and observational studies comparing the mid-term mortality and recurrence of AF after concomitant Cox-Maze and PVI in patients with AF undergoing MV surgery based on 12-month follow-up. METHODS: Medline, EMBASE databases, and the Cochrane Library were searched from 1987 up to March 2022 for studies comparing concomitant Cox-Maze and PVI. Additionally, a meta-analysis of RCTs was performed to compare the mid-term clinical outcomes between these two surgical ablation techniques. RESULTS: Three RCTs and three observational studies meeting the inclusion criteria were included in this systematic review with 790 patients in total (532 concomitant Cox-Maze and 258 PVI during MV surgery). Most studies reported that the concomitant Cox-Maze procedure was associated with higher freedom from AF at 12-month follow-up than PVI. Regarding AF recurrence, estimates pooled across the three RCTs indicated large heterogeneity and high uncertainty. In the largest and highest quality RCT, 12-month AF recurrence was higher in the PVI arm (risk ratio = 1.58, 95% CI: 0.91-2.73). In two out of three higher-quality observational studies, 12-month AF recurrence was higher in PVI than in the Cox-Maze arm (estimated adjusted probabilities 11% vs. 8% and 35% vs. 17%, respectively). RCTs demonstrated comparable 12-month mortality between concomitant Cox-Maze and PVI, while observational studies demonstrated the survival benefit of Cox-Maze. CONCLUSIONS: Concomitant Cox-Maze in AF patients undergoing MV surgery is associated with better mid-term freedom from AF when compared to PVI with comparable mid-term survival. Large observational studies suggest that there might be a mid-term survival benefit among patients after concomitant Cox-Maze. Further large RCTs with longer standardized follow-up are required to clarify the benefits of concomitant Cox-Maze in AF patients during MV surgery.

Fiftieth anniversary of the first heart transplantation in Switzerland in the context of the worldwide history of heart transplantation.

On 3 December 1967, Christiaan Barnard performed the first heart transplantation in the world at Groote Schuur Hospital in Cape Town, South Africa. In the succeeding months, heart transplantations in the USA, Asia and Europe followed. On 14 April 1969, Åke Senning successfully accomplished the first heart transplantation in Switzerland at the former Cantonal Hospital in Zurich. In the summer of 1969, he undertook a second heart transplantation. Although the surgical procedure went well technically, both patients died within weeks to months after transplantation. Causes of death were infection in the first and rejection in the second patient. Senning’s colleagues around the world had similar experiences. Survival after heart transplantation was unacceptably low. The heart transplant community recognised the lack of knowledge about immunological processes and appropriate immunosuppressive regimens as underlying reason for the early deaths. Most transplant centres decided to refrain from heart transplantation until sufficient immunological insight became available. After the introduction of the new immunosuppressive drug ciclosporin into the clinic and the availability of tools to monitor rejection in the early 1980s, heart transplant programmes were restarted all over the world. The legal recognition of brain death allowed procurement of donor hearts without exposure to warm ischaemia, and the principle of cold storage enabled prolongation of ischaemia time and acceptance of donors in distant hospitals, resulting in enlargement of the donor pool. In Switzerland, Marko Turina resumed heart transplantation in 1985 at Senning’s former workplace in Zurich. The number of heart transplants in Switzerland and in the world grew rapidly because the outcome markedly improved. Particularly over the long-term, survival in Zurich surpassed the outcome worldwide. Zurich created internationally recognised milestones such as transplantation of patients with grown-up congenital heart disease, the implementation of the bicaval instead of the right atrial anastomosis during the transplant procedure and the dual transplantation of one heart. Since the middle of the 1990s, however, the number of heart transplants has plateaued, mainly because of donor shortage. The current era is characterised by efforts to increase the number of donors. The utilisation of marginal donors, the change from informed to presumed consent for organ donation and donation after cardiocirculatory-determined death have been proposed to augment the donor pool.

Incidence and pathophysiology of atrioventricular block following mitral valve replacement and ring annuloplasty.

BACKGROUND: In this retrospective study we evaluate the causative mechanisms underlying postoperative atrioventricular block (AVB) following mitral valve replacement and mitral valve annuloplasty. METHODS: Between January 1990 and December 2003, 391 patients underwent mitral valve replacement or ring annuloplasty and quadrangular resection. Exclusion criteria were preoperative AV block, two or three valvular procedures, reoperations and procedures combined with coronary artery bypass grafting. The presence of the postoperative AVB was compared with preoperative and intraoperative variables. On 55 post-mortem specimens the relationship between the AV node, AV node artery and mitral valve annulus was investigated. RESULTS: The mean age was 59+/-14 years and 44% of patients were female. Postoperatively AVB occurred in 92 (23.5%) patients. AVB III was found in 17 (4%) patents, in whom a pacemaker was implanted within median interval of 4 days. Second degree AVB occurred and first degree AVB in five (1.3%) and in 70 (18%) patients respectively. In dry dissected human hearts in 23% of investigated cases the AV node artery was discovered to run close to the annulus of the mitral valve. CONCLUSIONS: Data collected in this study showed that, sotalol and amiodarone as well as a prolonged cross-clamp time may slightly influence the 23% incidence of postoperative AVB. The morphological investigation showed that the AV node artery runs in close proximity to the annulus in 23% of cases. We speculate that damage of the AV node artery may play a role in development of AVB.

Annulus fibrosus of the mitral valve: reality or myth.

INTRODUCTION: Surgical repair of the mitral valve is in most cases limited to the posterior leaflet of the mitral valve and to the annulus fibrosus. The term annulus fibrosus is still used in anatomical and clinical terminology and is described as a cord like structure providing the attachment of the mitral vale. However, to date no evidence exists of a ring-or cord-like structure at this area. Herein, we describe the attachment of the mitral valve by using the macroscopical and microscopical techniques. MATERIAL AND METHODS: The ventricular attachment of the posterior mitral valve leaflet was investigated in 10 human hearts. In dry dissected specimens, the intraventricular illumination was used to identify the attachment of the mitral valve to the left ventricular muscle. Using the histological techniques, we verified the position of the annulus fibrosus. RESULTS: The attachment of the posterior mitral valve leaflet is a band-like structure positioned between the left ventricular muscle and the left atrium. This fibrous band illustrates the morphological attachment of the mitral valve and, as thus, was interpreted as the annulus fibrosus of the mitral valve. CONCLUSION: Based on our data, no ring-like structure was found corresponding to the anatomical description of the annulus fibrosus, instead the band-like fibrous tissue was identified positioned between the mitral valve and the left ventricle. Histologicaly, we detected that this structure is part of the greater structural system that is directly connected to the membranous septum, to the left and right fibrous trigone and the attachment aortic root to the left ventricular muscle.

Geometric models of the aortic and pulmonary roots: suggestions for the Ross procedure.

OBJECTIVE: To discuss geometric factors, which may influence long-term results relating to homograft competence following the Ross procedure, we describe the 3D morphology of the pulmonary and aortic roots. MATERIALS: Measurements were made on 25 human aortic and pulmonary roots. Inter-commissural distances and the heights of the sinuses were measured. For geometrical reconstruction the three commissures and their vertical projections at the root base were used as reference points. RESULTS: In the pulmonary root, the three inter-commissural distances were of similar dimensions (17.9+/-1.6mm, 17.5+/-1.4mm and 18.6+/-1.5mm). In the aortic root, the right inter-commissural distance was greatest (18.8+/-1.9mm), followed by the non-coronary (17.4+/-2.0mm) and left coronary sinus commissures (15.2+/-1.9mm). The mean height of the left pulmonary sinus was greatest (20+/-1.7mm) followed by the anterior (17.5+/-1.4mm) and right pulmonary sinus (18+/-1.66mm). In the aortic root, the height of the right coronary sinus was the greatest (19.4+/-1.9mm) followed by the heights of the non-coronary (17.7+/-1.8mm) and left coronary sinus (17.4+/-1.4mm). Measured differences between parameters determine the tilt angle and direction of the root vector. The tilt angle in the pulmonary root averaged 16.26 degrees , respectively; for the aortic roots, it was 5.47 degrees . CONCLUSIONS: Herein we suggest that the left pulmonary sinus is best implanted in the position of the right coronary sinus, the anterior pulmonary in the position of the non-coronary sinus and the right pulmonary sinus in the position of the left coronary sinus. In this way, the direction of the pulmonary root vector will be parallel to that of the aortic root vector.

Blood supply of the sternum and its importance in internal thoracic artery harvesting.

BACKGROUND: The internal thoracic artery (ITA) is the conduit of choice in coronary bypass grafting, due to the excellent long-term results achieved using it. However, increased incidence of sternal infections after pedicled ITA harvesting has revived interest in the morphology of sternal blood supply. Our aim was to discuss the topography of the sternal branches with emphasis on internal thoracic artery harvesting. METHODS: This study was conducted on 50 fresh specimens of the anterior thorax wall. Radio-opaque material was injected and angiograms of the ITA were performed. Subsequently, the specimens were preserved and a dry dissection of each ITA and its branches was carried out. RESULTS: In dry dissected specimens, four types of vessels were identified that have the potential to carry blood to the sternum after harvesting the ITA. In the first group, the artery to the sternum also supplies the intercostal space. In the second morphologic variant, the sternal branch gives off the perforating and anterior intercostal arteries. In the third group, we classified the common branch of the sternal and perforating arteries. In the fourth group, the sternal artery originated from the ITA as an independent branch. CONCLUSIONS: For sternal-intercostal, perforating-intercostal, and sternal-perforating branches to function as collaterals after ITA harvesting, the common trunk of origin must remain intact. Based on morphologic data, we recommend ligating the common trunk as close as possible to the ITA; in this way, collateral blood flow to the sternum remains intact.

Clinical anatomy of the atrioventricular node artery.

BACKGROUND AND AIM OF THE STUDY: The study aim was to describe the topographical relationship of the atrioventricular (AV) node artery and mitral valve annulus fibrosus with regard to AV node dysfunction following mitral valve replacement or ring annuloplasty. METHODS: The anatomy of the AV node artery was analyzed in 55 human hearts without previous pathological alterations. Selective coronary angiograms were performed to identify the AV node origin. Run-off of the AV node artery and its topographical relationship to the mitral valve attachment was analyzed in dry-dissected hearts. The position of the AV node was verified by histological sectioning. RESULTS: The AV node artery originated from the right coronary artery in 73% of examined cases, and from the left coronary artery in 27% of cases. The left AV node artery was closely related to the mitral valve attachment, especially at the area of the left proximal part of the posterior leaflet. CONCLUSION: These morphological data were compared to clinical reports emphasizing the postoperative incidence of AV block after mitral valve implantation and ring annuloplasty. The occurrence of early postoperative AV node block ranged from 20% to 37%. By comparing the present data with available literature, it can be stated that there is a high risk of intraoperative damage to the left AV node artery during manipulation of the mitral valve annulus fibrosus.

Respiratory dependent compression of a venous bypass: therapy by stenting.

Although coronary artery bypass surgery has provided major advances in the treatment of coronary artery disease, narrowing of bypass vessels still constitutes a drawback of this therapy. Although this event is most frequently caused by intraluminal processes, obstruction from external structures is extremely rare. We report such a case in which external bypass compression was provoked by deep inspiration causing typical anginal symptoms. Percutaneous coronary intervention including stent placement provided bypass patency independent from the patient's respiratory phase. Disappearance of symptoms and absence of myocardial ischemia in perfusion scans confirmed successful treatment.

Aortic dissection with potential origin from a mechanical bypass anastomosis.

Ascending aortic dissection is a known complication of cardiac surgery. Off-pump coronary artery bypass surgery seems to be associated with a higher risk for this event as compared with on-pump bypass surgery. This increased risk may result from aortic side-clamping under pulsatile flow as opposed to continuous flow in conventional bypass surgery. Mechanical devices allowing performance of proximal bypass anastomoses without aortic side-clamping are supposed to reduce the risk for aortic dissection. We report a case in which ascending aortic dissection occurred 8 days after off-pump bypass surgery, most likely arising from a mechanically performed proximal bypass anastomosis.

In the footsteps of senning: lessons learned from atrial repair of transposition of the great arteries.

The Senning operation has evolved from being the initial surgical correction that allowed survival in complete transposition of the great arteries to an integral part of the anatomic repair of congenitally corrected transposition. In patients with complete transposition, the Senning operation has given satisfactory initial and long-term surgical results, but the potential for right ventricular failure and atrial arrhythmias have drastically reduced its indications in the current era. The long-term follow-up and pertinent postoperative issues of the Senning operation will be reviewed, along with its newfound role in the anatomic repair of congenitally corrected transposition.

Normalization of high pulmonary vascular resistance with LVAD support in heart transplantation candidates.

OBJECTIVE: Pulmonary hypertension (PH) and elevated pulmonary vascular resistance (PVR) lead to poor outcome after heart transplantation due to postoperative failure of the non-conditioned right ventricle. The role of continuous flow left ventricular assist device (LVAD) support in the reduction of elevated PVR was evaluated in a series of clinical implants. METHODS: Among 17 patients with terminal heart failure receiving a MicroMed DeBakey LVAD as bridge to transplant, there were six patients with pulmonary hypertension (mean systolic PAP 47 mmHg) and high PVR (398 dynes/cm5), previously not considered suitable for heart transplantation, who underwent serial right heart catheters during their LVAD support period. RESULTS: In these patients mean systolic pulmonary pressure dropped to 29 mmHg and PVR decreased to a mean 167 dynes/cm5 under LVAD support. Clinical improvement was significant in all patients. Four patients were successfully transplanted without major postoperative difficulties (mean duration 130 days support) and all are doing well to date. Post-transplant-PVR remained in the normal range in all transplanted patients. CONCLUSIONS: Elevated PVR and severe PH were both previously considered as contraindication for heart transplantation. A period of LVAD pumping leads to a progressive decrease of PVR and normalization of pulmonary pressures, making these patients amenable for heart transplantation. LVAD as bridge to heart transplantation is safe and highly beneficial for terminal heart failure patients with severe PH.

A new classification of the mitral papillary muscle.

BACKGROUND: Mitral valve homograft implantation and reconstruction of the left ventricular subvalvular apparatus requires a good knowledge of the morphology of the left papillary muscles. A comprehensive description of the left ventricular subvalvular apparatus is presented to aid in this procedure and to support conventional and endoscope-assisted reconstruction of the chordae tendineae. MATERIAL/METHODS: The subvalvular apparatuses of 100 unfixed human hearts were investigated. Papillary muscles were endoscopically examined on the hearts in situ, then the hearts were explanted and the subvalvular apparatus was macroscopically inspected. The geometrical arrangement of the chordae tendineae was determined. RESULTS: We defined three groups of the left ventricular papillary muscle. In group I the basal part and the apex of the muscle were undivided. In group II there were two heads; in subgroup II/A the base of the papillary muscle was undivided and in II/B it was divided into two separate parts. In group III the papillary muscle had three heads. In subgroup III/A the base was undivided, while in III/B it was made up of two and in III/C three separate parts. CONCLUSIONS: We propose a classification of the left ventricular subvalvular apparatus based on the macroscopic and endoscopic investigations. It emphasizes the morphology of the apical and basal parts of papillary muscles and includes the geometrical arrangement of the chordae tendineae. Thus it may be of a great value in endoscopic and conventional mitral valve replacement or reconstruction of the chordae tendineae and in mitral valve homograft implantation.