Catastrophic hemorrhage on sternal reentry: still a dreaded complication?

Application of Biosheets as Right Ventricular Outflow Tract Repair Materials in a Rat Model

Purposes

We report the experimental use of completely autologous biomaterials (Biosheets) made by “in-body tissue architecture” that could resolve problems in artificial materials and autologous pericardium. Here, Biosheets were implanted into full-thickness right ventricular outflow tract defects in a rat model. Their feasibility as a reparative material for cardiac defects was evaluated.

Methods

As the evaluation of mechanical properties of the biosheets, the elastic moduli of the biosheets and RVOT-free walls of rats were examined using a tensile tester. Biosheets and expanded polytetrafluoroethylene sheet were used to repair transmural defects surgically created in the right ventricular outflow tracts of adult rat hearts (n = 9, each patch group). At 4 and 12 weeks after the operation, the hearts were resected and histologically examined.

Results

The strength and elastic moduli of the biosheets were 421.3 ± 140.7 g and 2919 ± 728.9 kPa, respectively, which were significantly higher than those of the native RVOT-free walls (93.5 ± 26.2 g and 778.6 ± 137.7 kPa, respectively; P < 0.005 and P < 0.001, respectively). All patches were successfully implanted into the right ventricular outflow tract-free wall of rats. Dense fibrous adhesions to the sternum on the epicardial surface were also observed in 7 of 9 rats with ePTFE grafts, whereas 2 of 9 rats with biosheets. Histologically, the vascular-constructing cells were infiltrated into Biosheets. The luminal surfaces were completely endothelialized in all groups at each time point. There was also no accumulation of inflammatory cells.

Conclusions

Biosheets can be formed easily and have sufficient strength and good biocompatibility as a patch for right ventricular outflow tract repair in rats. Therefore, Biosheet may be a suitable material for reconstructive surgery of the right ventricular outflow tract.

Adhesion barriers in cardiac surgery: A systematic review of efficacy

BACKGROUND

Postoperative pericardial adhesions have been associated with increased morbidity, mortality, and surgical difficulty. Barriers exist to limit adhesion formation, yet little is known about their use in cardiac surgery. The study presented here provides the first major systematic review of adhesion barriers in cardiac surgery.

METHODS

Scopus and PubMed were assessed on November 20, 2020. Inclusion criteria were clinical studies on human subjects, and exclusion criteria were studies not published in English and case reports. Risk of bias was evaluated with the Cochrane Risk of Bias Tool. Barrier efficacy data was assessed with Excel and GraphPad Prism 5.

RESULTS

Twenty-five studies were identified with a total of 13 barriers and 2928 patients. Polytetrafluoroethylene (PTFE) was the most frequently evaluated barrier (13 studies, 67% of patients) with adhesion formation rate of 37.31% and standardized tenacity score of 26.50. Several barriers had improved efficacy. In particular, Cova CARD had a standardized tenacity score of 15.00.

CONCLUSIONS

Overall, the data varied considerably in terms of study design and reporting bias. The amount of data was also limited for the non-PTFE studies. PTFE has historically been effective in preventing adhesions. More recent barriers may be superior, yet the current data is nonconfirmatory. No ideal adhesion barrier currently exists, and future barriers must focus on the requirements unique to operating in and around the heart.

Early cardiac contractility outcome of reoperative coronary artery bypass grafting using right gastroepiploic artery

BACKGROUND AND AIM OF THE STUDY

Reoperative coronary artery bypass grafting (redo CABG) still carries higher mortality and increased morbidity compared with primary CABG. In this study, we retrospectively reviewed our operative outcome of redo CABG to evaluate the impact of the left anterolateral thoracotomy approach using the right gastroepiploic artery (RGEA).

METHODS

Between 1994 and 2020, 11 patients (mean age 60.3 ± 13.1 years; nine men, two women) underwent isolated redo CABG using the RGEA via the left anterolateral thoracotomy.

RESULTS

The mean duration from the initial CABG was 128.3 ± 88.4 months. Redo CABG was performed because of graft occlusion in six patients (54.5%), graft stenosis in one patient (9.1%), and progressive disease of previously ungrafted vessels in four patients (36.4%). The total number of bypasses using RGEA (including Y-composite vein grafts) was 16 (four left anterior descending branches, two diagonal branches, five circumflex branches, five right coronary arteries). No residual graft injury, major comorbidity, or in-hospital death was observed. Changes in echocardiographic values before and after redo CABG were 210.9 ± 48.2 ml and 175.0 ± 41.4 ml in left ventricular end-diastolic volume, 130.2 ± 49.2 ml and 94.4 ± 33.0 ml in left ventricular end-systolic volume, and 45.6 ± 11.0% and 52.2 ± 10.7% in left ventricular ejection fraction, respectively. These parameters significantly improved after redo CABG.

CONCLUSIONS

Redo CABG with RGEA grafting via the left anterolateral thoracotomy approach is a safe and effective surgical procedure especially in improving cardiac contractility in patients who required revascularization.

Video-assisted thoracoscopic sternal adhesiolysis before resternotomy reduces morbidity and improves patient care

BACKGROUND

Resternotomy still carries an important risk for an already high-risk population. Re-entry injuries may lead to massive bleeding, which can be difficult to control due to poor accessibility. The aim of the study was to assess early outcomes of video-assisted thoracoscopic adhesiolysis, as well as safety and feasibility.

METHODS

Forty-five patients received a video-assisted thoracoscopic adhesiolysis before resternotomy between April 1, 2016 and January 1, 2019. Records were reviewed for demographics, perioperative and early postoperative (Postop) outcomes.

RESULTS

The median age of the population was 73 years with a EUROSCORE II of 8.322. Only 1 (2.22%) patient experienced a major and 2 (4.44%) a minor re-entry injury. This resulted in a mean peroperative and 24-hour Postop blood loss of, respectively, 675.72 (range: 5-2862) and 444.71 mL (range: 0-2100). There was no significant difference between the use of minimally invasive and classic extracorporeal circulation (P = .276 and P = .81, respectively). Twenty-nine patients (64%) were not in need of red blood cell transfusion. A survival rate of 93.33% could be achieved. No deaths (n = 3) were related to the video-assisted thoracoscopic adhesiolysis or re-entry injuries. Kidney function remained stale postoperatively with creatinine preoperative and Postop levels of 1.56 (95%confidence interval: 1.07-2.05) and 1.43 (95%CI, 1.05-1.81) mg/dL (P = .264). Despite high-risk surgery, the median length of stay was 8 days.

CONCLUSION

A video-assisted thoracoscopic approach allows for a safe and effective adhesiolysis, due to increased visibility and accuracy. This approach may prevent major and minor re-entry injuries and consequently reduce perioperative morbidity and mortality of high-risk surgery.

MDCT prior to median re-sternotomy in cardiovascular surgery: our experiences, infrequent findings and the crucial role of radiological report

Resternotomy (RS) is a common occurrence in cardiac surgical practice. It is associated with an increased risk of injury to old conduits, cardiac structures, catastrophic hemorrhage and subsequent high morbidity and mortality rate in the operating room or during the recovery period. To mitigate this risk, we evaluated the role of multidetector CT (MDCT) in planning repeat cardiac surgery. We evaluated sternal compartment abnormalities, sternal/ascending aorta distance, pre-reoperative assessment of the aorta (wall, diameters, lumen, valve), sternal/right ventricle distance, diaphragm insertion, pericardium and cardiac chambers, sternal/innominate vein distance, connection of the grafts to the predicted median sternotomy cut, graft patency and anatomic course, possible aortic cannulation and cross-clamping sites and additional non-cardiovascular significant findings. Based on the MDCT findings, surgeons employed tailored operative strategies, including no-touch technique, clamping strategy and cardiopulmonary bypass (CPB) via peripheral cannulation assisted resternotomy. Our experience suggests that MDCT provides information which contributes to the safety of re-operative heart surgery reducing operative mortality and adverse outcomes. The radiologist must be aware of potential surgical options, including in the report any findings relevant to possible resternotomy complications.

Percutaneous coronary intervention followed by minimally invasive valve surgery compared with median sternotomy coronary artery bypass graft and valve surgery in patients with prior cardiac surgery

BACKGROUND

In patients with prior cardiac surgery requiring re-operative coronary and valve surgery, a hybrid approach of percutaneous coronary intervention followed by minimally invasive valve surgery (PCI + MIVS) may be an alternative to the standard median sternotomy coronary artery bypass and valve surgery (CABG + valve).

METHODS

The outcomes of patients with prior cardiac surgery, presenting with coronary artery and valvular disease, who underwent PCI + MIVS (N=39) were retrospectively compared with those who underwent CABG + valve (N=28) via a repeat median sternotomy, between February 2009 and April 2014.

RESULTS

The mean age for the PCI + MIVS versus CABG + valve group was 75±9 and 72±11 years (P=0.54), respectively. The baseline characteristics were similar between groups, with the exception of a greater prevalence of 1-vessel coronary artery disease and clopidogrel or dual antiplatelet therapy at the time of surgery in the PCI + MIVS group, and more 3-vessel coronary artery disease in those undergoing CABG + valve surgery. The PCI + MIVS approach was associated with a decreased aortic cross-clamp (94 vs. 131 minutes, P=0.001) and cardiopulmonary bypass (128 vs. 190 minutes, P<0.001) times, fewer intraoperative packed red blood transfusions (1.3 vs. 3.8 units, P=0.001), shorter intensive care unit length of stay (41 vs. 71 hours, P<0.001), and decreased incidence of prolonged mechanical ventilation (12.8% vs. 35.7%, P=0.03), re-intubation (2.6% vs. 17.9%, P=0.04), when compared with CABG + valve. The thirty-day and two-year mortality were similar, being 7.7% vs. 7.1% (P=0.66), and 12.8% vs. 10.7% (P=0.55), in the PCI + MIVS vs. CABG + valve group, respectively.

CONCLUSIONS

Hybrid PCI + MIVS in patients with prior cardiac surgery is associated with shorter operative times and intensive care unit length of stay, less need for intraoperative blood cell transfusions, decreased use of mechanical ventilation, and similar short-term and follow-up survival, when compared with CABG + valve surgery via median sternotomy. Randomized trials and multicenter registries are needed to further evaluate this approach.

Hybrid Repair of Ruptured Arch Aneurysm Without Sternotomy Through an Unusual Extraanatomic Bypass

A 42-year-old man experienced a complex aortic arch aneurysm rupture. He had previously undergone an operation for type A dissection and had extremely poor cardiac performance as well as deep sternal infection after the first procedure. The conventional open repair was considered to be a high risk for this patient. We therefore performed an alternative hybrid aortic procedure. The supraarch vessels were perfused through an extraanatomic bypass from an unusual and remote route, namely, the abdominal aorta. Then, stent grafts were implanted in the previously replaced aortic prostheses to exclude the aortic aneurysm. The patient recovered uneventfully with no neurologic adverse events.

Combined Mitral and Tricuspid Valve Surgery Performed via a Right Minithoracotomy Approach

OBJECTIVE

Combined mitral and tricuspid valve surgery is associated with an increased perioperative morbidity and mortality. We evaluated the outcomes of a less invasive right minithoracotomy approach in patients undergoing primary or reoperative double-valve surgery.

METHODS

We retrospectively evaluated 132 consecutive patients with mitral and tricuspid valve disease who underwent double-valve surgery via a right minithoracotomy at our institution between January 2009 and April 2014.

RESULTS

The cohort included 81 female (61%) and 51 male (39%) patients, with a mean ± SD age of 67 ± 13 years. The mean ± SD preoperative left ventricular ejection fraction, mitral regurgitation grade, and creatinine were 53% ± 12%, 3.8 ± 0.6, and 1.26 ± 1.17, respectively. The patients underwent primary (88%) or reoperative (12%) mitral and tricuspid valve surgery, which consisted of 88 mitral repairs (67%), 44 mitral replacements (33%), 131 tricuspid repairs (99%), and 1 tricuspid replacement (1%). Postoperatively, there were 6 cases of acute kidney injury (5%), 6 reoperations for bleeding (5%), 4 cerebrovascular accidents (3%), and 12 cases of atrial fibrillation (9%). The median intensive care unit length of stay and total hospital lengths of stay were 61 hours (interquartile range, 43-112 hours) and 8 days (interquartile range, 6-13 days), respectively. The in-hospital mortality was 4%. Actuarial survival at 1 and 5 years was 93% and 88%, respectively.

CONCLUSIONS

In patients undergoing primary or reoperative mitral and tricuspid valve surgery, a right minithoracotomy approach is associated with a low perioperative morbidity and good midterm survival.

A Simplified Arch Debranching Technique for Hybrid Repair of Complicated Type B Aortic Dissection

Convenient procedures and fewer postoperative adverse events of an arch debranching technique are important factors that need to be considered for assured outcomes of hybrid repair. In this report we describe our hybrid repair with a simplified arch debranching technique. It was used for patients with complicated type B aortic dissection who had undergone previous operations for type A aortic dissection. With this technique, the treatment for complicated type B aortic dissection becomes easier and less invasive, which is especially advantageous for patients with high surgical risk for conventional open repair.

Is Seprafilm valuable in infant cardiac redo procedures?

BACKGROUND

Morbidity and mortality are higher for cardiac reoperations than first operation due to the presence of post-operative adhesions. We retrospectively evaluated the efficacy of the bioresorbable membrane Seprafilm to prevent pericardial adhesions after cardiac surgery in a paediatric congenital heart disease population.

METHODS

Seventy-one children undergoing reoperations with sternotomy redo and cardiopulmonary bypass for congenital malformations were included. Twenty-nine of these patients were reoperated after previous application of Seprafilm (treatment group). The duration of dissection, aortic cross clamping and total surgery were recorded. A tenacity score was established for each intervention from the surgeon's description in the operating report.

RESULTS

In multivariate analysis, the duration of dissection and the tenacity score were lower in the treatment than control group (p < 0.01), independent of age and interval since preceding surgery.

CONCLUSION

Our results suggest that Seprafilm is effective in reducing the post-operative adhesions associated with infant cardiac surgery. We recommend the use of Seprafilm in paediatric cardiac surgery when staged surgical interventions are necessary.

Redo off-pump coronary artery bypass grafting via a left thoracotomy

BACKGROUND

In this study, we retrospectively reviewed our experience in a meticulously selected group of patients undergoing redo off-pump coronary artery bypass graft (CABG) surgery from the descending aorta to the circumflex artery (Cx) and its branches.

METHODS

Between January 2001 and October 2013, 32 patients at our hospital underwent redo off-pump CABG from the descending aorta to the Cx and its branches via a left posterolateral thoracotomy. Of these patients, 27 were male (84.3%) and five were female (15.7%), with a mean age of 61.66 ± 8.63 years. All patients had a patent left internal thoracic artery-to-left anterior descending coronary artery (LITA-LAD) anastomosis. Thoracotomy was performed through the fifth intercostal space. The saphenous vein or radial artery was prepared as a graft at the same time as the left posterolateral thoracotomy from the contralateral extremity, without any positional problem.

RESULTS

The main reasons for surgery in this group of patients were new lesion formation in 19, graft occlusion in six, and both in seven patients. The average operating time was 143.90 ± 36.93 minutes, respiratory assist time was 5.08 ± 1.88 hours, intensive care unit (ICU) stay was 21.3 ± 4.41 hours and hospital stay was 5.06 ± 2.74 days. Thirty-eight bypasses were performed. The follow-up period was 56.17 ± 39.2 months. Six patients were lost in the follow-up period and four patients died. Twenty-two were alive and free of cardiac problems.

CONCLUSION

Redo off-pump CABG via a left posterolateral thoracotomy provided a safe and effective surgical approach with lower rates of postoperative morbidity and mortality in patients who required revascularisation of the Cx and its branches.

Two-vessel off-pump coronary artery bypass grafting by left thoracotomy in a complex reoperative case

An 83-year-old male with a history of three prior sternotomies, including coronary artery bypass surgery (CABG), presented with unstable angina. Cardiac catheterization showed left main and triple-vessel disease. The saphenous vein graft (SVG) to the right coronary artery was diseased but patent, and the SVG to the left anterior descending artery (LAD) was occluded. Preoperative evaluation showed a heavily calcified ascending aorta and minimum disease on the descending aorta. He successfully underwent a left thoracotomy 2-vessel off-pump CABG using the descending aorta for the proximal anastomosis. The left thoracotomy approach is a useful alternative to avoid complications associated with resternotomy, especially in patients with a hostile chest, although visualization of the target vessels may be limited.

Mitral valve reoperation under ventricular fibrillation through right mini-thoracotomy using three-dimensional videoscope

BACKGROUND

Conventional reoperative mitral valve surgery by median sternotomy has several difficulties. We performed mitral valve replacement (MVR) under ventricular fibrillation (VF) through right mini-thoracotomy with three-dimensional videoscope for avoiding the problems.

METHODS

Between 2006 and 2011, we performed 257 cases of MVR, in which 125 cases underwent isolated MVR. Ten cases of patients underwent reoperative MVR under VF through thoracotomy with three-dimensional videoscope (Group I), and 27 cases of patients underwent reoperative conventional MVR through median sternotomy (Group II). We retrospectively reviewed the outcomes and compared Group I with Group II. Preoperative left ventricular ejection fraction (LVEF) was significantly lower (50.5 ± 19.8% vs 64.4 ± 12.0%; p = 0.046), and significantly higher Euro SCORE was found in Group I (4.8 ± 2.0 vs 3.8 ± 2.4; p = 0.037).

RESULTS

Although Group I required cooling and rewarming time, average operative times was significantly shorter in Group I (262 ± 46 min vs 300 ± 57 min; p = 0.044), and cardiopulmonary bypass times and average VF times in Group I and aortic cross-clamp times in Group II were equivalent. There was no significant difference in the average of postoperative maximum creatine kinase (CK)-MB. In-hospital mortality was 0/10 (0%) and 1/27 (3.7%), and postoperative paravalvular leakage occurred in 0/10 (0%) and 1/27 (3.7%), and stroke occurred in 1/10 (10%) and 1/27 (3.7%) for Groups I and II. Two patients underwent reoperation for bleeding in Group II. Intensive care unit stay in Group I was significantly shorter than in Group II (1.8 ± 0.6 days vs 3.0 ± 1.7 days; p = 0.025).

CONCLUSIONS

The higher risk of preoperative background in Group I had no effect on the operation. Mitral valve surgery under VF through right mini-thoracotomy can be an alternative procedure for reoperation after conventional various cardiothoracic surgeries.

A review of the current status of pericardial closure following cardiac surgery

Some cardiac surgeons prefer to close the pericardium whenever possible following surgery, others specifically avoid this practice, and still others believe that neither alternative has any meaningful influence on clinical outcomes. Unfortunately, scientific evidence supporting either approach is scarce, making a consensus regarding best practice impossible. In this article, the known functions of the native intact pericardium are summarized, and the arguments for and against pericardial closure after surgery are examined. In addition, the techniques and materials that have been utilized for pericardial closure previously, as well as those that are currently being developed, are assessed.

Is resternotomy a risk for continuous-flow left ventricular assist device outcomes?

BACKGROUND

The number of patients undergoing resternotomy continues to rise. Although catastrophic hemorrhage remains a dreaded complication, most published data suggest that sternal reentrance is safe, with negligible postoperative morbidity and mortality. A significant proportion of left ventricular assist device (LVAD) implantations are reoperative cardiac procedures. The aim of our study was to compare outcomes between first time sternotomy and resternotomy patients receiving continuous-flow LVADs, as a bridge to transplantation or destination therapy.

METHODS AND MATERIALS

From March 2006 through February 2012, 100 patients underwent implantation of a HeartMate II or HeartWare LVAD at our institution. Patients were stratified into two groups, primary sternotomy and resternotomy. Variables were compared using two-sided t-tests, chi-square tests, Cox proportional hazards models, and log-rank tests to determine whether there was a difference between the two groups and if resternotomy was a significant independent predictor of outcome.

RESULTS

We identified 29 patients (29%) who had resternotomy and 71 patients (71%) who had first time sternotomy. The resternotomy group was significantly older (56 years vs. 51 years, p = 0.05), was more likely to have ischemic cardiomyopathy (ICM) (69% vs. 30%, p < 0.001), chronic obstructive pulmonary disease (COPD) (31% vs. 14%, p = 0.05) and had longer cardiopulmonary bypass times (135 min vs. 100 min, p = 0.011). Survival rates at 30 days (93.1% vs. 95.8%, p = 0.564), 180 days (82.8% vs. 93%, p = 0.131), and 360 days (82.8% vs. 88.7%, p = 0.398) were similar for the resternotomy and primary sternotomy groups, respectively. Postoperative complications were also comparable, except for re-exploration for bleeding which was higher for the resternotomy group (17.2% vs. 4.2%, p = 0.029), although blood transfusion requirements were not significantly different (1.4 units vs. 1.2 units, p = 0.815). Left and right heart catheterization measurements and echocardiographic (ECHO) findings after 1 and 6 months of LVAD therapy were similar between the two groups.

CONCLUSIONS

Survival at 30, 180, and 360 days after LVAD implantation is similar between the resternotomy and primary sternotomy group. No major differences in complications or hemodynamic measurements were observed. Although a limited observational study, our findings agree with previously published resternotomy outcomes.

Two approaches for repeat cardiac surgery

BACKGROUND

With recent advances in post-operative care and surgical methods, the number of cardiovascular re-operations is increasing. We analyzed our institutional experience to evaluate the safety and efficacy of the approach methods for cardiac re-operations.

METHODS

Between September 2007 and December 2010, we performed 208 cardiac re-operations, defined as surgery which was not performed within a month from the previous operation or during the same hospitalization for the same disease and reviewed retrospectively. According to the surgical approach, we divided patients into two groups: median sternotomy group (S-group, n = 146), and thoracotomy group (T-group, n = 62).

RESULTS

There were no differences in sex or mean interval from the first surgery to re-operation between the two groups. Mean cardiopulmonary bypass, adhesion dissection time, bleeding control time, and operation time were significantly shorter in the T-group. The need for transfusion (p = 0.001) during adhesion dissection and the chest tube drainage (p < 0.001) were significantly lower in the T-group. There were 10 operative deaths in the S-group (6.8%) and 5 in the T-group (8.1%) (p = 0.757). Pneumonia was the most common cause of death in both groups. Post-operative bleeding did not result in death and there were no cases of wound infection in the T-group.

CONCLUSIONS

Two approaches for repeated cardiac surgery were safe and effective in terms of mortality, wound infection, bleeding, operation time, adhesion dissecting time, and bleeding control time. We were able to obtain a good visual field and perform safe surgery by applying the thoracotomy method in selective patients for cardiovascular re-operation.

Sternotomy following minimally invasive thoracoscopic procedures: a word of caution

An increasing number of patients with previous minimally invasive thoracic procedures for anterior mediastinal tumors are now requiring cardiac surgery. This paper highlights the potential damage that can occur when standard sternal splitting techniques are used in these patients.

Hybrid arch repair including supra-aortic debranching on the descending aorta

A 49-year-old patient with an anastomotic pseudoaneurysm in the aortic arch was considered at high risk for conventional surgery through a median sternotomy because he had previously undergone several operations to treat aortic dissection and had a deep sternal infection after one procedure. Therefore, a hybrid repair was performed. Stent grafts were placed bridging two previously implanted aortic prostheses, which were in the ascending aorta and descending aorta, respectively. The supra-arch vessels were perfused by means of an extra-anatomic bypass from the descending aorta. The aneurysm was completely excluded from the blood flow, and the patient had no serious complications.

Reoperative coronary artery bypass grafting via left thoracotomy and hypothermic fibrillation

Left posterolateral thoracotomy approach for reoperative coronary artery bypass grafting (CABG) is a useful alternative to median sternotomy. We describe use of a left posterolateral thoracotomy and hypothermic fibrillation for reoperative CABG in a patient with patent bilateral internal thoracic artery grafts.

Successful Implantation of a Left Ventricular Assist Device After Treatment With the Paracor HeartNet

The Paracor HeartNet, a ventricular constraint device for the treatment of heart failure (HF), is implanted through a left lateral thoracotomy. It envelopes the heart like a mesh "bag." This method of application raises the question of whether adhesions with the pericardium allow the safe implantation of a left ventricular assist device (LVAD) if HF worsens. A male patient who had undergone implantation of the Paracor HeartNet 42 months earlier presented with advanced HF for cardiac transplantation. The patient's condition deteriorated, and because no suitable organ for transplantation was available, implantation of an LVAD became necessary. Surgery was performed via a median sternotomy without complications. No severe adhesions were found. This is the first report on "how to do" LVAD implantation after Paracor HeartNet implantation with images and information about cutting the constraint. Because the Paracor HeartNet is "wrapped" around the heart, concerns persist that severe adhesions with the pericardium might occur. In this case, LVAD implantation after therapy with the Paracor HeartNet was without complications, and the expected massive adhesions were absent.

Evaluation of a synergistic handheld instrument for resternotomy controlled by an integrated optical sensor

Re-Sternotomy is an important part of many interventions in cardiac or thoracic surgery. It is performed close to critical structures such as the ascending aorta or the heart with an inherent high risk of serious damage. In this paper, a system for improving the safety of this surgical procedure is presented. A soft tissue preserving saw is combined with automatic depth regulation. The depth is controlled on the basis of the optical characteristics (visible light) of the tissue aligned to the saw blade, which is analyzed using a color sensor. Detection of the blades' position in the bone during the cutting process is possible through the integration of an optical fiber into the tip of the saw blade. The automatic depth control is realized using a hysteresis controller running on a real time system. To show the feasibility of this approach, the sensor technology was integrated into a prototypal sternal saw and evaluated on artificial bone. As part of the experiments the influence of water for cooling and dust particles from the process on the systems control stability were analyzed. The system performed stable and accurate. Future research will focus on the control algorithm and cadaver trials.

Prevention of postoperative pericardial adhesions in children with hypoplastic left heart syndrome

Reoperations for congenital cardiac defects are associated with an increased surgical risk due to adhesions. We compared the capability of a polytetrafluoroethylene (PTFE) membrane, synthetic polyethyleneglycol hydrogel (PEG), and a combination of them to prevent postoperative pericardial adhesions in patients with hypoplastic left heart syndrome (HLHS). Eighteen consecutive patients with HLHS were included. At the end of the Norwood I operation the cranial and the caudal half of the heart of each patient was randomized to receive a PTFE membrane, a synthetic PEG, a combination of them, or no treatment (control). Tenacity and density of adhesions, epicardial visibility, and adhesions between the heart and the sternum were analyzed semiquantitatively at a subsequent bidirectional Glenn operation. The PTFE membrane significantly decreased adhesion formation between the heart and the sternum (P<0.001). However, the PTFE membrane, with or without synthetic PEG, impaired epicardial visibility (P<0.05) when compared to synthetic PEG or controls. Synthetic PEG alone did not significantly reduce the formation of pericardial adhesions. Tenacity and density of adhesions were not affected by any of the treatment modalities. The PTFE membrane significantly decreases postoperative adhesions between the heart and the sternum, but impairs epicardial visibility. Synthetic PEG does not prevent formation of pericardial adhesions.

Is resternotomy in cardiac surgery still a problem?

Multiple factors contribute to the growing number of reoperations for congenital and acquired cardiovascular diseases in the United States. Although the hazards are well-recognized, the health economic burden of resternotomy (RS) remains unclear and may be difficult to quantify. Contrary to published studies citing low frequencies of catastrophic hemorrhage and mortality, survey responses from practicing surgeons disclose higher rates of complications. Safety strategies in cardiac reoperation have generally involved efforts to maximize visualization during dissection, specialized surgical maneuvers and instrumentation, customized methods for establishing extracorporeal circulation, and techniques to prevent or avoid retrosternal adhesions. Yet, the relative cost-effectiveness of these strategies is largely unexplored. With the ongoing constraints in healthcare budgets, differentiating the value of existing and future approaches in terms of relative clinical benefits, costs, and impact on resource utilization will become increasingly important. We reviewed the relevant published literature in order to survey the morbidity and resource utilization associated with RS in cardiac reoperation and to identify key issues relevant for future studies.

Retrospective review of reoperative pectus excavatum repairs

BACKGROUND/PURPOSE

Despite success of several techniques described for pectus excavatum repair, a minority of patients require multiple reoperations for recurrence or other complications. We aimed to review our experience in reoperative pectus excavatum repairs and to identify features correlating with need for additional reoperations.

METHODS

Charts were reviewed of all patients undergoing reoperative pectus excavatum repair for 3 years at a university-based children's hospital. Number and type of previous repairs, time between operations, lengths of stay, analgesia, and complications were recorded.

RESULTS

From February 2004 to December 2007, 170 pectus excavatum repairs were performed. Among these, 27 were reoperative. Overall, 18.2% of reoperative patients required subsequent additional reoperations. 21.1% of patients undergoing repeat open repairs and 33.3% of patients undergoing repeat minimally invasive repairs required further operative interventions. There was no need for additional repairs among patients who had open repairs after minimally invasive repairs, nor for any patients who had minimally invasive repairs after open repairs.

CONCLUSIONS

We conclude that patients with failed open repairs will have better success with minimally invasive reoperations, whereas patients with failed minimally invasive repairs will have better success with open reoperations. When faced with reoperative pectus excavatum, we recommend consideration of an alternative operative approach from the initial procedure.

Reoperation of the proximal aorta: impact of presternotomy extracorporeal circulation on clinical outcomes

PURPOSE

Adverse events can occur during a sternotomy for reoperation of the proximal aorta. Presternotomy extracorporeal circulation is often employed to avoid catastrophic events. The purpose of this study was to investigate the impact of presternotomy extracorporeal circulation on clinical outcomes of redo proximal aortic surgery.

METHODS

Between January 1990 and December 2005 a total of 21 aneurysms or dissections of the proximal aorta were repaired via a repeat sternotomy. Extracorporeal circulation was established before the sternotomy in 9 (49%) patients and after the sternotomy in 12 (51%) patients.

RESULTS

There were no statistically significant differences in the age, sex, emergency surgery, chronic obstructive pulmonary disease, and renal function between the groups. Femoral cannulation was used more often in the presternotomy extracorporeal circulation group (8/9, 89% vs. 1/12, 8.3%; P = 0.000). The difference in the pump time did not reach a statistically significant level. The 30-day and in-hospital mortality rates were 11% (1/9) and 11% (1/9) in the presternotomy extracorporeal circulation group and 0% (0/12) and 17% (2/12) in the poststernotomy extracorporeal circulation group. There were no statistically significant differences in stroke, respiratory failure, myocardial infarction, or renal failure. There was a trend toward a longer hospital stay in the presternotomy extracorporeal circulation group (85.8 vs. 48.1 days; P = 0.06).

CONCLUSION

Presternotomy extracorporeal circulation was not associated with any major adverse outcomes such as death, stroke, or renal failure.

Catastrophic hemorrhage due to aortic injury during resternotomy: what to do?

Aortic injury occurred during resternotomy in a 22-year-old woman who had undergone a Rastelli-type operation. Although extracorporeal circulation using the right femoral artery and vein was commenced immediately, hemostasis through the midline incision was impossible, and her circulation was hardly maintained. Thus, the parasternal approach was attempted, dividing the right first through fourth ribs and the head of the right clavicle. This approach enabled the assistant to give effective compression to the aortic injury site. Dissection of the adhesions around the ascending aorta was safely carried out, and the aortic laceration was closed without the help of circulatory arrest.

Repeat sternotomy in congenital heart surgery: no longer a risk factor

BACKGROUND

The risk of repeat sternotomy (RS) is often taken into account when making clinical management decisions. Current literature on RS suggests a risk of approximately 5% to 10% for major morbidity. We sought to establish the true risk of RS in a contemporary pediatric series.

METHODS

All RS between October 2002 and August 2006 were analyzed (602 RS in 558 patients). Median age was 3.6 years (range, 0.1 to 45.1); weight, 14.2 kg (2.0 to 112.2). Operations performed at RS were Glenn 22% (131), Fontan 21% (129), aortic valve repair/replacement 12% (72), right ventricle-pulmonary artery conduit 11% (67), Rastelli 7% (39), heart transplant 5% (31), and other 22% (133). Forty-seven percent of patients (280) had single-ventricle physiology. Incidence of second sternotomy was 67% (406), third 28% (166), fourth 4% (24), fifth 0.8% (5), and sixth 0.2% (1). A major injury upon RS was defined as one causing hemodynamic instability requiring vasopressor support or emergent transfusion; femoral cannulation or emergent cardiopulmonary bypass; and any morbidity. A minor injury is any other injury during RS.

RESULTS

The incidence of a major injury was not different between RS (0.3%; 2 of 602) and first-time sternotomy (0%; 0 of 1,274; p > 0.1). Incidence of a minor injury was 0.66% (4 of 602). No injury resulted in hemodynamic instability, neurologic injury, or death. Two patients (0.3%) required a nonemergent blood transfusion secondary to injury. (Nonemergent was defined as adminstration rate of less than 0.2 cc/kg/min and less than 10 cc/kg in total.) Femoral cannulation was performed in 4 of 602 RS cases (< 0.6%). Sternal wound infection was 0.5% (3 of 602); reoperation for postoperative bleeding was 1% (8 of 602). Median intensive care unit stay was 3 days (1 to 174); median hospital stay was 7 days (1 to 202). Hospital survival was 98%.

CONCLUSIONS

Repeat sternotomy can represent a negligible risk of injury and of subsequent morbidity or mortality. Therefore, the choice of management strategies for patients should not be affected by the need for RS.

Ventricular Assist Device Implantation Using a Right Thoracotomy

Most patients needing implantation of a ventricular assist device (VAD) require repeated sternotomy; some after cardiac surgery, and others later for heart transplantation. The purpose of this study was to establish the right thoracotomy technique as an alternative for VAD implantation to reduce repeated sternotomy-related morbidity and mortality. We performed a right thoracotomy in animals, preclinical cadaver fitting tests, and a clinical case. A total of 20 various animals underwent right thoracotomy for implantation of bi-VAD (BVAD, n = 17) and left VAD (LVAD, n = 3). The right chest cavity was entered through the fourth intercostal space with partial resection of the fifth rib. There was no procedure-related morbidity or mortality, except for one calf with right anterior leg paralysis. Preclinical fitting tests were performed on 7 human cadavers to observe the anatomical feasibility of BVAD cannulation from the right side of the heart. In humans, the ascending aorta, interatrial groove, right atrium, and main pulmonary artery were identified as optimal cannula insertion sites for BVAD implantation. A patient with cardiogenic shock underwent a right thoracotomy for implantation of an external LVAD. Cardiac function recovered after 3 weeks, and the device was successfully explanted through a repeat right thoracotomy. In conclusion, a right thoracotomy can be an alternative method to the standard median sternotomy for patients who need repeated sternotomy because of previous cardiac surgery, transplantation at a later date, or those with mediastinal infections.

Large Vessel — Sternum Adhesion After Cardiac Surgery; A Risk-Factor Analysis

PURPOSE

To study the clinical results of resternotomy in patients with dense and direct adhesion between the large vessels and the sternum, and define the morphologic features of the adhesion.

METHODS

Between 2000 and 2003, 67 patients with a history of cardiac surgery underwent median resternotomy. We studied each patient's profile and the measurements taken from preoperative computed tomography scans. We then conducted multivariate logistic regression analysis to determine the predictive morphologic features of adhesion between the large vessels and the sternum in these 67 patients.

RESULTS

Twenty (29.9%) of the 67 patients had direct adhesion between the large vessels and the sternum. Sternal re-entry was performed without injury to the large vessels in 18 (90%) but the aorta was injured in 2 (10%) patients, resulting in catastrophic hemodynamic disorder and operative death in one. Multivariate logistic regression analysis revealed that an extracardiac conduit and a high occupying rate of the aorta and pulmonary artery in the mediastinal space were significant morphologic factors.

CONCLUSION

The morphologic features of large vessels to sternal dense adhesion as possible risk factors for injury to the large vessels are the presence of an extracardiac conduit and a large ascending aorta or pulmonary artery in relation to the mediastinal space.

Plastron-trapdoor technique for direct-vision sternal re-entry

Repeat median sternotomy does not allow good access for retrosternal re-entry. Conversely, by using the plastron-trapdoor technique, which we describe in this report, the retrosternal tissues are dissected from the body of the sternum under direct vision, thus allowing relatively safe and wide exposure for retrosternal re-entry.