Role of Automated Suturing Technology in Minimally Invasive Aortic and Mitral Valve Surgery.

Minimally invasive cardiac surgery continues to evolve and expand as technology and surgeon experience develops. Among the barriers to the adoption of non-sternotomy minimally invasive valve surgery are the challenges associated with suture placement. Automated technology enables ergonomic remote suture placement that allows for reproducible results while shortening the learning curve. The objective of this review is to describe the latest advancements in automated suturing technology for minimally invasive valve surgery.

Navigating the Unexpected: Iatrogenic Aortic Injuries during Transcatheter Aortic Valve Replacement (TAVR).

The introduction of transcatheter aortic valve replacement (TAVR) has undeniably changed the landscape of valvular heart disease management over the last two decades. A reduction in complications through improvements in techniques, experience, and technology has established TAVR as a safe and effective alternative to surgical aortic valve replacement. However, it is important to consider the potential risks associated with TAVR and ways in which life-threatening complications can be identified and managed in a timely fashion. In this article, we review some catastrophic iatrogenic aortic injuries that are described in the literature and present a case of an acute iatrogenic type A aortic dissection that occurred during a transcatheter aortic valve replacement (TAVR). After valve deployment, a routine neurologic examination noted the new onset of a left-sided facial droop and upper extremity weakness. Urgent imaging revealed an extensive type A aortic dissection, and the patient was taken to the operating room for surgical repair. The coordination of our multidisciplinary team allowed for prompt recognition of her neurologic symptoms, urgent imaging, and timely transport to the operating room, all of which contributed to the successful management of this life-threatening procedural complication.

Aortic annulus rupture after transcatheter aortic valve replacement: successful management of a dangerous complication.

OBJECTIVE: Aortic annulus rupture remains one of the most fatal complications of TAVR. While attempts have been made to describe and predict this complication, the data remains insufficient without evidence-based guidelines for management of this rare complication. METHODS: Here we describe a series of 3 aortic annulus ruptures after TAVR which were managed successfully to hospital discharge. RESULTS: Patient 1 suffered annulus rupture during balloon valvuloplasty prior to TAVR. The patient became hypotensive, and echocardiogram showed pericardial effusion. The patient underwent pericardiocentesis which transiently improved the blood pressure, but bleeding continued. The patient was transitioned to an open surgical aortic valve replacement due to ongoing hemorrhage. The chest was left open with delayed closure on post-op day 2. The patient was discharged on post-op day 15. Patient 2 was undergoing TAVR valve expansion. The patient became hypotensive. An echocardiogram revealed pericardial effusion. Pericardiocentesis yielded 200 mL of blood. SURGIFLO (Johnson & Johnson Wound Management, Somerville, NJ) was injected into the pericardial space. Aortic root angiography confirmed no further contrast extravasation. A pericardial drain was left in place for 2 days, and the patient was discharged on post-op day 7. Patient 3 received a TAVR valve and post-placement dilation due to paravalvular leak. The echocardiogram showed a pericardial effusion. Pericardiocentesis was performed, yielding 500 cc of blood. The patient's healthcare proxy declined emergent surgery; thus, a pericardial drain was placed. No hemostatic agents were used, and drainage reduced over several hours. The drain was removed on post-op day 3, and the patient was discharged on post-op day 8. CONCLUSIONS: Based on the timelines in these three cases, and interventions used, the following steps may be employed in the event of annulus rupture: identification of hemodynamic instability, echocardiogram to confirm pericardial effusion, emergent pericardiocentesis, pericardial drain placement for evacuation of the pericardial space and use of hemostatic agents, repeat aortogram to rule out ongoing extravasation. If hemostasis is unable to be achieved and/or the patient becomes hemodynamically unstable at any point, rapid transition to emergent surgical management is necessary. This management strategy proved successful for this case series and warrants further investigation.

Transcatheter aortic valve replacement 23 years after heart transplant for aortic insufficiency.

BACKGROUND: Clinicians continue to expand the availability of transcatheter aortic valve replacement (TAVR) for patients who historically would have been ineligible for surgical aortic valve replacement. Historically, reoperative aortic valve surgery after transplant was immensely complicated and high risk due to the repeat sternotomy approach, and the immunosuppression in transplant patients. As heart transplant patients continue to live longer, patients are beginning to develop novo aortic pathology of the transplanted organ. In these patients, TAVR may be a valuable rescue therapy for those with de-novo aortic valve disease. CASE PRESENTATION: Here, we present a single case of a 70-year-old man with a history of heart transplant 23 years prior complicated by severe sternal infection and subsequent removal of his sternum. Additionally, this patient had a recent history of kidney transplant due to renal cell carcinoma necessitating nephrectomy. He subsequently developed progressive symptomatic aortic insufficiency and underwent a successful TAVR to treat his new aortic disease. CONCLUSIONS: To our knowledge, this represents only the second case report of TAVR for severe aortic insufficiency and one of the first reports of TAVR in a multiple organ recipient. TAVR may represent an important rescue therapy for post-transplant valve pathologies instead of high-risk reoperative surgical aortic valve replacement.

Infective endocarditis of quadricuspid aortic valve.

BACKGROUND: Infective endocarditis of the aortic valve is a relatively common disease presentation, with surgical intervention a mainstay of treatment in severe cases. Quadricuspid aortic valves are a rare spontaneous developmental anomaly that are more likely to be asymptomatic, and less likely to require a full valve replacement than their hypocuspid counterparts. However, there is very little literature addressing infective endocarditis of this valve variant. CASE PRESENTATION: This case report presents a case of infective endocarditis of a quadricuspid aortic valve that required replacement with a surgical bioprosthetic valve. The patient is a 30 year old male with a history of polysubstance use, upper extremity aneurysm, and prior tricuspid valve endocarditis. Surgical aortic valve replacement was performed with a 25 mm tissue valve via median sternotomy. CONCLUSIONS: The patient made a full recovery after surgical aortic valve replacement and a course of antibiotics and was discharged home without any complications. This supports that surgical aortic valve replacement is feasible and safe in patients with polycuspid aortic valve endocarditis.

Efficacy of Intraventricular Sponge Placement to Capture Debris in Aortic Valve Replacement.

Objective: Surgical aortic valve replacement (SAVR) carries the known risk of shedding debris into the left ventricle during valve leaflet excision and annulus debridement. Embolization of this debris may have devastating effects for the patient. Although surgeons have developed methods to mitigate this risk, no data exist as to their efficacy. Herein, we present the first study that evaluates the efficacy of a technique for capturing debris during SAVR. Methods: Our group conducted a prospective case series of 20 patients who underwent SAVR using the insertion of an intraventricular surgical sponge prior to valve leaflet excision and annulus debridement to capture debris. Surgical sponges were grossly, radiographically, and histologically examined for the presence of cellular and acellular debris to determine the efficacy of this technique. Results: Of the 20 surgical sponges analyzed, 15 specimens (75%) registered positivity for cellular and/or acellular debris. Seven sponges (35%) were grossly positive, 15 sponges (75%) were radiographically positive, and 4 sponges (20%) were histologically positive for calcified debris on examination. Conclusions: This is one of the few studies to objectively evaluate a method used to capture debris in SAVR procedures. Our results demonstrate a high frequency of debris captured within intraventricular surgical sponges and confirms the efficacy of this technique. While these data are promising, numerous additional approaches exist to capture debris, and a best practice standard should exist across the specialty.  In addition, this study does not address the clinical outcomes associated with this technique. To these ends, additional data and multicenter collaboration are required.

Novel Automated Suturing Technology for Minimally Invasive Mitral Chord Implantation: A Preclinical Evaluation Study.

OBJECTIVE: This study evaluated the ergonomics and time requirements of using a novel automated suturing and titanium fastener deployment technology for chordal replacement in human heart specimens in open and minimally invasive cardiac surgery (MICS) simulators. METHODS: Five cardiac surgeons used novel, manually powered expanded polytetrafluoroethylene (ePTFE) suturing devices to automate suture placement between mitral leaflets and papillary muscles in explanted cadaver hearts, along with customized titanium fastener delivery devices to secure suture and trim suture tails. This mitral chordal replacement test was conducted using surgical models simulating open and MICS mitral repair access. The study was approved by the institutional ethical board. RESULTS: After a brief introduction to this technique using plastic models, study surgeons performed 48 chordal replacements in human mitral valves, placing 18 in an open model and 30 in a right minithoracotomy model. The time range to complete a single chordal replacement was between 55 s and 8 min, with an overall mean duration of 3.6 ± 1.5 min. No difference in duration of implantation was recorded for the MICS and open sternotomy simulators used. Good control of suture delivery was reported in 95.8% (n = 46) of leaflet aspect of the sutures and in 100% (N = 48) of papillary muscle sutures. CONCLUSIONS: Automated mitral chordal ePTFE suturing simulated through open and MICS access demonstrated quality handling and accurate placement of sutures in human heart specimens. A clinical trial using this technology is currently ongoing. This innovation may present an important advance facilitating enhanced minimally invasive mitral valve repair.

Early Outcomes of Isolated Aortic Valve Replacement Through Right Anterior Minithoracotomy Using the Latest-Generation Biological Prosthesis.

OBJECTIVE: The aim of this study is to evaluate early and intermediate outcomes and hemodynamics of the latest-generation Trifecta valve implanted using right anterior minithoracotomy. METHODS: We performed a single-center, retrospective, observational study including 175 individuals who underwent isolated minimally invasive aortic valve replacement with the latest-generation Trifecta valves through a right anterior minithoracotomy between January 2016 and January 2019. Exclusion criteria for follow-up echocardiographic study included concomitant procedures, conversion to median sternotomy, and nonsurvival during the index admission. Analyses addressed implantation safety, 30-day and intermediate-term survival and hemodynamic performance of the valves. RESULTS: Overall, patients were followed with duration ranging from 0.5 to 3 years. Early (<30 days) mortality occurred in 2 patients (1.1%), and there were 9 (5.1%) late (>30 days) deaths. Early thromboembolic events and postoperative bleeding requiring reoperation occurred at a rate of 4.0% (n = 7) and 6.2% (n = 11), respectively. Overall in 175 patients who met inclusion criteria for the follow-up echocardiography study, mean gradients across all valve sizes were 41.3 ± 14.9 (standard deviation) mm Hg preoperatively and remained low at 7.2 ± 3.9 mm Hg with mean effective orifice area of 1.8 ± 0.5 cm2 on the last follow-up echo. There was 1 case of infective prosthetic endocarditis, which did not require valve explant. There were no reoperations due to valve-related problems during the study period. CONCLUSIONS: This is the largest series reporting on outcomes of the latest-generation Trifecta valve implanted using right anterior minithoracotomy. Our results demonstrate that this valve can be safely implanted via a minimally invasive approach with excellent early and intermediate outcomes and hemodynamic performance.

A Novel Subxiphoid Approach for Bilateral Internal Thoracic Artery Harvesting.

OBJECTIVE: Bilateral internal thoracic artery (BITA) bypass can enable more complete arterial revascularization procedures. Minimally invasive cardiac surgery (MICS) can offer significant patient benefits. New minimally invasive technology for sternal retraction and tissue manipulation is needed to enable ergonomic and reliable minimally invasive ITA harvesting. The goal of this research was to develop technology and techniques, along with experimental testing and training models, for a sternal-sparing approach to in situ BITA harvesting through a small subxiphoid access site. METHODS: This study focused on optimizing custom equipment and methods for subxiphoid BITA harvesting initially in a porcine model (19 pig carcasses, 36 ITAs) and subsequently in 7 cadavers (14 ITAs). RESULTS: Fifty consecutive ITAs were successfully harvested using this remote access approach. The last 20 ITA specimens harvested from the porcine model were explanted and measured; the average length of the free ITA grafts was 12.8 ± 0.9 cm (range 10.8 to 14.2 cm) with a mean time of 23.3 ± 5.2 minutes (range 13 to 25 minutes) for each harvest. CONCLUSIONS: Early results demonstrate that both ITAs can be reliably harvested in a skeletonized fashion in situ through sternal-sparing, small subxiphoid access in 2 experimental models. This innovative approach warrants further exploration toward facilitating complete arterial revascularization and the further adoption of minimally invasive coronary artery bypass graft surgery.

Routine Placement of Temporary Epicardial Pacing Leads Is Not Required After Minimally Invasive Aortic Valve Replacement.

OBJECTIVE: Our objective is to identify the incidence of urgent transvenous (TV) pacing wire placement following minimally invasive aortic valve replacement (mini-AVR). METHODS: This is a single-center, retrospective, observational study including 359 individuals who underwent isolated mini-AVR through right anterior mini-thoracotomy between January 2015 and September 2019. Patients were grouped according to avoidance or insertion of epicardial pacing wires, and further subdivided based on the requirement for postoperative emergent temporary TV pacing or permanent pacemaker (PPM) placement during the index admission. RESULTS: Two hundred forty-two (67.4%) had acceptable rate and no high-degree atrioventricular (AV) block prior to chest closure and did not have insertion of epicardial pacing wires. Of those patients, only 3 (1.2%) required emergent TV pacing and 6 (2.5%) required nonemergent TV pacing with or without PPM placement during the index admission. Sixty-two (17.3%) patients received only atrial epicardial pacing leads secondary to sinus bradycardia or junctional rhythm and 3 (4.8%) of those patients required PPM placement due to sick sinus syndrome and 1 (1.6%) patient required nonemergent TV pacing and PPM due to high-grade AV heart block. Fifty-five (15.3%) patients received ventricular leads due to high-grade AV heart block and 7 (12.7%) of those patients required PPM placement during the index admission. CONCLUSIONS: Temporary epicardial lead insertion is not routinely required in mini-AVR in patients with normal rate and acceptable AV conduction prior to chest closure. In the absence of epicardial ventricular lead insertion, the chance of requiring urgent TV pacing wire placement during the index admission is 0.99%.

Titanium Fastener Utilization During HeartMate 3 Left Ventricular Assist Device Implantation.

OBJECTIVE: The objective of this study was to investigate the feasibility of using titanium fasteners for securement of the inflow sewing ring during HeartMate 3 implantation. The secondary objective was to compare cardiopulmonary bypass and total operative times between the titanium fastener and hand-tied knot groups. METHODS: Clearance between the sewing ring and the HeartMate 3 device was assessed in vitro. Thirty-one patients undergoing HeartMate 3 implantation via median sternotomy at a single center from April 2017 to February 2018 were reviewed. The sewing ring was secured with hand-tied knots (n = 18) or titanium fasteners (n = 13). Cannulation strategy and implantation technique were otherwise identical between groups. Central arterial and venous cannulation was performed for cardiopulmonary bypass. The left ventricular apex was cored, and the sewing ring was attached with hand-tied knots or titanium fasteners. RESULTS: There was adequate clearance for the titanium fastener to secure the inflow sewing ring and then connect to the HeartMate 3 in vitro. The inflow sewing ring was successfully secured during HeartMate 3 implantation in the titanium fastener group. Cardiopulmonary bypass time was 75 and 92 minutes for the titanium fastener and hand-tied groups, respectively (P < 0.03). Total operative time was 177 and 193 minutes for the titanium fastener and hand-tied groups, respectively (P = 0.513). CONCLUSIONS: The inflow sewing ring of the HeartMate 3 was efficiently secured using titanium fasteners. Titanium fasteners resulted in shorter cardiopulmonary bypass times compared with the hand-tied group. There was no difference in total operative time.

Rapamycin inhibits the production of myofibroblasts and reduces corneal scarring after photorefractive keratectomy.

PURPOSE: Corneal stromal scarring partly involves the production of corneal myofibroblasts. The purpose of this study was to examine the effects of rapamycin (an inhibitor of the mammalian target of rapamycin [mTOR] pathway) on myofibroblast formation in vitro and in-vivo. METHODS: Human corneal fibroblasts were grown in culture and transformed into myofibroblasts using TGF-ß (2 ng/mL). The phosphorylation (activation) of the mTOR pathway was examined by immunoblotting. Cell proliferation with and without rapamycin was examined by thiazolyl blue tetrazolium bromide (MTT) assay and Ki67 staining. The expression of the myofibroblast differentiation marker smooth muscle actin (SMA) was examined by immunostaining and immunoblotting. The functional effects of rapamycin were measured using a gel contraction assay. For in vivo studies, 140 µm laser ablation was performed on rabbit corneas followed by subconjunctival rapamycin or vehicle. Corneal haze development was graded at 4 weeks, while the expression of myofibroblast markers was examined by immunostaining and immunoblotting. RESULTS: The TGF-ß activated the mTOR pathway with peak phosphorylation at 2 to 4 hours. Treatment of corneal fibroblasts with rapamycin reduced their proliferation by 46% compared to control. Rapamycin significantly inhibited TGF-ß-induced expression of myofibroblast markers (17.2% SMA positive cells with rapamycin compared to 69.0% in control). Rapamycin also significantly inhibited TGF-ß-induced collagen gel contraction. In the rabbit eyes treated with rapamycin, corneal haze development was significantly less compared to controls (0.75 ± 0.4 vs. 2.17 ± 0.7). CONCLUSIONS: Rapamycin appears to inhibit proliferation and differentiation of corneal myofibroblasts and, thus, may provide an effective therapeutic measure for preventing corneal scarring.