Sewing Ring Research Articles

THE “SANDWICH” TECHNIQUE IN MITRAL ANNULAR CALCIFICATION

Abstract Objective To assess the feasibility and safety of the “Sandwich” technique in case of massive mitral annular calcification (MAC). MAC is a multifactorial chronic disease and a challenging clinical entity to the surgeon: both respecting and resecting techniques have been developed, in order to prevent eventual annular ruptures. Methods Twelve patients underwent mitral valve replacement (MVR) between January and September 2023, mainly because of steno–insufficiency of the mitral valve, in presence of MAC. Their mean age was 76 ± 4.5, their BMI was 27.2 ± 2.8 and their surgery was mostly elective, except for one urgent active endocarditis; their mean EUROscore II was 8.2 ± 2.9. Results We performed 12 MVR with biological valve, through full sternotomy approach. The cardiopulmonary bypass and aortic cross–clamp time were 195 ± 57 and 155 ± 42 minutes respectively. We perform a double line suture respectful of the annular calcium, in order to reinforce the mitral annulus, before fixing the prosthesis. Surgical stiches on the anterior annulus were ordinarily put; on the posterior annulus, which is usually the most calcified part, a teflon band underneath the calcium was fixed as first, through separate prolene 2–0 U–stitches. Then the usual 2–0 ticron stitches with pledget were put between the posterior annulus and the atrial wall. Both 2–0 prolene and ticron were passed through the prosthesis sewing ring: prolene was placed more externally than ticron. No leakages were found, both intraoperative and postoperative. There were no in–hospital deaths. No strokes, thromboembolic or coronary complications were observed. Conclusions The “Sandwich” technique is reproducible, feasible and safe and it does not imply a long surgical learning curve. It is not a disruptive approach, avoiding annulus failure and it is respectful of the cardiac structures.

Predicted vs Observed Valve to Coronary Distance in Valve-in-Valve TAVR: A Computed Tomography Study

BackgroundPreprocedural computed tomography (CT) workup with assessment of virtual transcatheter heart valve-to-coronary ostia (VTC) distance and transcatheter heart valve-to-sinus (VTS) distances is recommended to assess the risk of coronary obstruction following valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR). ObjectivesThe authors sought to investigate the agreement of predicted VTC and VTS distances and observed post-TAVR anatomy on CT and their relationship with transcatheter heart valve (THV) expansion and deployment conditions. MethodsFifty-one patients who underwent a balloon-expandable ViV procedure were included in this study. The expansion of the THV stent frame was evaluated at 4 levels: THV inflow, surgical heart valve (SHV) sewing ring, SHV outflow, and THV outflow. Assessment of the VTC/VTS distances was performed on the pre-TAVR CT, and THV-to-coronary ostia and THV-to-sinus distances were assessed on the post-TAVR CT. ResultsFollowing the ViV procedure, the THV stent frame flared toward the outflow but was generally underexpanded at all levels, particularly at the SHV sewing ring level. Postdilatation impacted the extent of THV expansion, resulting in greater expansion than nominal balloon filling at all 4 THV levels (P < 0.001). Observed THV-to-coronary ostia distances were systematically larger than predicted by the VTC distance (mean difference 1.25 ±1.28 mm) in patients with nominal balloon filling but systematically smaller in case of postdilatation (mean difference −0.45 ± 0.52 mm). A similar relationship was observed between VTS and THV-to-sinus distance measurements. ConclusionsWith nominal balloon filling, VTC and VTS distances underestimate postprocedural distances due to THV frame underexpansion. However, postdilatation may lead to distances smaller than predicted due to THV overexpansion at the outflow level.

Computed tomography reference dimensions for identification of stented surgical mitral bioprostheses valve size

BackgroundSelection of the transcatheter heart valve size for a mitral valve-in-valve procedure is based on the type and manufacturer’s labelled size. However, accurate information of surgical heart valve (SHV) size may not be available in the patient’s medical record. The purpose of this study is to establish reference data for computed tomography (CT) dimensions of commonly used mitral SHV in order to determine the manufacturer’s labelled size from a cardiac CT data set. MethodsCT datasets of 105 patients with surgical mitral bioprosthesis and available manufacturer labeled datasets were included in the analysis. CT derived valve dimensions were assessed by two observers using multiplanar reformats aligned with the basal sewing ring. A circular region of interest was used in a standardized fashion to minimize influence of image acquisition and reconstruction parameters. Interobserver variability was assessed by Bland-Altman analysis. ResultsThe CT-derived dimensions were stratified by valve size and type, and SHV properties were demonstrated for 5 common valve types. Variability of measurements was small and inter-observer limits of agreement were narrow. Stratified by SHV type, no overlap was noted for CT-derived dimensions among different SHV sizes . A reference table of CT characteristics of surgical mitral bioprosthesis types was created. ConclusionThe study provides reference CT data for determining the manufacturers’ labeled SHV size across a range of commonly used mitral SHVs. The findings will be important to help identify types of surgical mitral bioprosthesis utilizing CT characteristics for patients without SHV size documentation.

Transesophageal Echocardiography (TEE)-Guided Paravalvular Leak (PVL) Closure: Expanding Horizons Beyond Operating Room

AbstractParavalvular leak (PVL) is a common, yet challenging entity occurring due to dehiscence of the annular tissue around the prosthetic valve, resulting in regurgitation of blood retrogradely. Although any prosthetic valve can be subjected to the risk of developing PVL, it is most commonly reported with the mitral valve followed by the aortic valve. The incidence of mitral PVL is around 7 to 17%, whereas with the aortic valve it is 5 to 10%. Symptomology can vary from asymptomatic patients with mild PVL to disabling symptoms pertaining to heart failure and hemolysis. TEE plays a pivotal role in the overall assessment along with procedural guidance for their closure. Multiple two-dimensional (2D) imaging views are required to scan the entire sewing ring diameter of a prosthetic valve. Three-dimensional (3D) TEE can give crucial information such as the number, size, shape, and circumference of the defects. 3D mitral en face view can give anatomical localization of the defect. During the procedure, TEE can assist in the confirmation of the position of the guidewire through the defect and not through the prosthetic valve. It also helps to conform to the adequate positioning of the vascular plug device and unrestrictive movement of the native prosthetic heart valve. TEE when combined with fluoroscopy can help in real-time guidance of passage of the guidewire and transcatheter device in relation to the prosthetic valve. Recently, Ahmed et al have named this technology as “Fusion Technique,” where they have combined real-time 2D and 3D TEE with fluoroscopy to facilitate the closure of PVL. Now that the time of minimally invasive surgery has taken over conventional surgery and fast tracking and enhanced recovery after surgery (ERAS) is the need of the moment, percutaneous PVL closure is preferred over surgical PVL closure. A study done by Gakrinho et al showed that percutaneous PVL closure has a reasonable success rate along with a low complication rate and the results are comparable to surgical treatment in high-risk patients. We hereby share our experience of the successful closure of PVL via the transcatheter technique using various 2D and 3D techniques.

New tools in minimal invasive aortic valve surgery: case report

Video 1 This is a standard case of aortic valve regurgitation of a 65 years old female, with known disease since 2008 and symptomatic in functional class II. At the echo valved looked bicuspid. The operations scheduled was aortic valve replacement with a tissue valve (actually was a CE num 19) through a J sternotomy. An innovative device composed by two staples, called RAM® and the other SEW-EASY®, was intended to use for suturing the prosthesis. Also, the use of another well-known device, aimed to tied suture, called COR-KNOT® was established. After central cannulation and selective delivery of cardioplegia, aortic cusps are resected. With the RAM® device the two ends of the tread with the Teflon pledget are passed equidistant in the aortic annulus, after previous loading of the stitch in to the device. Then, with the called SEW-EASY® device, stitches are also symmetrically passed thought the sewing ring of the prosthesis. After the prosthesis is parachuted, the COR-KNOT® device was used to finally tied the stitches. The intraoperative echo showed well positioned prosthesis, without paravalvular leak.

Multimodality Cardiac Imaging for Procedural Planning and Guidance of Transcatheter Mitral Valve Replacement and Mitral Paravalvular Leak Closure.

Transcatheter mitral valve interventions are an evolving and growing field in which multimodality cardiac imaging is essential for diagnosis, procedural planning, and intraprocedural guidance. Currently, transcatheter mitral valve-in-valve with a balloon-expandable valve is the only form of transcatheter mitral valve replacement (TMVR) approved by the FDA, but valve-in-ring and valve-in-mitral annular calcification interventions are increasingly being performed. Additionally, there are several devices under investigation for implantation in a native annulus. Paravalvular leak (PVL) is a known complication of surgical or transcatheter valve implantation, where regurgitant flow occurs between the prosthetic sewing ring and the native mitral annulus. We sought to describe the role and applications of multimodality cardiac imaging for TMVR, and PVL closure, including the use of Cardiovascular Computed Tomography Angiography and 3-Dimensional Transesophageal Echocardiography for diagnosis, prosthetic valve evaluation, pre-procedural planning, and intraprocedural guidance, as well as evolving technologies such as fusion imaging and 3D printing.

Conversion of the HVAD Left Ventricular Assist Device to the Centrimag Using a Customized Apical Plug

Left ventricular assist device thrombosis is a potentially life-threatening complication often managed acutely with device exchange. In the absence of modifiable risk factors recurrent thrombosis can occur. Recent changes in the heart allocation policy have reduced left ventricular assist device complications from top priority to status 3. In this report we present a patient with recurrent left ventricular assist device thrombosis. Given no modifiable risk factors and recurrence of thrombosis, the HeartWare HVAD ((Medtronic, Minneapolis, MN)) was converted to a temporary Centrimag device device (Abbott, Abbott Park, IL) using a novel plug through the existing sewing ring. With status 2 listing the patient was successfully transplanted on postoperative day3.

Minimally invasive pulmonary valve replacement via left anterior minithoracotomy.

ABSTRACT Pulmonary valve replacement is one of the most common indications for reoperation in adults with congenital heart disease. Finding an alternative to repeat median sternotomy may facilitate recovery and shorten hospital stay. We present our technique of left anterior minithoracotomy for pulmonary valve replacement.

Implantation of a HeartMate 3 ventricular assist device in a 21‐kg pediatric patient with Fontan failure

The HeartMate 3 (HM3) ventricular assist device (VAD) is gaining popularity in adults due to a favorable risk profile. However, reports of HM3 use in children are limited, potentially due to concerns with device size. Here we report the successful use of an HM3-VAD as a bridge to transplantation in a 21 kg (BSA 0.84), an 8-year-old male child with Fontan failure on home inotropes. Urgent VAD implantation was performed. The standard adult sewing ring was used. The tricuspid valve and papillary muscles were completely excised from the ventricular cavity to prevent inflow obstruction. The pump was placed in the left pleural space. Outflow graft and driveline implantation were routine. VAD function appeared excellent with a reduction in Fontan pressures and improved kidney and liver function. Reoperation was required once to rule out tamponade and twice to evacuate a recurrent right hemothorax. The patient was discharged 3 months later in good condition and underwent successful heart transplantation 10 months after VAD placement. This report demonstrates the feasibility of HM3-VAD implantation in a 21-kg Fontan patient, suggesting HM3 size is not a prohibitive limitation at this weight.

Interventricular septal hematoma complicating placement of a ventricular assist device in an infant and support with bi-atrial cannulation.

Interventricular septal hematoma complicating placement of a ventricular assist device in an infant and support with bi-atrial cannulation.

Experimental Study of the Tissue Repair of Neo-Esophagus After Esophageal Muscularis Resection.

Attempts have been made to observe the tissue repair of neo-esophagus after esophageal muscularis resection and to investigate possibility of the regeneration repair of esophageal muscularis resection in neo-esophagus. Sixteen pigs were divided into two groups: group A and group B. Pigs in group A were performed with the partial resection of mere esophageal muscularis propria reserved mucosa muscle layer in a segment of thoracic esophagus. Pigs in group B were performed with nitinol composite artificial esophagus with polyester sewing rings replacement a segment of thoracic esophagus resection. Pigs in the two groups were performed with euthanasia at the following times: 2, 4, 6, and 12 months for postmortem analysis, which demonstrated the absence of esophageal muscularis regeneration in the specimens that were sampled from different time points. Reserved mucosa muscle layer did not show hyperplasia to repair coloboma of esophageal muscularis propria deletion in group A. These results suggest that after esophageal muscularis resection, including mucosa muscle layer or esophageal muscularis propria, the coloboma of esophageal muscularis was repaired with connective tissue filling quickly. It would be very difficult for the regeneration repair of esophageal muscularis in neo-esophageal tissue structure after esophageal muscularis resection.

Less Is More: Sutureless Aortic Valve Replacement Into Valsalva Graft

Redo surgery is often high risk, due to distorted patient anatomy and longer cardiopulmonary bypass and aortic cross-clamp times. It can also be more technically challenging, due to previous surgeries and the limitations that these impose. One such case that resulted in a previously unreported procedural solution is presented: sutureless valve into a previously straight Valsalva graft and aortic valve bioprosthesis. This high-risk elderly male presented with Streptococcus salivarius infective endocarditis in October 2017. Although initially medically managed, this resulted in progressive valvular destruction and aortic insufficiency, with subsequent heart failure and severe aortic regurgitation within months. This off-label operative technique included resection of the bioprosthetic aortic valve leaflets and deployment of the sutureless valve within the previous sewing ring. The struts were re-fashioned for added security, extra sutures were taken and increased inflation pressures were applied in order to achieve a well-seated valve. This strategy ultimately obviated the need for a redo Bentall's procedure in an otherwise high-risk patient who went on to have an uneventful postoperative course and uncomplicated recovery. This case demonstrates a safe alternative valve replacement strategy that can be considered in patients for whom a redo Bentall's procedure is high risk.

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

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. 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. 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). 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.

Surgical Technique for Redo-Sternotomy Sparing Heartware HVAD Exchanges

Prolonged support times in bridge to transplant patients, as well as the growing number of destination patients lead to increased rates of LVAD pump exchanges for pump thrombosis, pump infections, and other device problems. We describe our surgical approach for pump exchanges in patients supported with the Heartware HVAD ventricular assist device. Pump exchanges are performed via a limited thoracotomy in the fourth, fifth, or sixth left intercostal space with cardiopulmonary bypass support. The apical sewing ring as well as the outflow graft are reused in order to limit the complexity of the procedure and minimize the need for extensive dissections. Given the significant reduction in surgical complexity and invasiveness, the described technique should be considered the standard approach for Heartware HVAD patients with device complications necessitating isolated pump exchanges.

Bioprosthetic Valve Fracture During Valve-in-valve TAVR: Bench to Bedside.

Valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) has been established as a safe and effective means of treating failed surgical bioprosthetic valves (BPVs) in patients at high risk for complications related to reoperation. Patients who undergo VIV TAVR are at risk of patient-prosthesis mismatch, as the transcatheter heart valve (THV) is implanted within the ring of the existing BPV, limiting full expansion and reducing the maximum achievable effective orifice area of the THV. Importantly, patient-prosthesis mismatch and high residual transvalvular gradients are associated with reduced survival following VIV TAVR. Bioprosthetic valve fracture (BVF) is as a novel technique to address this problem. During BPV, a non-compliant valvuloplasty balloon is positioned within the BPV frame, and a highpressure balloon inflation is performed to fracture the surgical sewing ring of the BPV. This allows for further expansion of the BPV as well as the implanted THV, thus increasing the maximum effective orifice area that can be achieved after VIV TAVR. This review focuses on the current evidence base for BVF to facilitate VIV TAVR, including initial bench testing, procedural technique, clinical experience and future directions.

70. Surgical mitral valve replacement with modified Melody valve in children

Objective We describe a case of mitral valve (MV) replacement using modified Melody valve implantation. Methods A 2.5 year-old girl,with a history of ALCAPA repair in April 2012, had undergone MV repair by ring annuloplasty at 1 year of age. She came back with severe MV stenosis (mean gradient, 8 mmHg) and regurgitation. She had a hugely dilated left atrium and a MV annulus of 14 mm. She, then, underwent surgical MV replacement with a modified Melody valve. Results The Melody valve was prepared before the cardiopulmonary bypass. The procedure included stent shortening and adding a bovine pericardial sewing ring. Through a trans-septal approach, the previous MV ring was removed, the pericardial ring patch of the Melody valve was secured to the mitral annulus and the ventricular end of the valve was fixed to the posterior–inferior wall of the left ventricle. The prosthesis was then inflated to size 16 mm. Testing of the valve showed good leaflet coaptation. The atrial septum was closed by fenestrated (4 mm) bovine pericardial patch. TEE showed good valve function with a tiny paravalvular leak and no left ventricular outflow obstruction. The pulmonary veins were also unobstructed. Conclusions The modified Melody valve is a viable option for children MV annular diameters, providing a valid alternative to existing prostheses. The technique is relatively easy and the short term result is very good. This prosthesis will be particularly attractive if maintaining competence after subsequent dilations as the child grows.

Coronary ostial compromise in aortic valve replacement: an avoidable complication.

We sought to determine the incidence of hospital death due to surgical compromise of the coronary ostia in aortic valve replacement. The mechanism of coronary ostium blockage was also investigated. A retrospective review was conducted of prospectively collected clinical data and autopsy findings in 322 patients who died in hospital after aortic valve replacement with or without concomitant procedures in a single institution from January 1998 to March 2013. Over the 15-year period, more than 17 surgeons performed 7507 aortic valve replacements with or without other procedures. The mean age of the patients was 70.8 ± 11.78 years and 63% were male. Bioprosthetic valves were used in 75%, mechanical valves in 24.7%, and homografts in only 0.3%. Early mortality for all patients (combined, emergency, and redo procedures) was 4.29% (mean logistic EuroSCORE 10.7). There were 322 deaths after procedures involving the aortic valve. Autopsy examinations were carried out in all patients and showed that 3.4% (n = 11) of deaths were at least partly attributed to encroachment on one or both coronary ostia. Causes of ostial compromise included the valve sutures, the valve sewing ring, and the aortotomy suture line. Coronary ostial compromise in aortic valve replacement is a very rare but real problem occurring in at least 0.15% of aortic valve replacements and contributing to or directly causing one in every 29 aortic valve replacement deaths. Surgeons should have a high level of awareness of the risk of this rare but fatal and avoidable complication.

Neo-annulus: a reference plane in a surgical heart valve to facilitate a valve-in-valve procedure.

To determine the level of the narrowest plane (neo-annulus) of a surgical heart valve (SHV), which could be used for sizing and securing a transcatheter heart valve (THV) during a valve-in-valve (VIV) procedure and define its relationship with the fluoroscopic markers of the SHV. In the native aortic valve, the aortic annulus is used as a reference plane for sizing and deployment of THV as it provides the narrowest dimension to securely anchor the THV. However, the reference level for different models of SHV that are currently treated by a VIV procedure remains unknown. We studied 13 aortic SHVs from all major heart valve manufacturers (labeled size 21, 22, or 23). A 26cc valvuloplasty balloon was inflated with contrast within each SHV under fluoroscopy to achieve a 'waist'. The level of the 'waist' was compared with the SHV and its fluoroscopic markers to identify the level of the neo-annulus. In all SHVs tested, the balloon 'waist' or 'neo-annulus' was at the level of the sewing ring. When the fluoroscopic marker of the SHV was the sewing ring, the level of the neo-annulus was also at that level, irrespective of supra-annular or intra-annular design. However, when the fluoroscopic marker was the stent frame, the relationship between the fluoroscopic marker and the level of the neo-annulus was different for supra-annular and intra-annular designs. This correlation was not possible in two models of SHV as neither the stent nor the sewing ring was radio-opaque. We have demonstrated that the narrowest portion of all SHVs is at the level of its sewing ring, which can be identified fluoroscopically and should be used as a reference level during a VIV procedure.

Minimally invasive access for central extracorporeal life support: how we do it.

Central extracorporeal life support (ECLS) is an effective treatment method of cardiogenic shock patients with or without lung failure. However, complications like infection and bleeding are common. The classical implantation approach requires full sternotomy, mobilization of the heart, with the well-known risks of bleeding and mediastinal infections. We present our minimally invasive technique for central ECLS through a nonsternotomy incision. Minimized right-sided thoracotomy is performed. Flexible arterial and venous cannulas are tunneled toward the right thoracotomy incision through the eighth intercostal space. A sewing ring is secured to the right atrium and a tube graft is anastomosed to the ascending aorta. Following full-dose heparinization, the arterial cannula is inserted with the tip into the vascular graft of the ascending aorta and the venous cannula via the ring into the right atrium. After meticulous deairing, the central ECLS is set at full flow.

Invited Commentary

It would be easy to dismiss the study by Ellensen and colleagues [1Ellensen V.S. Andersen K.S. Vitale N. Davidsen E.S. Segadal L. Haaverstad R. Acute obstruction by pannus in patients with aortic Medtronic-Hall valves: 30 years of experience.Ann Thorac Surg. 2013; 96: 2123-2128Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar] as one of only historical interest, given that the Medtronic-Hall valve is no longer in use. The valve itself is an elegant design but is not relevant in today's “bileaflet world.” This comprehensive data set, however, gives us insight into a complication of mechanical valves common to all in character, albeit uncommon in occurrence: pannus formation.The incidence of pannus causing acute dysfunction in this study was 0.7/1,000 patient-years. This may be something of an underestimate, given that some pannus might occur causing stenosis without overt valve failure, even given a single-disc design. It is also conceivable that differences in the composition of the sewing rings could impact its development. Still, these data give us a reasonable estimate of the risk of pannus formation in the setting of a mechanical valve, a complication I always mention to a patient choosing a prosthesis but one for which I have not had handy number.The findings in this study also alert us to the serious nature of this complication, with one-quarter of individuals dying before surgical intervention could be accomplished and 2 dying during the reoperative procedure, for an overall mortality rate of 33%. It is unfortunate that the only risk factor identified is an unmodifiable one: female gender.Unfortunately, the details of suture technique, including use or nonuse of pledgets, were incomplete as was information on supraannular vs intraannular implantation, so the authors cannot give us technical advice for prevention. This leaves us with only the admonition to proceed without delay to definitive diagnostic and therapeutic measures when the diagnosis is suspected. Surely, that is of value to us all. It would be easy to dismiss the study by Ellensen and colleagues [1Ellensen V.S. Andersen K.S. Vitale N. Davidsen E.S. Segadal L. Haaverstad R. Acute obstruction by pannus in patients with aortic Medtronic-Hall valves: 30 years of experience.Ann Thorac Surg. 2013; 96: 2123-2128Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar] as one of only historical interest, given that the Medtronic-Hall valve is no longer in use. The valve itself is an elegant design but is not relevant in today's “bileaflet world.” This comprehensive data set, however, gives us insight into a complication of mechanical valves common to all in character, albeit uncommon in occurrence: pannus formation. The incidence of pannus causing acute dysfunction in this study was 0.7/1,000 patient-years. This may be something of an underestimate, given that some pannus might occur causing stenosis without overt valve failure, even given a single-disc design. It is also conceivable that differences in the composition of the sewing rings could impact its development. Still, these data give us a reasonable estimate of the risk of pannus formation in the setting of a mechanical valve, a complication I always mention to a patient choosing a prosthesis but one for which I have not had handy number. The findings in this study also alert us to the serious nature of this complication, with one-quarter of individuals dying before surgical intervention could be accomplished and 2 dying during the reoperative procedure, for an overall mortality rate of 33%. It is unfortunate that the only risk factor identified is an unmodifiable one: female gender. Unfortunately, the details of suture technique, including use or nonuse of pledgets, were incomplete as was information on supraannular vs intraannular implantation, so the authors cannot give us technical advice for prevention. This leaves us with only the admonition to proceed without delay to definitive diagnostic and therapeutic measures when the diagnosis is suspected. Surely, that is of value to us all. Acute Obstruction by Pannus in Patients With Aortic Medtronic-Hall Valves: 30 years of ExperienceThe Annals of Thoracic SurgeryVol. 96Issue 6PreviewAcute dysfunction of mechanical aortic valve prostheses is a life-threatening adverse event. Pannus overgrowth, which is fibroelastic hyperplasia originating from the periannular area, is one cause of dysfunction. The aim of this study was to determine the annual incidence of readmittance resulting from acute obstruction caused by pannus during 30 years of observation in patients with Medtronic-Hall aortic valve prostheses and to analyze the risk factors associated with pannus development. Full-Text PDF