New Insights Into Unicuspid Aortic Valve Disease in Adults: Not Just a Subtype of Bicuspid Aortic Valves

Current evidence of unicuspid aortic valve in young adults: A systematic review and metanalysis

Unicuspid aortic valve (UAV) is a rare congenital valvular anomaly, often misdiagnosed as the more prevalent bicuspid aortic valve (BAV). The aim of this study was to explore demographic, clinical characteristics, diagnosis, surgical options, short and long term outcomes of young adults with UAV. A systematic review and meta-analysis of literature were conducted for studies (1971-2024) including patients (≥ 14 years old) with diagnosis of UAV. Among the 2953 studies retrieved, 67 case reports, 6 case series (n = 130) and 13 retrospective studies (n = 918), were included in the analysis. Data from retrospective studies were aggregated using a random effects model for estimating the pooled risk ratio and mean difference. UAV is mostly unicommissural in adults (mean age 36 years old at diagnosis, 76-79 % males). The most common conditions associated in UAV patients were aortic coarctation (from 3.8 to 12 %), ventricular septal defect (3 %) and Turner syndrome (3 %). In general, the diagnosis was performed with TTE and confirmed with TEE (+/- 3D-TEE). The most common types of surgery were AVR. Dilated ascending aorta was described in 44 % and 35 % of retrospective studies and case reports, respectively. Concomitant ascending aorta replacement/repair was reported 38 % and 27 % of retrospective studies and case reports, respectively. Overall survival was reported in 3 studies, ranging from 95 to 98 % at 10 years. UAV should be considered a separate entity from BAV. Further investigations with regards to the possibility of a familial incidence, associated histopathological changes in the aorta, and ideal follow up and intervention are needed.

Case report: unravelling the puzzle of unicuspid aortic valve with multimodality imaging

Background

Unicuspid aortic valve (UAV) represents a rare congenital anomaly characterized by two subtypes: acommissural unicuspid aortic valve and unicommissural unicuspid aortic valve. Acommissural UAV is often diagnosed and corrected during the neonatal period due to haemodynamic instability. Unicommissural UAV leads to aortic stenosis (AS) in early adulthood. The diagnostic challenge associated with UAV primarily stems from its eccentric orifice opening and valvular calcification, resulting in difficult visualization of the commissures and localization of the orifice plane. This case report aims to demonstrate the unique morphological features of UAV through a comprehensive analysis using multimodality imaging.

Case summary

A 61-year-old woman presented to the emergency department for recurrent episodes of dyspnoea. Severe AS was diagnosed on transthoracic echocardiography (TTE) by Doppler haemodynamic measurement. However, follow-up transesophageal echocardiography (TEE) and CT transcatheter aortic valve replacement showed moderate AS by planimetry. Following this, patient was monitored closely, but her dyspnoea kept worsening. Cardiovascular magnetic resonance (CMR) was performed due to persistent dyspnoea, identifying UAV with eccentric loophole orifice with unicommissural attachment and opposite free leaflet edge. The patient was managed medically.

Discussion

TTE is the test of choice for AS that defines valvular morphology by direct visualization and grades the severity by haemodynamic measurement. However, the accuracy of TTE can be limited by poor acoustic windows and heavy valvular calcification. TEE measures aortic valve area (AVA) by planimetry that requires accurate localization of the AV orifice plane. Similarly, it applies to multi-detector computed tomography (MDCT). While CMR is expensive and mainly available in tertiary centres, it can provide additional information when there is discordance.

Unicuspid Aortic Valve in Patients Undergoing the Ross Procedure

BACKGROUND

The prevalence and outcomes of the unicuspid aortic valve (UAV) in patients undergoing the Ross procedure have been strongly underreported in the current literature. We sought to evaluate this in comparison with bicuspid (BAV) and tricuspid valve (TAV) in our Ross cohort.

METHODS

This was a retrospective observational study of patients undergoing the Ross procedure at 2 dedicated centers between 2009 and 2020. Primary end points were the risks of midterm autograft reoperation and the onset of at least moderate aortic regurgitation during follow-up. The secondary end point was to compare the perioperative outcomes between the groups.

RESULTS

Included in the analysis were 286 patients, of those 39% with UAV, 52% with BAV, and 9% with TAV. UAV patients were operated on at the youngest age (P < .001) and more often for a combined hemodynamic aortic valve pathology (P = .02). They had the largest aortic root dimensions: annulus (P = .01), Valsalva sinuses (P = .11), sinotubular junction (P = .001), and ascending aorta (P < .0001). The risks of reoperation (P = .86) and the onset of aortic regurgitation (P = .75) were comparable among the groups over the follow-up of 4.1 years. There was no difference in perioperative outcomes.

CONCLUSIONS

UAV is a separate unit characterized by a distinct hemodynamic pathology and generated aortopathy. It is not associated with a higher risk of reoperation or new onset of aortic regurgitation after the Ross procedure in the midterm postoperatively. At the current state, UAV remains acceptable for the Ross procedure.

Comparison of bicuspidization and Ross procedure in the treatment of unicuspid aortic valve disease in adults – Insight from the AVIATOR registry

Background

Unicuspid aortic valve (UAV) is the second most common underlying cause of aortic valve dysfunction in young adults after the bicuspid valve. The valve may be replaced (for example by pulmonary autograft) or repaired using the bicuspidization technique. The aim of our study was to compare short- and mid-term outcomes of Ross procedure with bicuspidization in patients with severe UAV dysfunction.

Methods

This was a multi-center retrospective observational cohort study comparing data from two dedicated Ross centers in the Czech Republic with bicuspidization outcomes provided by AVIATOR registry. As for the Ross group, only the patients with UAV were included. Primary endpoint was mid-term freedom from reintervention. Secondary endpoints were mid-term freedom from major adverse events, endocarditis and pacemaker implantation.

Results

Throughout the study period, 114 patients underwent the Ross procedure (years 2009-2020) and 126 patients underwent bicuspidization (years 2006-2019). The bicuspidization group was significantly younger and presented with a higher degree of dyspnea, a lower degree of aortic valve stenosis and more often with pure regurgitation. The primary endpoint occurred more frequently in the bicuspidization group than in the Ross group – 77.9 vs. 97.9 % at 5 years and 68.4 vs. 75.2 % at 10 years (p < 0.001). There was no difference in secondary endpoints.

Conclusion

Ross procedure might offer a significantly lower mid-term risk of reintervention than bicuspidization in patients with UAV. Both procedures have comparable survival and risk of other short- and mid-term complications postoperatively.

Surgical Management of Complex Aortic Valve Disease in Young Adults: Repair, Replacement, and Future Alternatives

The ideal aortic valve substitute in young adults remains unknown. Prosthetic valves are associated with a suboptimal survival and carry a significant risk of valve-related complications in young patients, mainly reinterventions with tissue valves and, thromboembolic events and major bleeding with mechanical prostheses. The Ross procedure is the only substitute that restores a survival curve similar to that of a matched general population, and permits a normal life without functional limitations. Though the risk of reintervention is the Achilles' heel of this procedure, it is very low in patients with aortic stenosis and can be mitigated in patients with aortic regurgitation by tailored surgical techniques. Finally, the Ozaki procedure and the transcatheter aortic valve implantation are seen by many as future alternatives but lack evidence and long-term follow-up in this specific patient population.

Unicuspid aortic valve: a rare congenital anomaly

Unicuspid aortic valve (UAV) is a rare congenital aortic valve anomaly. It has two subtypes and often is associated with aortic valve dysfunction and corresponding clinical presentations. Echocardiography is the first choice of diagnostic method for UAV. Three-dimensional echocardiography has played an increasingly important role in diagnosis, intraprocedural guidance, and post-procedural assessment in recent years. There remain challenges in distinguishing UAV from bicuspid aortic valve (BAV) or tricuspid aortic valve (TAV). Misdiagnosis is most resulted from raphes or leaflet calcifications. Multi-modality imaging has obvious advantages over single-modality imaging and is crucial for UAV diagnosis. Accurate identification of aortic valve morphology is important to choose the best treatment. Aortic balloon valvoplasty, surgical valvotomy, commissurotomy, Ross procedure, surgical valve repair and surgical replacement are most common treatment modalities of UAV. In this review, we aim to discuss UAV including epidemiology, definition, classification, diagnostic importance and necessity, valvular function, clinical presentation, associated disorders, non-invasive diagnostic modalities and therapeutic approaches.

Ross operation after failure of aortic valve repair

Background

Repair failure remains one of the most important complications of aortic valve reconstruction. Young patients might benefit from a Ross procedure in such a scenario, provided it can be performed safely and with adequate durability. The aim of this study was to assess the safety and clinical outcomes of a Ross operation following a failed repair.

Methods

Between 1996 and 2019, 80 patients (male, 76%; mean age, 31±13 years) underwent a Ross procedure after a median of 6.6 (1.7-15.9) years following an initial aortic valve repair. The previous valve repair was performed for unicuspid (53%), bicuspid (39%), tricuspid (7%), and quadricuspid morphology (1%). Median follow-up after the Ross operation was 2.8 (0.964-13.25) years, mean 5±5 years (92% complete).

Results

Median cardiopulmonary bypass and cross-clamp times were 144 [106-154] minutes and 98 [79-113] minutes, respectively. Thirty-two patients (40%) required a concomitant procedure, most commonly, an ascending aortic replacement (n=23). There were no peri-operative deaths, myocardial infarctions, or neurological complications. There was one late death from a non-cardiac cause. At 10 years, overall survival was 99%±1%, similar to that of an age- and gender-matched population. Nine patients required re-intervention after their Ross procedure (five on the autograft and four on the pulmonary conduit). The autograft re-interventions were valve-sparing procedures in all patients. The cumulative incidence of re-intervention on the autograft at 8 years was 5.1%±3.1%.

Conclusions

The stepwise strategy of an initial valve repair followed by Ross operation represents a safe and valid option for failed aortic valve repair. It is associated with low peri-operative morbidity. Mid-term survival is excellent, similar to that of a matched general population. The probability of re-intervention after the Ross procedure appears similar to that of a primary Ross operation, deeming it a warranted consideration in cases of failed aortic valve repair.

Considerations in the Surgical Management of Unicuspid Aortic Stenosis

Unicuspid aortic valve (UAV) stenosis is a rare condition accounting for 5% of non-rheumatic aortic stenosis. The diagnosis can be difficult to make prior to surgical intervention and transesophageal echocardiography has been demonstrated to be more accurate in making the diagnosis compared to transthoracic echocardiography. The presence of a posteriorly located aortic orifice on the short-axis views, with one or two visible raphe anteriorly; the absence of commissures (acommissural); or the presence of a lone commissure (unicommissural) between the left and noncoronary, or the left and right cusps suggests the diagnosis. Patients with UAV are predominantly males and present with stenosis about a decade earlier than those with the more prevalent bicuspid aortic valves (BAV). They more commonly present with aortic annular dilatation and have fewer comorbidities at presentation compared to patients with BAV. Surgical management of UAV stenosis includes aortic valve replacement through standard open heart surgery or percutaneous transcatheter aortic valve replacement (TAVR), aortic valve repair either by bicuspidization, tricuspidization or trileaflet reconstruction, or the Ross procedure. Patients with UAV stenosis require less concomitant coronary or other cardiac procedures when they need surgical intervention, but are about a decade younger at the time of their death. UAV stenosis is a distinct congenital anomaly with a different natural course than BAV. Surgical management should be individualized based on the patient's age at presentation, aortoannular anatomy, and associated cardiac conditions.

Narrative review of the contemporary surgical treatment of unicuspid aortic valve disease

Unicuspid aortic valve disease (UAVD) is a frequent and long-lasting challenge for adult congenital heart disease centers. UAVD patients become usually symptomatic in their twenties or thirties and require a surgical treatment plan which should respect their complete lifespan combined with an adequate quality of life. Unfortunately, all current surgical strategies of congenital aortic valve disease bear some important limitations: (I) Aortic valve replacement using bioprosthetic valves is associated with early structural degeneration and leads frequently to re-operations. (II) Mechanical valves are commonly associated with lifelong risk of severe bleeding due to oral anticoagulation. (III) Using a pulmonary autograft (i.e., Ross procedure) for aortic valve replacement is associated with excellent long-term results in non-elderly patients. However, failure of pulmonary autograft or pulmonary homograft may require re-operations. (IV) Aortic valve repair or Ozaki procedure is only performed in a few heart centers worldwide and is associated with a limited reproducibility and early patch degeneration, suture dehiscence or increased risk of endocarditis. In contrast to degenerative tricuspid aortic valve disease, UAVD remains relatively understudied and reports on UAVD treatment are rare and usually limited to retrospective single-center observations. For this review, we searched PubMed for papers in the English language by using the search words unicuspid aortic valve, congenital aortic valve, Ross procedure, Ozaki procedure, aortic valve repair, mechanical/bioprosthetic aortic replacement, homograft. We read the abstracts of relevant titles to confirm their relevance, and the full papers were then extracted. References from extracted papers were checked for additional relevant reports. This review summarizes current surgical treatment strategies for UAVD including aortic valve replacement using bioprosthetic or mechanical valves, homografts, pulmonary autografts (i.e., Ross procedure) and aortic valve repair techniques for UAV. Furthermore, Ozaki procedure will be discussed.

Unicuspid aortic valve: Case series and review

A unicuspid aortic valve is a very rare valvular lesion. Its physical manifestations vary and are associated with other cardiovascular abnormalities such as aortic stenosis/insufficiency and aortopathy. Echocardiography remains the modality of choice, with computerized tomography or cardiac magnetic resonance used as adjunctive imaging. Herein, we present a case series of three patients with unicuspid aortic valves treated at our institution, with a focus on 2D and 3D echocardiographic imaging.

Predictors of Aortic Valve Repair Failure

Aortic valve repair is the preferred approach for the treatment of severe aortic insufficiency (AI), as it allows patients to keep their native aortic valve, thus substantially reducing the risk of prosthesis-related complications. Several studies have documented excellent long-term outcomes of aortic valve repair. The major complication of this operation is AI recurrence, with ensuingneed for reoperation. The surgical experience accumulated over the last two decades has allowed for better understanding of the mechanisms of recurrent AI after aortic valve repair. Herein, we review the current state of knowledge on predictors of aortic valve repair failure. These include unaddressed annular dilation, residual cusp prolapse or retraction, commissural orientation, and use of patch material. This enhanced understanding has led to the development of increasingly refined techniques and improved patient outcomes. Continued follow-up and detailed data collection at the time of surgery, together with three-dimensional echo imaging, will allow further improvements in aortic valve repair.

Diagnostic Accuracy of Echocardiography and Intraoperative Surgical Inspection of the Unicuspid Aortic Valve

Unicuspid aortic valve (UAV) is a rare malformation that is often difficult to distinguish from a bicuspid aortic valve (BAV) with commissural fusion by echocardiography or intraoperative surgical inspection. This study assessed the accuracy of intraoperative surgical inspection and two-dimensional echocardiography in diagnosing UAV compared to a gold standard of pathological diagnosis. The Mayo Clinic echocardiographic database, tissue registry database and electronic medical record were searched for all patients assigned a diagnosis of UAV by any technique. Transthoracic (TTE), transesophageal (TEE) echocardiographic, and surgical diagnoses were compared to pathological diagnosis as the standard. A clinical diagnosis of UAV was applied to 380 patients by 1 or more method and in 196 (52%) a pathologic evaluation was available to compare to the clinical description given by TTE, TEE, or surgical inspection. Of these 196 patients, only 58 (30%) had a pathological diagnosis of UAV; the majority were found to be BAVs by pathologic evaluation (n = 132, 67%). For diagnosing UAV, the sensitivity and specificity were 15% and 87% for TTE, 28%, and 82% for TEE, and 52% and 51% for surgical inspection, respectively. Valves with bicuspid morphology and extensive commissural fusion were frequently misclassified as UAV by all methods. In conclusion, intraoperative surgical inspection and echocardiography have limitations for diagnosing UAV due to difficulties in accurately assigning a correct morphological diagnosis, which suggests that the current understanding of the natural history of UAV may be inaccurate.

Unicuspid aortic valve replacement with development of complete heart block: a case report

BACKGROUND

Aortic stenosis is a progressive disease that frequently remains undiagnosed until late in the disease course. In patients that present with symptoms of heart failure and a systolic murmur at a young age, a congenital valvular abnormality must be on the differential. With patients that have accelerated symptoms of aortic stenosis and valvular dysfunction, a unicuspid aortic valve (UAV) could be present. A UAV is often difficult to distinguish from a bicuspid aortic valve (BAV) on transthoracic echocardiography. In patients with congenital valvular abnormalities an ascending aortic aneurysm can also be present. Aortic stenosis changes the jet of fluid emerging from the aortic valve leading to an increased risk for aortic aneurysm dissection and rupture. The gold standard treatment for aortic stenosis secondary to a congenital valvular abnormality is valve replacement. A known risk of aortic valve replacement is conduction abnormalities. In this case, we present a patient with a unicuspid valve who postoperatively develops complete heart block leading to pacemaker implantation.

CASE SUMMARY

We present a case of a 46-year-old Caucasian male with no prior medical history who presented with progressively worsening exertional dyspnoea and palpitations for 7 months. Transthoracic echocardiogram showed a BAV, however, further work up confirmed a unicommissural aortic valve with severe aortic stenosis and moderate regurgitation along with an ascending aortic aneurysm. Aortic valve replacement and aortic aneurysm repair via the Bentall procedure was successfully completed with postoperative course being complicated by a complete heart block and subsequent permanent pacemaker placement.

DISCUSSION

When assessing patients with symptoms of heart failure with a systolic murmur that suggests aortic stenosis at a young age, a UAV must be kept on the differential. The symptoms of aortic stenosis and valvular dysfunction are accelerated in UAVs when compared with BAVs. Currently, the treatment for patients with congenital valvular abnormalities presenting with aortic stenosis is aortic valve replacement using traditional open surgery. A known sequelae of isolated aortic valve replacement is conduction abnormalities that can sometimes lead to permanent pacemaker placement. After the confirmation of unicuspid or bicuspid valve postoperatively, it is important to report any postoperative conduction abnormalities. This is because, currently, there is no literature that compares the incidence of conduction abnormalities after unicuspid replacement to that of other BAV syndromes.

Unicuspid Aortic Valve Presenting with Decompensated Critical Aortic Stenosis

•UAV is a rare congenital anomaly that leads to severe symptomatic stenosis.•Echocardiography plays a critical role in the evaluation of aortic stenosis.•Correctly distinguishing between UAV and BAV is relevant in determining intervention.

Congenital aortic stenosis due to unicuspid unicommissural aortic valve: a case report

BACKGROUND

Unicuspid unicommissural aortic valve is an extremely rare congenital anomaly that usually presents in adulthood but can rarely present in infancy. We report a 17-year-old patient with congenital aortic stenosis secondary to unicuspid unicommissural aortic valve that was successfully treated with aortic valve replacement.

CASE PRESENTATION

The patient was diagnosed with aortic stenosis after a murmur was heard in the newborn nursery and subsequently underwent aortic balloon valvuloplasty 6 weeks after birth. He had been regularly followed up since and underwent numerous cardiac catheterizations, including another aortic balloon valvuloplasty at age 13. During follow-up at age 17, the patient presented with symptomatic severe aortic stenosis and mild left ventricular hypertrophy. Aortic valve replacement was planned since the patient was nearly adult-sized and to reduce the risk of cardiac decompensation. During the operation an unicuspid unicommissural aortic valve was revealed. The patient recovered well post-operatively. He was discharged 5 days after the surgery in good condition and was completely symptom-free at follow-up 6 weeks later.

CONCLUSIONS

Unicuspid aortic valve is a rare congenital anomaly that can cause congenital aortic stenosis. It is seldom diagnosed pre-operatively but should be suspected in infants presenting with aortic stenosis.

Two rare cases of congenital aortic stenosis showing a discrepancy between preoperative imaging diagnosis, intraoperative findings, and histopathological diagnosis

Unicuspid aortic valve (UAV) is an extremely rare congenital heart valve abnormality while bicuspid valve (BAV) has been reported as one of the most common cardiac anomalies. With a UAV usually showing similar presentations to a BAV, such as aortic regurgitation or aortic stenosis (AS), it is challenging to differentiate them from each other in clinical settings. Despite some features shared between both valve disorders, there can be a clinical significance in distinguishing UAV from BAV for the management of patients with these heart anomalies. Herein, we describe two cases where patients with hemodynamically severe AS were diagnosed with BAV and UAV, respectively based on preoperative examinations and intraoperative findings, but subsequent pathological examinations confirmed the opposite diagnosis in both cases. <Learning objective: Preoperative diagnosis of congenital aortic valve diseases can often be challenging. There remains a remarkable number of misleading cases. Thus, it is strongly recommended that an accurate diagnosis should be attempted at the earliest stages of congenital aortic valve disease. Additionally, both careful follow-ups using multiple imaging modalities and confirmations via pathological diagnosis for patients undergoing surgery, if they are first found to be at an advanced stage or remain undiagnosed preoperatively are important.>.

Aortic Valve Repair of a Stenotic Unicuspid Aortic Valve in Young Patients

BACKGROUND

The unicuspid aortic valve (UAV) is a well-described pediatric congenital abnormality, with incidence of 0.02% in the general population. Bicuspidization has been described as a potential surgical option to repair this defect.

METHODS

Seventeen symptomatic young patients with a unicuspid valve combined with either valve insufficiency or valve stenosis underwent aortic valve (AV) bicuspidization procedure by using an equine pericardium. In addition to bicuspidization, 8 patients underwent aortic ring implantation and 5 patients underwent supracoronary replacement of the aorta.

RESULTS

Our results show safety of the bicuspidization procedure. No deaths occurred during our average follow-up period of 26 months. Freedom from reoperation for any valve-related reason was 100% during this follow-up period. We observed a statistically significant increase in the AV area from 0.8 ± 0.1 cm² to 2.8 ± 0.7 cm² (p < 0.01), a statistically significant decrease in the mean systolic pressure gradient from 36 ± 13.3 mm Hg to 9 ± 4 mm Hg (p < 0.001), a statistically significant decrease in aortic insufficiency grade from 2.1 ± 1.0 to 0.6 ± 0.7 (p < 0.01) before and after bicuspidization, respectively, and a statistically significant decrease in the left ventricular end-diastolic diameter from 49.88 ± 5.11 mm to 40.46 ± 7.20 mm (p < 0.0005) and a statistically significant increase of the left ventricular ejection fraction from 56% ± 8.20% to 64% ± 7.83% at the time of follow-up.

CONCLUSIONS

From our study, bicuspidization is an attractive surgical option to repair UAV, particularly in young patients who do not want to be subjected to long-term anticoagulation therapy or who refuse a more traditional surgical approach, such as Ross procedure, for reasons described previously.

Severe Asymptomatic Unicuspid Aortic Stenosis, Myocardial Fibrosis, and Sudden Death: Relevance of Multimodality Imaging

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Myocardial fibrosis can occur in patients with severe asymptomatic aortic stenosis (AS).

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Global longitudinal strain and cardiac magnetic resonance can detect myocardial fibrosis in AS.

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Myocardial fibrosis could help to stratify the arrythmic risk of AS patients.

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This could be useful to determine the timing of referral to surgery.

Severe Aortic Stenosis Associated with Unicommissural Unicuspid Aortic Valve in a Middle Aged Male

Unicuspid aortic valve (UAV) is an extremely rare form of congenital aortic valvular abnormality. Although UAV shows similar clinical characteristics to bicuspid aortic valve, the clinical symptoms develop at earlier age and progress at a faster pace in UAV. In this report, we are presenting a 42-year-old male with severe aortic stenosis associated with unicommissural UAV. The patients underwent a successful Bentall operation.