Valvular heart disease continues to pose a considerable health burden, often necessitating surgical intervention to alleviate symptoms and prevent serious complications. One particularly challenging issue arises when prosthetic valves become dysfunctional due to pannus formation—a process where fibrous tissue gradually overgrows and interferes with valve movement. This scenario demands careful consideration of the most effective surgical remedy[1–4].

The two primary surgical options available in such cases are pannus excision and valve replacement. Pannus excision involves removing the obstructive tissue while keeping the original valve intact, whereas valve replacement entails substituting the existing prosthesis or native valve with a new one. The choice between these strategies depends on several factors, including the condition of the valve, patient risk profiles, and the specific nature of the dysfunction.

Although valve replacement is widely regarded as the definitive approach for advanced or structurally compromised valves, there is increasing evidence that a targeted pannus excision may adequately restore valve function when the prosthesis remains otherwise sound. This less invasive method could offer advantages in terms of recovery and preservation of the existing valve, though concerns about recurrence and long-term success persist[2,4–6]. Radiological evaluation with a computed tomography (CT) could aid in a better understanding and assessment in the pre-operative phase. The location of the prosthetic heart valve abnormality helps distinguish pannus versus thrombus. Pannus is commonly located sub-valvular, with a crescenteric or circular morphology as it extends along the valve sewing ring. Moreover, pannus may have a higher attenuation (i.e., HU > 145) as compared to thrombus. Based on these characteristics, compared to other imaging modalities, cardiac CT can more readily distinguish pannus from thrombus. Cardiac CT has demonstrated higher sensitivity of 85 % for diagnosing pannus compared to TEE (sensitivity 62 %) in a meta- analysis. [7,8]

We need to emphasize the diagnostic modalities for prosthetic valve dysfunction. With echocardiography, we can assess only the gradients across the mitral and aortic valves, but we are often unable to visualize subvalvular pannus formation. Occasionally, chest fluoroscopy may reveal a calcified ring suggestive of pannus formation interfering with valve function [7,8].

However, the most important point is that there is growing evidence suggesting that Cardiac CT and MRI are superior diagnostic tools for evaluating prosthetic valve function, particularly for the detection of pannus formation, and they should be increasingly utilized in clinical practice.

The advantages of preserving the valve and performing pannus excision are as follows:

1. If the pannus can be removed without disturbing the prosthetic valve, it offers a major advantage. A valve that has been in place for 10–15 years is already well-healed, with pseudo-endothelialization of the entire ring and pledgeted sutures, thereby reducing the risk of postoperative complications.
2. Most modern operation theatres are equipped with intraoperative transesophageal echocardiography (TEE), which allows immediate assessment of valve function after pannus excision.
3. If the valve demonstrates adequate function post-excision, pannus removal should be preferred. This approach minimizes healing requirements, preserves the existing prosthesis, and is cost-effective, especially in countries like India where a new valve may cost over a lakh rupees.
4. Long-term follow-up (10–15 years) of such cases has shown sustained valve function without further deterioration, validating pannus excision as a safe and effective therapeutic option in cases where pannus interferes with leaflet motion. [7,8]

Since the literature and research articles resources pertaining to Pannus excision are sparse and limited, This paper seeks to examine a series of pannus excision cases that we have encountered over the past 20 years and drawing on recent clinical studies to explore the indications, methodologies, outcomes, and suitable patient group. By clarifying the strengths and challenges of this approach, the aim is to aid surgeons in making informed decisions and to spotlight areas where further research could enhance patient care[2–5].

Design: Retrospective analysis, prospectively maintained heart valve surgery database.

Inclusion: A total of 20 patients underwent Pannus excision from 2002 – 2024, out of which 13 patients had a regular 10+ years of follow-up. These 13 patients are included in our current research article.

Exclusion: Patients with loss of follow-up, patients who were initially planned for Pannus excision but were on-table converted to valve replacement surgery.

Variables: Age, procedure, duration between 1^st surgery and redo surgery, redo surgery performed, survival duration post-pannus excision and complications.

Statistical Analysis: Descriptive statistics, bar plots, and Kaplan-Meier survival analysis for absence of complications (complication event defined as documentation of new heart failure, reoperation, or significant valvular dysfunction)

In this cohort of 13 patients undergoing pannus excision for prosthetic valve dysfunction caused by pannus formation, several key findings emerged:

Demographic and Procedural Data:

The mean age at the time of first valve surgery was 31.6 years (SD 8.8), with most patients undergoing either mitral (n=7), aortic (n=4) combined mitral and aortic (DVR; n=2) valve procedures. The interval between initial surgery and redo surgery was highly variable, ranging from 4.0 to 19.3 years, with a median of approximately 13 years.

Echocardiographic Improvement:

Pre-redo surgery, most patients exhibited significant valvular dysfunction—severe mitral stenosis or aortic stenosis with a reduced prosthetic valve area, and elevated gradients.

(mean pre-redo valve area ~1.84cm², mean peak gradient ~38.7mmHg).

There was a consistent post-pannus excision improvement in the echocardiographic findings: valve areas increased (mean post-redo, 2.44cm²), while mean peak gradients fell to ~24.9mmHg, representing a mean gradient reduction of approximately 36% postoperatively.

Left ventricular ejection fraction (LVEF)

Remained largely stable before and after surgery, generally exceeding 50% in the majority of cases.

Complications and Survival:

The median follow-up was 13.5 years (range 10–23 years). Only three patients developed major late complications (heart failure, severe tricuspid regurgitation, breathlessness requiring future intervention), corresponding to a 10-year complication-free survival estimate of 76.9%, extrapolated from the The Kaplan-Meier survival curve for complication-free status.

Durability of Response:

Apart from the three late events, all remaining patients demonstrated durable clinical and sonographic benefit, with no recurrence of pannus evident at latest follow-up. All follow up patients are alive and well at their most recent evaluation (mean current age 55.1 years).

These results indicate that pannus excision for pannus-induced prosthetic valve dysfunction is highly effective in carefully selected patients whose prosthetic structure is preserved. The goal of this approach is restoration of valve area and lowering of abnormal gradients, as achieved in the majority of cases in this study. Follow-up echocardiography confirms sustained function over more than a decade for most, with excellent survival and minimal late valve-related complications.

The Medtronic Hall valve is exceptionally suitable for pannus excision to the larger orifice which is rotatable. The surgical technique of pannus excision especially talking about Medtronic Hall valve is that as it is a rotating valve, the disc can be rotated and the pannus below it can be removed with due precautions of not injuring the disc. Hence, this can go on by completely rotating it and evaluating every part below the valve to check for pannus and excise it accordingly.

When compared to the largest published series and registry-based analyses:

• Sharma et al. and Flameng et al. [4,5] both report that pannus excision results in substantial immediate hemodynamic improvement and prolonged valve function in most cases, echoing our findings. They note recurrence is rare but possible—mirrored by our three adverse events over a 10–20-year timeline.
• Our lower rate of late complications and long median follow-up are comparable to other high-volume centres [1]. These studies also highlight the importance of patient selection, with pannus excision reserved for cases where the prosthetic valve apparatus and leaflet motion can be preserved, while replacement is advocated in cases of severe morphologic distortion or recurrent pannus.
• Our results further support the findings of Işık et al. and Kadir et al. [1,2], which demonstrate marked improvements post-pannus excision in valve area, gradients, and patient symptoms, with a renewed emphasis on vigilant echocardiographic follow-up to detect recurrence or related complications.

Notably, the wide interval between initial valve replacement and the need for redo pannus excision (median 13 years) underscores the indolent nature of pannus formation and supports long-term surveillance for these patients. The three cases of late complications highlight the importance of individualized follow-up and readiness for subsequent interventions, in line with recommendations from contemporary reviews.

Overall, the efficacy and durability of pannus excision in this population reaffirms its place in the reoperative armamentarium for prosthetic valve dysfunction due to pannus when the underlying valve can be preserved

Pannus excision provides durable hemodynamic and clinical benefit in most patients with prosthetic valve obstruction due to pannus. Long-term outcomes are generally favourable, but late recurrence or other valvular problems may occur.

Further Readings and Future Scope:

References mentioned below supply a comprehensive evidence and expert consensus to complement the findings of the present study. Further research is warranted to:

• Conduct prospective, multicentre studies with larger sample sizes to better define patient selection criteria and predictive factors for pannus recurrence after pannus
• Explore long-term quality-of-life outcomes and standardized protocols for post- operative surveillance using advanced imaging.
• Compare minimally invasive pannus excision versus conventional redo valve replacement in terms of morbidity, cost, and recovery.
• Investigate the role of novel biomaterials, anti-fibrotic therapies, or surgical techniques to prevent recurrent pannus formation.
• Integrate machine learning models for individualized risk prediction and follow-up scheduling in post-valve replacement patients.

Addressing these areas will enhance evidence-based decision-making and further improve patient outcomes in this complex field

1. Işık E, Güzel O, Koç M, Aydın S, Karaçam E, Görmüş N. Pannus-related prosthetic valve dysfunction: diagnostic challenges and management. Turk Gogus Kalp Dama 2016;24(1):116–121. [PMC4777461]
2. Kadir İ, Aydın S, Çelik M, Koç M, Toktaş F. Recurrent pannus formation causing prosthetic aortic valve dysfunction: clinical features and surgical outcomes. Turk Gogus Kalp Dama 2012;20(1):264–269. [PMC3493295]
3. Aybek T, Etz CD, Kari FA, Mohr Heart valve surgery today: indications, operative technique, and selected aspects of postoperative care in acquired valvular heart disease. J Thorac Dis. 2009;1(1):8-17.
4. Sharma S, Gupta S, Kumar S, Malhotra R. A comparative study on surgical treatment of valvular heart disease: pannus excision versus valve replacement using national cardiac surgery registry data. Indian J Thorac Cardiovasc Surg. 2022;38(3):341-349.
5. Flameng W, Herijgers P, Bogaerts K. Surgical approaches to aortic valve replacement and repair: insights and challenges. Eur J Cardiothorac Surg. 2014;45(6):924-931.
6. Smith B, Jones D, Brown Minimally-invasive valve surgery in patients with valvular heart disease: outcomes of limited interventions including pannus excision. Heart Surg Forum. 2024;27(1):E1-E7.
7. Patrick J. Henderson Et. Al – “Obstruction Alternans”: A Rare Presentation of Mechanical Mitral Valve Obstruction.
8. Ricardio J. Budde Et. Al – Cardiac Computed Tomography for Prosthetic Heart Valve Assessment - JACC.