An in vitro study using confocal laser scanning microscopy to evaluate the marginal misfits of different implant-supported frameworks

PURPOSE

This study aimed to develop and evaluate a simple, non-destructive method for assessing the misfit and passivity of implant-retained prostheses frameworks.

MATERIALS AND METHODS

To simulate the rehabilitation of a mandible posterior partially edentulous area using 3-unit screw-retained frameworks supported by two implants were fabricated and divided into the following five groups (n = 10 in each group): OP = one-piece framework cast in Co-Cr with the conventional method (control-group); Co-Cr frameworks sectioned and welded by laser (=LAS) or tungsten inert gas (=TIG); Co-Cr CAD-CAM = milled Co-Cr framework; Zir CAD-CAM = milled zirconia framework. The horizontal |X| and vertical |Y| misfits were measured using confocal laser scanning microscopy with one or both screws tightened. Data were analyzed by a two-way ANOVA with repeated measures and Bonferroni correction (α = 0.05).

RESULTS

The greatest |X| misfit was observed in the OP group with both screws tightened (290 µm) and one screw tightened (388 and 340 µm). The conventional casting groups sectioned and welded by laser or TIG had lower mean values (235.35 µm, both screws tightened; and 275 µm, one screw tightened) than the OP framework. However, these values still exceeded those of the milled Co-Cr and zirconia frameworks (190 and 216 µm with both screws tightened). Across all reading conditions, every framework subjected to testing consistently maintained vertical |Y| misfit levels below the threshold of 53 µm; however, the milled frameworks exhibited higher vertical misfits than the frameworks obtained by the conventional cast method.

CONCLUSIONS

The frameworks, whether cast and sectioned with laser welding or milled from Co-Cr, exhibit improved marginal misfit and enhanced passive fit when compared to other fabrication methods. Additionally, the use of confocal laser scanning microscopy is highly effective for passivity and misfit analysis.

Using human-in-the-loop optimization for guiding manual prosthesis adjustments: a proof-of-concept study

Introduction: Human-in-the-loop optimization algorithms have proven useful in optimizing complex interactive problems, such as the interaction between humans and robotic exoskeletons. Specifically, this methodology has been proven valid for reducing metabolic cost while wearing robotic exoskeletons. However, many prostheses and orthoses still consist of passive elements that require manual adjustments of settings. Methods: In the present study, we investigated if human-in-the-loop algorithms could guide faster manual adjustments in a procedure similar to fitting a prosthesis. Eight healthy participants wore a prosthesis simulator and walked on a treadmill at 0.8 ms-1 under 16 combinations of shoe heel height and pylon height. A human-in-the-loop optimization algorithm was used to find an optimal combination for reducing the loading rate on the limb contralateral to the prosthesis simulator. To evaluate the performance of the optimization algorithm, we used a convergence criterium. We evaluated the accuracy by comparing it against the optimum from a full sweep of all combinations. Results: In five out of the eight participants, the human-in-the-loop optimization reduced the time taken to find an optimal combination; however, in three participants, the human-in-the-loop optimization either converged by the last iteration or did not converge. Discussion: Findings from this study show that the human-in-the-loop methodology could be helpful in tasks that require manually adjusting an assistive device, such as optimizing an unpowered prosthesis. However, further research is needed to achieve robust performance and evaluate applicability in persons with amputation wearing an actual prosthesis.

Improving shared decision-making for prosthetic care: A qualitative needs assessment of prosthetists and new lower-limb prosthesis users

BACKGROUND

Prosthesis design is complex and multiple appropriate options exist for any individual with lower-limb amputation. However, there is insufficient evidence for guiding decision-making. Shared decision-making (SDM) offers an opportunity to incorporate patient-specific values and preferences where evidence is lacking for prosthesis design decisions. To develop resources to facilitate SDM, and consistent with the International Patient Decision Aid Standards, it is necessary to identify the decisional needs of prosthetists and prosthesis users for prosthesis design decisions.

OBJECTIVES

To assess the needs of prosthetists and new prosthesis users for SDM about the first prosthesis design.

STUDY DESIGN

Qualitative descriptive design.

METHODS

Six focus groups were conducted with 38 prosthetists. Individual semistructured interviews were conducted with 17 new prosthesis users. Transcripts were analyzed using directed content analysis, with codes defined a priori using existing frameworks for SDM: the Three Talk Model for SDM and the Ottawa Decision Support Framework.

RESULTS

Four main themes were identified among prosthetists and prosthesis users: acknowledging complexity in communication, clarifying values, recognizing the role of experience to inform preferences , and understanding the prosthetic journey .

CONCLUSIONS

Resources that support SDM for the first prosthesis design should consider methods for identifying individual communication needs, support with clarifying values, and resources such as experience for achieving informed preferences, within the context of the overall course of rehabilitation and recovery following lower-limb amputation. The themes identified in this work can inform SDM to promote collaborative discussion between prosthetists and new prosthesis users when making prosthesis design decisions.

Preservation of Residual Limb Length with Antibiotic-loaded Bone Cement Implantation to Treat Femoral Periprosthetic Infection: A Case Report

Background

: Fitting a femoral prosthesis in a transfemoral amputee with a very short amputation stump is challenging. This case report aimed to introduce an effective and simple method that can preserve the residual limb length by the implantation of antibiotic-loaded bone cement for the treatment of a patient with femoral periprosthetic infection.

Case

: A 30-year-old man who had osteosarcoma at the age of 13 years underwent transfemoral amputation 17 years after the initial surgery because of periprosthetic infection. Antibiotic-loaded bone cement was inserted into the infected bone marrow to control the residual infection and to preserve the stump length. The infection resolved, and the patient regained functional gait using a femoral prosthesis.

Discussion

: This case report demonstrates the usefulness of antibiotic-loaded cement in preserving the length of residual limbs and for femoral prosthesis fitting after periprosthetic infection. Maintaining the residual bone length is crucial in amputees for the functional fitting of femoral prostheses. The use of antibiotic-loaded bone cement has potential as a simple and useful surgical option in amputees after periprosthetic infection.

Fitting transtibial and transfemoral prostheses in persons with a severe flexion contracture: problems and solutions - a systematic review

PURPOSE

In persons with a hip or knee flexion contracture ≥25°, fitting a prosthesis is said to be difficult. This systematic review aims to assess the evidence for fitting of a prosthesis in persons with a severe contracture (≥25°) after a lower limb amputation.

METHOD

PubMed, Embase, Scopus, CINAHL, and Orthotics & Prosthetics Virtual Library databases were searched from inception to December 2019, using database specific search terms related to amputation, prosthesis, and contracture. Reference lists of included studies were checked for relevant studies. Quality of the included studies was assessed using the critical appraisal checklist for case reports (Joanna Briggs Institute).

RESULTS

In total, 13 case studies provided evidence for fitting of a prosthesis in more than 63 persons with a transtibial amputation and three with a transfemoral amputation, all of whom had a hip or knee flexion contracture ≥25°. Some studies found a reduction in contractures after prosthesis use.

CONCLUSIONS

Several techniques for fitting a prosthesis in case of a flexion contracture ≥25° were found. Contracture reduction occurred in some cases and was possibly related to prosthesis use. Fitting a transtibial or transfemoral prosthesis in persons with a lower limb amputation with a severe flexion contracture is possible.IMPLICATIONS FOR REHABILITATIONThis study provides information on prosthesis prescriptions and adaptations for persons with a transfemoral and transtibial amputation with a flexion contracture ≥25°.The fitting of bent prostheses is not limited by prosthetic components and techniques.Parallel to the use of bent prostheses, it is also important to treat the contracture.

Lower limb prosthetic interfaces: Clinical and technological advancement and potential future direction

The human-prosthesis interface is one of the most complicated challenges facing the field of prosthetics, despite substantive investments in research and development by researchers and clinicians around the world. The journal of the International Society for Prosthetics and Orthotics, Prosthetics and Orthotics International, has contributed substantively to the growing body of knowledge on this topic. In celebrating the 50th anniversary of the International Society for Prosthetics and Orthotics, this narrative review aims to explore how human-prosthesis interfaces have changed over the last five decades; how research has contributed to an understanding of interface mechanics; how clinical practice has been informed as a result; and what might be potential future directions. Studies reporting on comparison, design, manufacturing and evaluation of lower limb prosthetic sockets, and osseointegration were considered. This review demonstrates that, over the last 50 years, clinical research has improved our understanding of socket designs and their effects; however, high-quality research is still needed. In particular, there have been advances in the development of volume and thermal control mechanisms with a few designs having the potential for clinical application. Similarly, advances in sensing technology, soft tissue quantification techniques, computing technology, and additive manufacturing are moving towards enabling automated, data-driven manufacturing of sockets. In people who are unable to use a prosthetic socket, osseointegration provides a functional solution not available 50 years ago. Furthermore, osseointegration has the potential to facilitate neuromuscular integration. Despite these advances, further improvement in mechanical features of implants, and infection control and prevention are needed.

Optimizing P2 Neochordal Length and Stability in Mitral Valve Repair With Use of a Polypropylene Loop

Determining the optimal length of artificial chordae tendineae and then effectively securing them is a major challenge in mitral valve repair. Our technique for measuring and stabilizing neochordae involves tying a polypropylene suture loop onto the annuloplasty ring. We used this method in 4 patients who had moderate-to-severe mitral regurgitation from degenerative posterior leaflet (P2) prolapse and flail chordae. Results of intraoperative saline tests and postoperative transesophageal echocardiography revealed only mild insufficiency. One month postoperatively, echocardiograms showed trivial regurgitation in all 4 patients. We think that this simple, precise method for adjusting and stabilizing artificial chordae will be advantageous in mitral valve repair.

Fit of cobalt-chromium copings fabricated by the selective laser melting technology and casting method: A comparative evaluation using a profilometer

BACKGROUND

This study aimed to assess the marginal adaptation and internal fit of cobalt-chromium copings fabricated by the selective laser melting (SLM) and conventional techniques using a profilometer.

MATERIALS AND METHODS

In this in vitro study sample size was calculated to be a total of 10 in two groups (n = 5). A brass model was used that had a circular cross-section with a round shoulder margin with 0.5 mm thickness and axial walls with 10 mm length and 6° taper. The copings fabricated with both techniques (SLM and casting method) were placed on the model, and vertical marginal gap was measured using a profilometer. The internal fit of copings was assessed by weighing the light-body addition silicone applied inside them, which simulated the cement. Data were analyzed through parametric (Independent t-test) and nonparametric (Mann-Whitney U-test, Bootstrap, Spearman, and Pearson Correlation) analysis. All analyses were performed at a significant level (α = 0.05) using SPSS.

RESULTS

The mean marginal gap in the casting group (132.93 ± ) was significantly higher than that in the SLM group (67.14 ± 15.67 μm) (P < 0.05). The mean weight of light-body silicone was 9.60 ± in the SLM and 8.70 ± 1.21 mg in the casting group. No significant difference was noted between the two groups regarding the internal fit (P > 0.05).

CONCLUSION

The copings fabricated by the SLM technique showed a smaller vertical marginal gap compared to the casting group. However, the two groups were not significantly different in terms of internal fit.

Bionic Upper Limb Reconstruction: A Valuable Alternative in Global Brachial Plexus Avulsion Injuries-A Case Series

Global brachial plexopathies including multiple nerve root avulsions may result in complete upper limb paralysis despite surgical treatment. Bionic reconstruction, which includes the elective amputation of the functionless hand and its replacement with a mechatronic device, has been described for the transradial level. Here, we present for the first time that patients with global brachial plexus avulsion injuries and lack of biological shoulder and elbow function benefit from above-elbow amputation and prosthetic rehabilitation. Between 2012 and 2017, forty-five patients with global brachial plexus injuries approached our centre, of which nineteen (42.2%) were treated with bionic reconstruction. While fourteen patients were amputated at the transradial level, the entire upper limb was replaced with a prosthetic arm in a total of five patients. Global upper extremity function before and after bionic arm substitution was assessed using two objective hand function tests, the action research arm test (ARAT), and the Southampton hand assessment procedure (SHAP). Other outcome measures included the DASH questionnaire, VAS to assess deafferentation pain and the SF-36 health survey to evaluate changes in quality of life. Using a hybrid prosthetic arm mean ARAT scores improved from 0.6 ± 1.3 to 11.0 ± 6.7 (p = 0.042) and mean SHAP scores increased from 4.0 ± 3.7 to 13.8 ± 9.2 (p = 0.058). After prosthetic arm replacement mean DASH scores improved from 52.5 ± 9.4 to 31.2 ± 9.8 (p = 0.003). Deafferentation pain decreased from mean VAS 8.5 ± 1.0 to 6.7 ± 2.1 (p = 0.055), while the physical and mental component summary scale as part of the SF-36 health survey improved from 32.9 ± 6.4 to 40.4 ± 9.4 (p = 0.058) and 43.6 ± 8.9 to 57.3 ± 5.5 (p = 0.021), respectively. Bionic reconstruction can restore simple but robust arm and hand function in longstanding brachial plexus patients with lack of treatment alternatives.

Reported physical activity and quality of life in people with lower limb amputation using two types of prosthetic suspension systems

BACKGROUND

Vacuum-assisted suspension systems provide better suspension than non-vacuum systems, but data are limited on whether they improve physical activity levels and quality of life for people with amputation.

OBJECTIVES

To compare the physical activity and quality of life levels of people with transtibial amputation using PIN/LOCK suspension system or vacuum-assisted suspension systems with those of able-bodied controls and to investigate parameters associated with physical activity levels.

STUDY DESIGN

A cross-sectional observational study.

METHODS

Fifty-one people with amputation and 51 controls participated. The International Physical Activity Questionnaire Short Form and Short Form 36 were used to measure the physical activity and quality of life, respectively.

RESULTS

The total physical activity and Short Form 36 scores were significantly lower in the participants with amputation than the controls. There were no significant differences between the two types of suspension systems in terms of physical activity levels and quality of life. The vacuum-assisted suspension system users reported significantly more bodily pain on the Short Form 36 questionnaire than the controls (p = 0.003). The only parameter that correlated significantly with the total physical activity was the Short Form 36 physical functioning subscale (r = 0.302, p = 0.031).

CONCLUSION

Contrary to our expectations, vacuum-assisted suspension system users compared to PIN/LOCK users did not report greater levels of physical activity or improved quality of life or levels closer to comparable controls.

CLINICAL RELEVANCE

A better understanding of the effects of different prosthetic suspension systems on physical activity and quality of life may help clinicians when prescribing prostheses, as well as setting appropriate prosthetic expectations. This study suggests that vacuum-assisted suspension systems and PIN/LOCK suspension systems provide equal benefit to users with regards to physical activity and quality of life.

Incidence and predictors of mismatch after mechanical mitral valve replacement

Background

Patient-prosthesis mismatch after mitral valve replacement has an unfavorable postoperative hemodynamic outcome, which underlines the importance of identifying and preventing prosthesis- and patient-related risk factors. This study was conducted to determine the incidence and identify possible predictors of patient-prosthesis mismatch.

Methods

A prospective study was conducted on 715 patients with a mean age of 42 ± 11 years who underwent mechanical mitral valve replacement between 2013 and 2017. The effective orifice area of the prostheses was estimated by the continuity equation, and a mismatch was defined as an effective orifice area index ≤1.2 cm2·m−2. The mean clinical and echocardiographic follow-up was 26.74 ± 11.58 months. Multivariate regression analysis was performed to identify predictors of patient-prosthesis mismatch.

Results

Patient-prosthesis mismatch was detected in 382 (53.4%) patients. A small mechanical prosthesis (<27 mm) was inserted in 54.3%. Mortality during follow-up was 9% (65 patients). Patient-prosthesis mismatch was identified in patients with preoperative rheumatic mitral valve pathology, associated tricuspid regurgitation, higher New York Heart Association class, preoperative atrial fibrillation, mitral stenosis, and small preoperative left ventricular dimensions. Multivariate analysis identified mitral stenosis, preoperative atrial fibrillation, and small postoperative left ventricular end-diastolic dimension as risk factors for patient-prosthesis mismatch.

Conclusion

Patient-prosthesis mismatch is a common sequela after mechanical mitral valve replacement. Identification of predictors of patient-prosthesis mismatch can help so that a preoperative strategy can be implemented to avoid its occurrence.

Prosthesis satisfaction in lower limb amputees: A systematic review of associated factors and questionnaires

BACKGROUND

Factors influencing patient satisfaction with a transtibial prosthesis have been studied fragmentarily. The aims of this systematic review were to review the literature regarding factors of influence on patient satisfaction with a transtibial prosthesis, to report satisfaction scores, to present an overview of questionnaires used to assess satisfaction and examine how these questionnaires operationalize satisfaction.

METHODS

A literature search was performed in PubMed, Embase, PsycInfo, CINAHL, Cochrane, and Web of Knowledge databases up to February 2018 to identify relevant studies.

RESULTS

Twelve of 1832 studies met the inclusion criteria. Sample sizes ranged from 14 to 581 participants, mean age ranged from 18 to 70 years, and time since amputation ranged from 3 to 39 years. Seven questionnaires assessed different aspects of satisfaction. Patient satisfaction was influenced by appearance, properties, fit, and use of the prosthesis, as well as aspects of the residual limb. These influencing factors were not relevant for all amputee patients and were related to gender, etiology, liner use, and level of amputation. No single factor was found to significantly influence satisfaction or dissatisfaction. Significant associations were found between satisfaction and gender, etiology, liner use, and level of amputation.

CONCLUSION

Relevance of certain factors for satisfaction was related to specific amputee patient groups. Questionnaires assessing satisfaction use different operationalizations, making comparisons between studies difficult.

Case study: Correction of angular deformity post-trans-tibial amputation to improve prosthesis fit and comfort

BACKGROUND

This case report describes the revision of a trans-tibial amputation complicated by a proximal malunited fracture. It demonstrates the complexity of decisions involved in revisions of this nature.

CASE DESCRIPTION AND METHODS

The patient presented has a painful stump due to breakdown of soft tissues. She had been suffering for over a year with pressure sores and inability to use a prosthesis resulting from this, decreasing her quality of life. Malunion of a tibial fracture proximal to the amputation complicated her condition.

FINDINGS AND OUTCOMES

Initially it was feared that the amputation level would be converted to a through-knee amputation, but wedge osteotomy of the tibia allowed coverage of the stump, increasing functionality for the patient, while still maintaining a below-knee stump.

CONCLUSION

This report highlights the importance of addressing the cause of soft tissue problems in an amputation revision, which must be addressed on a case-by-case basis.

CLINICAL RELEVANCE

This case offers an insight into the decision-making process in limb reconstruction and suggests a solution for similar cases. It is important that all surgical options are considered before amputation length is sacrificed.

Use of the satisfaction with amplification in daily life questionnaire to assess patient satisfaction following remote hearing aid adjustments (telefitting)

Background

Hearing loss can affect approximately 15% of the pediatric population and up to 40% of the adult population. The gold standard of treatment for hearing loss is amplification of hearing thresholds by means of a hearing aid instrument. A hearing aid is an electronic device equipped with a topology of only three major components of aggregate cost. The gold standard of hearing aid fittings is face-to-face appointments in hearing aid centers, clinics, or hospitals. Telefitting encompasses the programming and adjustments of hearing aid settings remotely. Fitting hearing aids remotely is a relatively simple procedure, using minimal computer hardware and Internet access.

Objective

This project aimed to examine the feasibility and outcomes of remote hearing aid adjustments (telefitting) by assessing patient satisfaction via the Portuguese version of the Satisfaction With Amplification in Daily Life (SADL) questionnaire.

Methods

The Brazilian Portuguese version of the SADL was used in this experimental research design. Participants were randomly selected through the Rehabilitation Clinical (Espaco Reouvir) of the Otorhinolaryngology Department Medical School University of Sao Paulo. Of the 8 participants in the study, 5 were female and 3 were male, with a mean age of 71.5 years. The design consisted of two face-to-face sessions performed within 15 working days of each other. The remote assistance took place 15 days later.

Results

The average scores from this study are above the mean scores from the original SADL normative data. These indicate a high level of satisfaction in participants who were fitted remotely.

Conclusions

The use of an evaluation questionnaire is a simple yet effective method to objectively assess the success of a remote fitting. Questionnaire outcomes can help hearing stakeholders improve the National Policy on Hearing Health Care in Brazil. The results of this project indicated that patient satisfaction levels of those fitted remotely were comparable to those fitted in the conventional manner, that is, face-to-face.

Radiographic diagnosis of dental restoration misfit: a systematic review

The objective of this study was to perform a systematic review on the use of radiographic methods for the diagnosis of misfit in dental prostheses and restorations. The MEDLINE bibliographic database was searched from 1950 to February 2014 for reports on the radiographic diagnosis of misfits. The search strategy was limited to English-language publications using the following combined MeSH terms in the search strategy: (Dental Restoration OR Dental Prosthesis OR Crown OR Inlays OR Dental Abutments) and (Dental Leakage OR Prosthesis Fitting OR Dental Marginal Adaptation OR Surface Properties) and (Radiography, Dental OR Radiography, Dental, Digital OR Cone-Beam Computed Tomography). Twenty-eight publications were identified and read in full text, and 14 studies fulfilled criteria for inclusion. Information regarding the use of radiographic methods for the diagnosis of misfits in dental prosthesis and restorations, and in which the methodology/results comprised information regarding how the sample was collected/prepared, the method, imaging protocol, presence of a reference test and the outcomes were evaluated. QUADAS criteria was used to rate the studies in high, moderate or low quality. The evidence supporting the use of radiographic methods for the diagnosis of misfits in dental prosthesis and restorations is limited to low-/moderate-quality studies. The well-established intra-oral orthogonal projection is still under investigation and considered the most appropriate method, both when evaluating the relation between dental restoration to tooth and abutment to implant. Studies using digital radiographs have not evaluated the effect of image post-processing, and tomography has not been evaluated.

Strategy to avoid patient-prosthesis mismatch: aortic root enlargement

BACKGROUND

The choice of a valve with an effective orifice area matching the body surface area and providing efficient hemodynamics is an important factor affecting mortality and morbidity in patients undergoing aortic valve replacement.

PATIENTS AND METHODS

Our preventative strategy was to implant a larger prosthetic valve by aortic root enlargement using the Nunez procedure in 17 patients between February 2010 and January 2011. The decision to enlarge the aortic root was taken when the 19-mm sizer could not be negotiated easily through the aortic root, or on the basis of body surface area of the patient or type of prosthesis available.

RESULTS

Postoperative reductions in peak and mean pressure gradients across aortic valve of 12.8-16.5 and 10.2-12.6 mm Hg, respectively, were observed. Postoperative effective orifice areas of the aortic valves were 1.1-1.5 cm(2). By upsizing the aortic valve, we were able to eliminate patient-prosthesis mismatch in 5 patients, and reduce severe patient-prosthesis mismatch to moderate in 11.

CONCLUSION

Aortic root enlargement is a safe procedure. Therefore, cardiac surgeons should not be reluctant to enlarge the aortic root with an autologous pericardial patch to permit implantation of an adequate size of aortic valve prosthesis, with minimal additional aortic crossclamp time and no added cost.

Adaptation to prostheses among patients with major lower-limb amputations and its association with sociodemographic and clinical data

CONTEXT AND OBJECTIVE

Lower-limb amputation compromises patients' independence and autonomy, and therefore they should be referred for rehabilitation in order to adapt to prostheses and regain autonomy. The aim here was to assess adaptation to prostheses among patients with major lower-limb amputations and its association with sociodemographic and clinical data.

DESIGN AND SETTING

This was a cross-sectional study in the city of Aracaju, Brazil.

METHODS

The patients were identified by primary healthcare teams. The inclusion criterion was that these should be patients who underwent major lower-limb amputations of any etiology. Associations between sociodemographic and clinical variables and the adaptation to lower-limb prostheses were assessed.

RESULTS

149 patients were examined. Adaptation to the prosthesis occurred in 40% (60/149) of them, but only 62% (37/60) were using it. Adaptation occurred more often among male patients (P = 0.017) and among those who had a higher educational level (P = 0.013), with a longer time since amputation (P = 0.049) and when the etiology was trauma (P = 0.003). The result from logistic regression analysis showed that only patients with low education (P = 0.031) were significantly associated with a lower frequency of adaptation to prostheses.

CONCLUSION

It was found that patients with a low educational level became adapted to the prosthesis less frequently.

Right ventricle-sparing left ventricular resection and replacement with a continuous-flow rotary blood pump: an in vivo experiment

Despite recent advances in left ventricular assist device and total artificial heart technologies, these devices are still so large that they pose a significant problem in small patients with refractory heart failure. Excising the left ventricle while preserving the right ventricle--and then replacing the left ventricle with a mechanical pump--has been proposed as an alternative approach to this problem. We conducted a pilot study to evaluate possible surgical techniques and the hemodynamic effects of right ventricle-sparing left ventricular resection and replacement with a continuous-flow rotary blood pump in a healthy bovine model.

A modification to the Manouguian aortoplasty for biological valve implantation in patients with small (< or =19 mm) aortic anuli--rationale and benefit

Enlargement of a small aortic root using the Manouguian technique for biological valve implantation can be challenging when rigid, severely calcified noncoronary parts of the aortic anulus are encountered in combination with outsized heights of interleaflet triangles. To maximize the efficacy of the Manouguian technique, we applied a modification--the rationale, technical details, and benefits of which we describe herein.