Qualification: 
MBBS, DNB
rijumenon@aims.amrita.edu

Dr. Riju R. Menon currently serves as Professor at the Department of General Surgery, School of Medicine, Kochi.

Publications

Publication Type: Journal Article

Year of Publication Title

2019

N. Raveendran, Mohandas, A., Riju R. Menon, Menon, A. Somasekhar, Biswas, R., and Dr. Jayakumar Rangasamy, “Ciprofloxacin and Fluconazole Containing Fibrin Nanoparticles Incorporated Chitosan Bandages for the Treatment of Polymicrobial Wound Infections”, ACS Applied Bio Materials, vol. 2, no. 1, pp. 243-254, 2019.[Abstract]


Polymicrobial wound infections often requires high dosage of antibiotics and fungicides. However, prolonged antimicrobial therapies are associated with potential systemic side effects and increased risk for the development of drug resistant microbes. With this focus, we aimed at developing chitosan bandages loaded with anti-microbial (ciprofloxacin and fluconazole) drug loaded nanoparticles for a sustained slow release of drugs. The particle sizes of the prepared ciprofloxacin and flucanazole loaded fibrin nanoparticles were observed to be 132 ± 16 and 175 ± 17 nm respectively. The chitosan bandages with drug containing nanoparticles were flexible with adequate tensile strength and porosity of 80-85%, which would favour excess exudates absorption in an infectious wound. The in vitro toxicity of the bandages studied against human dermal fibroblast (HDF) cell line proved its cytocompatibility. Ciprofloxacin and fluconazole from bandages released upto 14 days in a sustained manner. The antimicrobial drugs loaded bandages showed significant antimicrobial activity towards polymicrobial cultures of C. albicans, E. coli & S. aureus in vitro and ex vivo. In vivo studies were conducted on polymicrobial infected rat wound model. A significant reduction in microbial load was obtained upon application of antimicrobial drug loaded chitosan bandages in vivo.

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2018

Riju R. Menon, C Nair, G., Misha J. C. Babu, and Pradeep Jacob, “Factors influencing adverse outcomes in non diabetic necrotizing fascitis- a retrospective study”, Medical Journal Medica Innovatica, vol. 7, no. 1, pp. 16-20, 2018.[Abstract]


Background: Necrotising fasciitis is a rare severe soft tissue infection with a paucity of early symptoms to diagnose the condition. Early diagnosis and institution of treatment may improve outcome.

Aim: To study the factors likely to influence rate of mortality.

Methods: We present a retrospective analysis of a cohort of 42 patients of non-diabetic necrotising fasciitis over 10 years. After clinical examination and workup patient underwent early debridement with empirical antibiotic therapy. The features used for analysis included age, gender, concurrent systemic diseases (diabetes mellitus, coronary artery disease, chronic liver disease, chronic kidney disease and cancer), duration between the onset of symptom and wound debridement and laboratory parameters

Results: Analysis showed that the duration between onset of first symptom and debridement was the key factor deciding the outcome. Mortality is not affected by the microbiological spectrum.

Conclusion: Early adequate source control with debridement gives the best results. Morbidity, mortality and renal risk increase with delay in treatment. Early empirical antibiotic therapy only helps in masking the symptoms.

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2018

Riju R. Menon, Nair, G. C., Misha J. C. Babu, and Pradeep Jacob, “Acute pancreatitis and primary hyperparathyroidism: Effect of parathyroidectomy”, Formosan Journal of Surgery, vol. 51, no. 6, pp. 219-222, 2018.[Abstract]


Background: The association between primary hyperparathyroidism (PHPT) and acute pancreatitis (AP) is well known. However, the causal association is disputed.

Aims: The present cohort study of PHPT patients was done: (1) to assess the prevalence of AP and (2) to assess the effect of successful parathyroidectomy in preventing further recurrence.

Materials and Methods: Case records of patients admitted with AP during the study period were reviewed. Diagnosis of PHPT among this group was based on serum level of corrected calcium and parathyroid hormone. Review of records of patients who were successfully operated for PHPT was done. Records of patients treated with confirmed diagnosis of AP during the study period were reviewed. Variables used for analysis were serum levels of calcium (adjusted to serum albumin), phosphate, intact parathyroid hormone, 25-OH-Vitamin D, alkaline phosphatase, and estimated glomerular filtration rate (eGFR). For continuous/numerical variables with two groups, Mann–Whitney U-test was applied. Multivariate regression analysis was done if the univariate analysis showed significance (P < 0.05).

Results: There were 13 (7.5%) patients with confirmed diagnosis of AP and serum calcium level significantly elevated in this group. There was a linear association of serum calcium with AP. Successful parathyroidectomy prevented further episodes in 11 (84.6%) of patients. There was 2% prevalence of PHPT among 558 patients with AP.

Conclusions: Hypercalcemia in PHPT patients was significantly associated with AP and early parathyroidectomy prevented further recurrence.

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2018

Riju R. Menon, Gopalakrishnan, N., Babu, M., Pradeep Jacob, and G Krishna, P., “The Outcome of Papillary Thyroid Cancer Associated with Graves’ Disease: A Case Control Study”, Journal of Thyroid Research, vol. 2018, p. 5, 2018.[Abstract]


INTRODUCTION:
Thyroidectomy is now a less popular therapeutic option for Graves' disease. The frequency of thyroid nodule and the cancer risk of these nodules accompanying Graves' disease are controversial. The outcome of thyroid cancers coexisting with Graves' disease is debated.

STUDY DESIGN:
Designed as retrospective case control study of papillary thyroid cancers associated with Graves' disease and those with euthyroid background. Pathological characteristics and outcome of papillary thyroid cancers in the two groups were compared.

RESULTS:
The tumour characteristics did not differ significantly in the groups. The patients were followed for a mean period of 77.32 months and found significant incidences of disease progression in patients with papillary thyroid cancer associated with Graves' disease (p = 0.034; OR 2.747, CI 1.078-7.004). Disease progression as new distant metastases mostly in skeletal locations was high in this group compared to euthyroid group (p = 0.027; OR 4.121, CI 1.008-15.600). There was higher incidence of cumulative metastatic diseases in papillary thyroid cancer associated with Graves' disease.

CONCLUSION:
Papillary thyroid cancers associated with Graves' disease show aggressive biological behaviour and favoured site of distant metastases was osseous locations. Early diagnosis by routine screening of Graves' disease patients with ultrasound imaging and aspiration studies is recommended.

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2017

Riju R. Menon, Murali, S., C. Nair, G., Misha J. C. Babu, and Pradeep Jacob, “Correlation between the cernea classification of external branch of superior laryngeal nerve in relation to the ultrasound-based volume of thyroid gland”, Indian Journal of Endocrinology and Metabolism, vol. 21, no. 6, pp. 845-847, 2017.[Abstract]


Introductíon:
Goiter is a very common problem dealt with by surgeons. Surgical treatment of thyroid requires removal of a part (hemi) or whole of the gland (total thyroidectomy). The external branch of the superior laryngeal nerve (EBSLN) is an important but less researched structure to be preserved during surgery. Various studies have described the incidence of different types of EBSLN, but have not described regarding the relationship between the change in volume of the gland to the nerve

Materials and Methods:
A prospective analysis of 100 patients who underwent total thyroidectomy in our department was done. All patients underwent preoperative ultrasonography and the volume of the gland was calculated. Intraoperatively, the EBSLN was identified and preserved prior to ligating the superior thyroid vessels. The nerve was classified as per the Cernea classification. The gland was divided into high and low volume, taking 20 ml as the cutoff. The incidence of Type 2 nerve in a low-volume gland was compared with that of a high-volume gland.

Results:
In 100 patients (200 nerves), 191 nerves were identified. The nerve was type 1 in 56/200 (28%), Type 2a in 116/200 (58%), and Type 2b in 19/200 (9%) patients. In large-volume glands, Type 2 nerve was more common (87%).

Conclusion:
Dissection of thyroid gland requires expertise to preserve the EBSLN. Large volume glands pose a more difficult challenge, as the gland is more closer to the nerve.

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2017

Dr. Lalitha Biswas, CG, N., M, B., Pradeep Jacob, Riju R. Menon, AK, R., and K, N., “Lack of Association of B-type Raf Kinase V600E Mutation with High-risk Tumor Features and Adverse Outcome in Conventional and Follicular Variants of Papillary Thyroid Carcinoma”, Indian Journal of Endocrinol Metab, vol. 21, no. 2, pp. 329-333, 2017.[Abstract]


INTRODUCTION:
Somatic B-type Raf kinase (BRAF) V600E mutation in exon 15 was frequently found in high frequencies associated with papillary thyroid cancer (PTC). The phenotype of these cancers expressed aggressive clinical and pathological features. The present study aimed to assess the prevalence of BRAF V600E mutation among conventional and follicular variants of PTC and its association with aggressive tumor factors and outcome.

STUDY DESIGN:
Patients who were operated and received further treatment for PTC during 2012 were included in the study. BRAF V600E mutation analysis was done by extracting genomic DNA from tumor tissue.

RESULTS:
Of the 59 patients included in the study, 51% harbored BRAF V600E mutation, but the mutation status was not associated with aggressive tumor factors and adverse outcome.

CONCLUSION:
BRAF V600E mutation was not significant predictor of aggressive tumor behavior in conventional and follicular variants of PTC.

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2017

Riju R. Menon, R, R., and Misha J. C. Babu, “Study of Accuracy of Clinical Examination in Comparison with MR Fistulogram in Fistula in Ano”, Amrita Journal of Medicine, 2017.

2017

A. Jayasree, Mohandas, A., Seethalakshmy, S., Suresh, M., Riju R. Menon, Biswas, R., and Jayakumar, R., “Bi-layered nanocomposite bandages for controlling microbial infections and overproduction of matrix metalloproteinase activity”, International Journal of Biological Macromolecules, vol. 110, 2017.[Abstract]


Chronic diabetic wounds is characterised by increased microbial contamination and overproduction of matrix metalloproteases that would degrade the extracellular matrix. A bi-layer bandage was developed, that promotes the inhibition of microbial infections and matrix metalloprotease (MMPs) activity. Bi-layer bandage containing benzalkonium chloride loaded gelatin nanoparticles (BZK GNPs) in chitosan-Hyaluronic acid (HA) as a bottom layer and sodium alendronate containing chitosan as top layer was developed. We hypothesized that the chitosan-gelatin top layer with sodium alendronate could inhibit the MMPs activity, whereas the chitosan-HA bottom layer with BZK GNPs (240 ± 66 nm) would enable the elimination of microbes. The porosity, swelling and degradation nature of the prepared Bi-layered bandage was studied. The bottom layer could degrade within 4 days whereas the top layer remained upto 7 days. The antimicrobial activity of the BZK NPs loaded bandage was determined using normal and clinical strains. Gelatin zymography shows that the proteolytic activity of MMP was inhibited by the bandage.

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2016

Riju R. Menon, “Sapheno-Femoral Junction Anatomy and Haemodynamics in Indian Patients”, Amrita Journal of Medicine, vol. 12, no. 2, pp. 1 - 44, 2016.[Abstract]


Varicose veins, a common disease in surgical practice, has vexed surgeons for ages, due to its various problems. We hereby present a pilot study of 80 consecutive patients who underwent anatomical and haemodynamic evaluation at the time of Tren-delenberg procedure. Aim 1.To study the location of the saphenofemoral junction(SFJ) in relation to the pubic tubercle. 2.To locate variations in the pattern of tributaries around the SFJ 3.To analyse the haemodynamics of the SFJ Materials and methods 80 consecutive patients who underwent Trendelenberg procedure from August 2007 to August 2008 are presented. Radiological and clinical evaluation were done and patients were subjected to Trendelenberg procedure at which time position of the Sapheno-Femoral junction(SFJ) in relation to pubic tubercle was measured, also noting nature and number of tributaries. A demonstration of the severity of reflux was made and all the information was noted and computed. Results We found that in the Indian patient the position of the SFJ was higher and more medial than the Western counterpart. There were fewer tributaries in the Indian patient. The external pudendal artery was seen more commonly in the Indian patient and could act as a landmark for identification of the SFJ. Conclusion SFJ was seen at a much higher point contrary to the popular anatomy. High incision using the pubic tubercle as the reference point gives good exposure for flush ligation and identification of the tributaries at the SFJ thereby preventing inadequate primary surgery. In our study, there are between 4-5 tributaries at the SFJ and these need to be completely identified and disconnected. Deep external pudendal artery is seen as it goes laterally at the lower border of the cribriform facia and forms a good marker of the termination of GSV and presence of the SFJ.

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2015

G. C. Nair, ,, Pradeep Jacob, Riju R. Menon, and Misha J. C. Babu, “Inflammatory diseases of the non-lactating female breasts (Original Research)”, International Journal of Surgery, vol. 13, pp. 8 - 11, 2015.[Abstract]


Chronic inflammatory diseases of the non-lactating breasts cause considerable difficulty in diagnosis and treatment. There is a spectrum of aetiological factors ranging from infection to autoimmune disorders. The disease causes considerable morbidity and psychological distress in relatively young females. The study aimed to analyse the spectrum of chronic disease and to formulate a treatment protocol. Method: Female patients with histological confirmation of inflammatory disease of the breast in the non-lactational phase were included in the study. The patients were categorized based on histological findings supplemented with immunohistochemical staining with CD3 and CD20 antibodies. Result: Out of 50 patients included in the study, 38 patients (76%) were diagnosed as idiopathic granulomatous mastitis (IGM) and 12 (24%) patients as periductal mastitis (PD). The possible aetiology of IGM was localized autoimmunity as evidenced by the infiltration of CD3 positive T lymphocyte. Systemic prednisolone was given for 6 months and 95.6% patients were disease-free after 24months. Out of 15 patients who did not receive prednisolone, only 2 patients were disease-free after 24 months (p&nbsp;=&nbsp;.003). Conclusion: Idiopathic granulomatous mastitis is an uncommon inflammatory disease of the non-lactating breast. The combination of limited surgical treatment and systemic prednisolone given for 6 months effectively controls the disease as well as prevents recurrence.

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2014

G. Nair C, ,, Pradeep Jacob, Riju R. Menon, and Misha, “Inflammatory diseases of the non-lactating female breasts”, International Journal of Surgery, vol. 13, pp. 8-11, 2014.[Abstract]


Chronic inflammatory diseases of the non-lactating breasts cause considerable difficulty in diagnosis and treatment. There is a spectrum of aetiological factors ranging from infection to autoimmune disorders. The disease causes considerable morbidity and psychological distress in relatively young females. The study aimed to analyse the spectrum of chronic disease and to formulate a treatment protocol.

Method: Female patients with histological confirmation of inflammatory disease of the breast in the non-lactational phase were included in the study. The patients were categorized based on histological findings supplemented with immunohistochemical staining with CD3 and CD20 antibodies.

Result: Out of 50 patients included in the study, 38 patients (76%) were diagnosed as idiopathic granulomatous mastitis (IGM) and 12 (24%) patients as periductal mastitis (PD). The possible aetiology of IGM was localized autoimmunity as evidenced by the infiltration of CD3 positive T lymphocyte. Systemic prednisolone was given for 6 months and 95.6% patients were disease-free after 24months. Out of 15 patients who did not receive prednisolone, only 2 patients were disease-free after 24 months (p&nbsp;=&nbsp;.003).

Conclusion: Idiopathic granulomatous mastitis is an uncommon inflammatory disease of the non-lactating breast. The combination of limited surgical treatment and systemic prednisolone given for 6 months effectively controls the disease as well as prevents recurrence.

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2014

C. G. Nair, Pradeep Jacob, Riju R. Menon, and Misha J. C. Babu, “Graves' disease in a dialysis dependent chronic renal failure patient”, Indian Journal of Nephrology, vol. 24, pp. 397-399, 2014.[Abstract]


Thyroid hormone level may be altered in chronic renal failure patients. Low levels of thyroxine protect the body from excess protein loss by minimizing catabolism. Hyperthyroidism is rarely encountered in end-stage dialysis dependent patients. Less than 10 well-documented cases of Graves' disease (GD) are reported in literature so far. We report a case of GD in a patient on dialysis.

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2013

Misha J. C. Babu, C Nair, G., Riju R. Menon, and Pradeep Jacob, “Lithium-induced parathyroid dysfunction: A new case”, Indian Journal of Endocrinology and Metabolism, vol. 17, no. 5, pp. 930-932, 2013.[Abstract]


Lithium salts are widely used in psychiatric practice and are known to induce thyroid dysfunction. Lithium-induced parathyroid dysfunction is rare. We are reporting a case of hyperparathyroidism in a 28-year-old female patient who was on lithium carbonate for 2 years, when she developed osteopenia and girdle girdle-type muscle weakness. Biochemical parameters showed hyperparathyroidism with shift of calcium creatinine clearance ratio to 0.013, indicating an error in threshold of calcium sensing receptor. The patient eventually required parathyroidectomy and the histology of the gland showed atypical features.

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2013

G. C Nair, Misha J. C. Babu, Riju R. Menon, and Pradeep Jacob, “Hypocalcaemia following total thyroidectomy: An analysis of 806 patients”, Indian Journal of Endocrinology and Metabolism, vol. 17, no. 2, pp. 298-303, 2013.[Abstract]


BACKGROUND:Permanent hypocalcaemia following thyroidectomy causes considerable morbidity. This prospective observational study aims to define the factors likely to predict hypocalcaemia following total thyroidectomy.

MATERIALS AND METHODS:Patients who were subjected to total thyroidectomy during January 2005 to December 2009 were followed up for a minimum period of 1 year. Efficacy of an intraoperative parathyroid hormone assay to predict hypocalcaemia was validated.

RESULTS:Overall incidence of hypocalcaemia was 23.6% (n = 190) and that of permanent hypocalcaemia was 1.61% (n = 13). Onset was delayed up to 3(rd) postoperative day in 13 patients. Hypocalcaemia was significantly associated with thyroidectomy for Grave's Disease (P = 0.001), Hashimoto's thyroiditis (P = 0.003), and with incidental parathyroidectomy (P = 0.006). The intraoperative assay of parathyroid hormone showed low sensitivity (0.5) and satisfactory specificity (0.9) in predicting hypocalcemia.

CONCLUSION:Hypocalcemia could manifest late in the immediate postoperative period and this may explain latent hypocalcemia. High incidence of hypocalcaemia noted in Grave's Disease could be due to the autoimmunity since same feature was noted associated with Hashimoto's thyroiditis and the incidence of hypocalcaemia was not high in the subgroup with toxic nodular goiter. The incidence of hypocalcemia was not affected by age or sex.

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2012

Misha J. C. Babu, C Nair, G., Riju R. Menon, and Pradeep Jacob, “Toxic thyroid carcinoma: A new case.”, Indian Journal of Endocrinology and Metabolism, vol. 16, no. 4, pp. 668–670, 2012.[Abstract]


Sir,
Differentiated thyroid cancer may coexist with hyperthyroidism. Cancer cell mass is less functional and appears as cold nodule in thyroid scintigraphy. Cancer cell mass rarely becomes site of excess hormone production. When thyroid cancer cell mass occupies a scintigraphically hot, functionally autonomous thyroid nodule and if thyrotoxicosis is attributable exclusively to this nodule, as shown by clinical and histologic correlation, a toxic thyroid carcinoma is diagnosed.[1] We are reporting case feature which coincides well with the above mentioned diagnosis.

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2009

Riju R. Menon, Jadhav, S., Kanthaswamy, R., Pradeep Jacob, and Nair, C. G., “Is total thyroidectomy justified in multinodular goitre”, Journal of the Indian Medical Association, vol. 107, pp. 223-225, 2009.[Abstract]


Role of total thyroidectomy in treatment of patients with benign diseases of thyroid gland remains controversial. The hypothesis behind the study is that total thyroidectomy can be performed in all benign thyroid diseases with equal rate of immediate and late complications compared with those of subtotal thyroidectomy. The retrospective case control study was done by reviewing the case records of patients with benign thyroid diseases involving both lobes operated during May, 2002 to September, 2004. The minimum follow-up period was 3 years. Of the 189 patients included in the study 94 underwent total thyroidectomy and 95 patients underwent subtotal thyroidectomy. There was no incidence of permanent recurrent laryngeal nerve paralysis in both groups. Temporary unilateral recurrent laryngeal nerve paralysis occurred in 3 patients (3.2%) in total thyroidectomy group and 1 (1.1%) patient in subtotal thyroidectomy group, which was not statistically significant (p=0.307). Temporary hypocalcaemia was noted in 10 patients of total thyroidectomy group (10.6 %) and 3 patients of subtotal thyroidectomy group (3.2%). Permanent hypocalcaemia was noted in 2 patients each in total thyroidectomy group and subtotal thyroidectomy group (p=0.991). Total thyroidectomy is an acceptable alternative to subtotal thyroidectomy in benign diseases, considering the higher rate of postoperative morbidity in recurrent goitres.

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Publication Type: Magazine Article

Year of Publication Title

2018

Riju R. Menon, Mahendran, V., and Sivadas, N., “Effect of a structured teaching program in the evaluation of and perception of Inguinal Hernia by Phase III M.B.B.S. students – A cross sectional study”, vol. 7, no. 2, 2018.[Abstract]


Background: It is a myth that the student knows the anatomy, causes, sequelae, complications and types of hernia. Though educational tools for the surgical procedure are available but a structured teaching format is not described in literature. A structured methodology of teaching may help in improving the knowledge of the student.
Methods: A cross sectional study was done at our institution using 37 Phase III MBBS students. A pre-test was followed by a structured methodology of teaching students about inguinal hernia. A post-test and feedback was taken after 2 days. Data was computed. Statistical significance was found by using non-parametric test – Wilcoxon Signed-Ranks test. The quantitative data were expressed as Mean ± SD and qualitative data were expressed as frequency and proportions.
Results: Mean marks of the students were 4.37 and 5.11 among 8th and 9th semester students which improved to 15.04 and 14.33 marks which was statistically very highly significant with p = 0.0001 and 0.008 respectively which showed a gain in knowledge of students.
Conclusion: Structured teaching improves the ability of an IMG to diagnose hernia. Objective Structured Teaching
Evaluation (OSTE) will help the teacher, whether junior or senior, learn to be a better teacher.

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Publication Type: Book

Year of Publication Title

2015

S. Vaidyanathan, Riju R. Menon, Pradeep Jacob, and John, B., Chronic Venous Disorders of the Lower Limbs. New Delhi, India: Springer, New Delhi, 2015.[Abstract]


Chronic venous disorders are a major health problem due to their wide prevalence and socio-economic considerations. This book is a comprehensive manual providing state- of- the- art information on the diagnosis and management of these common problems. Till recently venous disorders have been getting secondary attention as compared to their arterial counterpart. However, the last two decades witnessed major technological advancements and therapeutic strategies for these problems. Written with a surgical perspective, this monograph covers the latest developments and recommended procedures in an easy-to-read format guiding the surgeon to prepare a rational treatment plan. Supplemented with numerous figures and illustrations, the chapters update the readers with how to evaluate such patients in their practices, selection criteria for appropriate procedures and how to manage the complications. The book includes basics of venous disorders, primary varicose veins and recurrence after surgery, chronic venous insufficiency, venous ulcers and congenital venous malformations. Detailed coverage of endo-venous procedures such as radio-frequency ablation, laser ablation and foam sclerotherapy are additional essential features of this book. Primarily intended for the practicing general surgeon, this volume is also relevant for residents in general surgery and vascular surgery.

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