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Mishra, Nitin

https://orcid.org/0000-0003-4450-7682

Mayo Clinic

Mayo Clinic

Citations 7

Room for improvement? Evaluating the accuracy of referrals for rectal prolapse to three tertiary care medical centres
Alatout, Mayar H , Saleeb, Andrew G. , Hor, Hoe Yan , Young‐Fadok, Tonia M., Mishra, Nitin , Etzioni, David A. , Shawki, S. F., Merchea, A., Brady, Justin T, Mansour, Rania , Young-Fadok, Tonia M, Shawki, Sherief , Brady, Justin T , Alatout, Mayar H., Merchea, Amit , Brady, Justin T.

Colorectal Disease | March 8, 2026 | Volume: 28 | Issue: 3 | Pages: No page available

10.1111/codi.70418 Get It

Abstract Aim Rectal prolapse is a full‐thickness intussusception of the rectum beyond the anal canal. It is often mistaken for other anorectal pathologies, leading to inaccurate referrals to colorectal surgeons and inappropriate management. However, the frequency of misdiagnosis is not well characterized. We aimed to assess the diagnostic accuracy of rectal prolapse referrals to three tertiary medical centres. Methods This is a retrospective study of patients referred for rectal prolapse to colorectal surgeons at the Mayo Clinic in Rochester, Jacksonville, and Phoenix from 2020 to 2024. The primary outcome is the accuracy of rectal prolapse diagnosis. The secondary outcomes are factors that correlate with diagnostic accuracy. Results Rectal prolapse was inaccurately diagnosed in 38.7% (186/480) of patients. Among misdiagnosed patients, the correct diagnosis was haemorrhoids (68.0%, n = 134), pelvic floor dysfunction (24.3%, n = 48) and rectocele (18.7%, n = 37). A diagnosis of rectal cancer was found in 3 patients (1.5%). The most common presenting symptoms were protrusion (66.3%, n = 345) and bleeding (33.6%, n = 175). Among the referring physicians, only 50.5% ( n = 227) performed an anorectal examination. Overall, there was significant variability in diagnostic accuracy across different specialties, with the highest accuracy from colorectal practices (84.0%) and the lowest from urologists (50.0%). Internal medicine physicians had a lower diagnostic accuracy with anorectal examination than without, though it did not reach statistical significance (44.0% vs. 59.5%, p = 0.2). Conclusion Over one‐third of rectal prolapse referrals were incorrectly diagnosed. This study highlights the opportunity for further training of referring providers on anorectal pathologies to improve diagnostic accuracy which could reduce treatment delays and optimize clinical outcomes.
Individualized Learning in Robotic Ileal pouch-anal anastomosis
Violante, Tommaso , Sassun, Richard , Mishra, Nitin , Merchea, Amit , Violante, Tommaso , Sassun, Richard , Ferrari, Davide, Behm, Kevin T. , Vierkant, Robert A. , Larson, David W.

Annals of Surgery | August 12, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1097/sla.0000000000006907 Get It

Objective: This study establishes objective benchmarks for robotic ileal pouch-anal anastomosis (IPAA) proficiency, evaluating individual surgeon learning curves using risk-adjusted cumulative sum (RA-CUSUM) analysis. Summary Background Data: IPAA is a standard surgical treatment for conditions like refractory ulcerative colitis; robotic assistance offers potential advantages. However, the robotic IPAA learning curve is not clearly defined. Conventional analyses often overlook significant inter-surgeon variability and patient-specific factors, hindering surgical training optimization. Methods: A multi-site retrospective analysis of 123 consecutive robotic IPAA procedures performed by 11 surgeons between June 2015 and December 2023 was conducted. Patient-related variables were used for risk adjustment, and RA-CUSUM charts were generated to assess 30-day complications, operative time, and length of hospital stay at both aggregate and individual surgeon levels. Results: Aggregate RA-CUSUM data indicated general improvement trends for operative time and length of stay, alongside higher-than-expected complication rates in the early phase. Disaggregated analyses at the individual surgeon level revealed significant heterogeneity in performance trajectories and learning patterns across all three outcomes, directly challenging the concept of a standardized, uniform learning curve. Although postoperative complication and length of stay outcomes did not significantly differ between surgeons, operative time varied significantly. Conclusions: The acquisition of skill in robotic IPAA is a highly individualized process, suggesting the traditional uniform learning curve model is insufficient for contemporary surgical education. These findings strongly advocate for a shift towards personalized training paradigms that incorporate deliberate practice, targeted feedback, and simulation to optimize learning and patient outcomes.
Ionic Liquid‐Reinforced Multifunctional Hydrogel for the Treatment of Enterocutaneous Fistula
Keum, Hyeongseop , Albadawi, Hassan , Altinbasak, Ismail , Yavuz, Furkan, Mishra, Nitin , Öklü, Rahmi , Kim, Jinjoo , Oklu, Rahmi , Graf, Erin H.

Advanced Materials | May 12, 2025 | Volume: 37 | Issue: 29 | Pages: No page available

10.1002/adma.202503179 Get It

AbstractEnterocutaneous fistulas (ECFs) profoundly impact patients’ quality of life, contributing to high morbidity rates and increased mortality due to ineffective treatment options. To address this challenge, ECFGel, a multifunctional, tissue adhesive injectable hydrogel, designed to occlude, sterilize, and promote healing of ECF tracts, is developed. ECFGel is formulated using gelatin and oxidized dextran (O‐Dex) as base components, which form chemical crosslinks within the hydrogel and with surrounding biological tissues, ensuring tissue adhesiveness. A choline and geranate‐based ionic liquid (IL) is incorporated to provide dual functionality, potent antimicrobial activity, and mechanical enhancement. By optimizing IL concentration, ECFGel achieves rapid gelation, enhanced mechanical strength, and improved elastic recoverability. Additionally, iohexol (IOH) is added for radiopacity, enabling real‐time imaging and further strengthening the hydrogel's mechanical properties. ECFGel demonstrates antiswelling properties, biodegradability, and effective tract occlusion in porcine soft tissues. It shows strong antimicrobial activity against highly resistant, patient‐derived pathogens isolated from clinical ECF cases. In a porcine perianal fistula model, ECFGel enables rapid occlusion and complete healing, promoting tissue maturation, reducing bacterial load, and increasing markers of cell proliferation and vascularization compared to untreated controls. These promising results highlight ECFGel's potential as a new therapeutic option for treating infected ECFs.
Multiple robotic stapler firings to transect the rectum are not associated with anastomotic leakage
Cardelli, Stefano , Stocchi, Luca , Merchea, Amit , DeLeon, Michelle , Mishra, Nitin , Hancock, Kevin , DeLeon, Michelle F, Hancock, Kevin J , Colibaseanu, Dorin , Larson, David W.

Colorectal Disease | May 3, 2025 | Volume: 27 | Issue: 5 | Pages: No page available

10.1111/codi.70094 Get It

AbstractAimThe relationship between the number of stapler firings (SFs) during robotic rectal transection and the risk of colorectal/coloanal anastomotic leakage (AL) is controversial. This study investigates whether the number of robotic SFs is associated with an increased risk of AL.MethodRetrospective review of adult patients who underwent robotic total mesorectal excision (TME) and partial mesorectal excision (PME) with double‐stapled colorectal or coloanal anastomosis for both benign and malignant colorectal diseases between 2015 and 2023 across three enterprise‐wide hospitals. Primary outcome: the effect of multiple SFs on postoperative AL rate among patients who underwent one, two, or three or more SFs. Secondary outcome: the effects of other potential risk factors on postoperative AL.ResultsOf 503 patients who underwent robotic colorectal resection with a double‐stapled anastomosis, 56 (11%) developed a postoperative AL. The number of SFs was not associated with the AL rate (p = 0.51): the univariable and multivariate analyses found no correlation between the AL rate and the increasing number of SFs required, compared with one SF as the reference (adjusted two SFs, OR = 1.1, 95% CI: 0.6–2.2, p = 0.77 vs. adjusted three or more SFs, OR = 0.98, 95% CI: 0.4–2.3, p = 0.96). On multivariate analysis, AL was strongly associated with male gender (OR = 2.5, 95% CI: 1.3–4.9, p = 0.005) and with TME versus PME (OR = 2.8, 95% CI: 1.5–5.5, p = 0.002).ConclusionThe number of robotic SFs for rectal transection is not correlated with postoperative AL.
Comparative Outcomes of Robotic Versus Open Proctectomy for Rectal Cancer at High Risk of Positive Circumferential Resection Margin
Cardelli, Stefano , Stocchi, Luca , Merchea, Amit , Colibaseanu, Dorin , DeLeon, Michelle , Mishra, Nitin , Hancock, Kevin , Larson, David W. , Colibaseanu, Dorin T , DeLeon, Michelle F, Hancock, Kevin J , Larson, David W

Diseases of the Colon & Rectum | August 6, 2024 | Volume: 67 | Issue: 11 | Pages: 1475-1484

10.1097/dcr.0000000000003466 Get It

BACKGROUND: Concerns persist regarding the effectiveness of robotic proctectomy compared with open proctectomy for locally advanced rectal cancer with a high risk of circumferential resection margin involvement. OBJECTIVE: Comparison of surrogate cancer outcomes after robotic versus open proctectomy in this subpopulation. DESIGN: Retrospective cohort study. SETTING: Three academic hospitals (Mayo Clinic Arizona, Florida, and Rochester) with data available through the Mayo Data Explorer platform. PATIENTS: Patients at high risk of circumferential resection margin involvement were selected on the basis of the MRI-based definition from the MERCURY I and II trials. MAIN OUTCOME MEASURES: Rate of pathologic circumferential resection margin involvement (≤1 mm), mesorectal grading, and rate of distal margin involvement. RESULTS: Out of 413 patients, 125 (30%) underwent open and 288 (70%) underwent robotic proctectomy. Open proctectomy was significantly associated with a greater proportion of cT4 tumors (39.3% vs 24.8%, p = 0.021), multivisceral/concomitant resections (40.8% vs 18.4%, p < 0.001), and less frequent total neoadjuvant therapy use (17.1% vs 47.1%, p = 0.001). Robotic proctectomy was less commonly associated with pathologic circumferential resection margin involvement (7.3% vs 17.6%, p = 0.002), including after adjustment for cT stage, neoadjuvant therapy, and multivisceral resection (OR 0.326; 95% CI, 0.157–0.670, p = 0.002). Propensity score matching for 66 patients per group and related multivariable analysis no longer indicated any reduction of circumferential positive margin rate associated with robotic surgery ( p = 0.86 and p = 0.18). Mesorectal grading was comparable (incomplete mesorectum in 6% robotic proctectomy patients vs 11.8% open proctectomy patients, p = 0.327). All cases had negative distal resection margins. LIMITATION: Retrospective design. CONCLUSIONS: In patients with locally advanced rectal cancer at high risk of circumferential resection margin involvement, robotic proctectomy is an effective approach and could be pursued when technically possible as an alternative to open proctectomy. See Video Abstract . RESULTADOS COMPARATIVOS ENTRE LA PROCTECTOMÍA ROBÓTICA Y LA PROCTECTOMÍA ABIERTA EN CASOS DE CÁNCER DE RECTO CON ALTO RIESGO DE MÁRGEN DE RESECCIÓN CIRCUNFERENCIAL POSITIVO ANTECEDENTES: Persisten preocupaciones con respecto a la efectividad de la proctectomía robótica en comparación con la proctectomía abierta en casos de cáncer de recto localmente avanzado con un alto riesgo de margen de resección circunferencial positivo. OBJETIVO: Comparar los resultados en la subpoblación de portadores de cáncer luego de una proctectomía robótica versus una proctectomía abierta. DISEÑO: Estudio retrospectivo de cohortes. AJUSTE: Realizado en tres hospitales académicos (Mayo Clinic de Arizona, Florida y Rochester) a través de la plataforma Mayo Data Explorer. PACIENTES: Fueron seleccionados aquellos pacientes con alto riesgo de compromiso sobre el margen de resección circunferencial, según la definición de los Estudios Mercury I-II basada en la Imágen de Resonancia Magnética. MEDIDAS DE RESULTADO PRINCIPALES Y SECUNDARIAS: La tasa de compromiso patológico sobre el margen de resección circunferencial (≤1 mm), la clasificación mesorrectal y la tasa del compromiso del margen distal. RESULTADOS: De 413 pacientes, 125 (30%) fueron sometidos a una proctectomía abierta y 288 (70%) a proctectomía robótica. La proctectomía abierta se asoció significativamente con una mayor proporción de tumores cT4 (39,3% frente a 24,8%, p = 0,021), las resecciones multiviscerales/concomitantes fueron de 40,8% frente a 18,4%, p < 0,001 y una adminstración menos frecuente de terapia neoadyuvante total (17,1). % vs 47,1%, p = 0,001). La proctectomía robótica se asoció con menos frecuencia con la presencia de una lesión sobre el margen de resección circunferencial patológico (7,3% frente a 17,6%, p = 0,002), incluso después del ajuste por estadio cT, de la terapia neoadyuvante y de resección multivisceral (OR 0,326, IC 95% 0,157-0,670, p = 0,002). El apareado de propensión por puntuación en 66 pacientes por grupo y el análisis multivariable relacionado, no mostraron ninguna reducción en la tasa de margen positivo circunferencial asociado con la cirugía robótica ( p = 0,86 y p = 0,18). La clasificación mesorrectal fue igualmente comparable (mesorrecto incompleto en el 6% de los pacientes con RP frente al 11,8% de los pacientes con OP, p = 0,327). Todos los casos tuvieron márgenes de resección distal negativos. LIMITACIÓN: Diseño retrospectivo. CONCLUSIÓN: En pacientes con cáncer de recto localmente avanzado con alto riesgo de compromiso del margen de resección circunferencial, la proctectomía robótica es un enfoque eficaz y podría realizarse cuando sea técnicamente posible como alternativa a la proctectomía abierta. (Traducción—Dr. Xavier Delgadillo )
Management of Acute Diverticulitis in Immunocompromised Patients—The Mayo Clinic Experience
He, Shengliang, Lu, Patricia G , Etzioni, David A. , Young‐Fadok, Tonia M., Merchea, Amit , Mishra, Nitin , Lu, Patricia, Etzioni, David, Young-Fadok, Tonia, Kelley, Scott R.

Diseases of the Colon & Rectum | July 19, 2022 | Volume: 66 | Issue: 3 | Pages: 434-442

10.1097/dcr.0000000000002447 Get It

BACKGROUND: Acute diverticulitis in immunocompromised patients is associated with high morbidity and mortality rates with either medical or surgical treatment. Thus, management approach is controversial, especially for patients presenting with nonperforated disease. OBJECTIVE: This study aimed to report the Mayo clinic experience of acute diverticulitis management in immunocompromised patients. DESIGN: This design is based on a retrospective cohort study. SETTING: This study was conducted with institutional data composed from 3 tertiary referral centers. PATIENTS: Immunocompromised patients presenting with acute diverticulitis at 3 Mayo clinic sites between 2016 and 2020 were included. MAIN OUTCOME MEASURES: The main outcome measures were the management algorithm and short-term outcomes. RESULTS: Immunocompromised patients presenting with acute uncomplicated diverticulitis (86) were all managed nonoperatively at presentation with a success rate of 93% (80/86). Two patients (2.3%, 2/86) required surgery during the same admission, and 4 patients (4.8%, 4/84) had 30-day readmission. Complicated diverticulitis patients with abscess (22) were all managed nonoperatively first with a success rate of 95.4% (21/22). One patient (4.6%, 1/22) required surgery during the same admission. All the patients who presented with obstruction (2), fistula (1), or free perforation (11) underwent surgery except one who chose hospice. Overall, the major complication rate was 50% (8/16) and mortality rate was 18.8% (3/16) among patients who underwent surgery during the same admission. For patients who presented with perforated diverticulitis, the mortality rate was 27.3% (3/11), compared with 0% (0/111) for patients who presented with nonperforated disease. LIMITATIONS: This cohort was limited by its retrospective nature and heterogeneity of the patient population. CONCLUSIONS: Nonoperative management was safe and feasible for immunocompromised patients with colonic diverticulitis without perforation at our center. Perforated colonic diverticulitis in immunocompromised patients was associated with high morbidity and mortality rate. See Video Abstract at http://links.lww.com/DCR/B988. MANEJO DE LA DIVERTICULITIS AGUDA EN PACIENTES INMUNOCOMPROMETIDOS: EXPERIENCIA DE LA CLINICA MAYO ANTECEDENTES: La diverticulitis aguda en pacientes inmunocomprometidos se asocia con una alta tasa de morbilidad y mortalidad con el tratamiento médico o quirúrgico. Por lo tanto, el enfoque de manejo es controvertido, especialmente para pacientes que presentan enfermedad no perforada. OBJETIVO: El propósito fue informar la experiencia de la clínica Mayo en el manejo de la diverticulitis aguda en pacientes inmunocomprometidos. DISEÑO: Este es un estudio de cohorte retrospectivo ENTORNO CLÍNICO: Este estudio se realizó con datos institucionales compuestos de tres centros de referencia terciarios. PACIENTES: Se incluyeron pacientes inmunocomprometidos que presentaron diverticulitis aguda en tres sitios de la clínica Mayo entre 2016 y 2020. RESULTADO PRINCIPAL: Algoritmo de gestión y resultados a corto plazo. RESULTADOS: Los pacientes inmunocomprometidos que presentaban diverticulitis aguda no complicada (86) fueron tratados de forma no quirúrgica en la presentación inicial con una tasa de éxito del 93 % (80/86). Dos pacientes (2,3%, 2/86) requirieron cirugía durante el mismo ingreso y cuatro pacientes (4,8%, 4/84) tuvieron reingreso a los 30 días. Todos los pacientes con diverticulitis complicada con absceso (22) fueron tratados primero de forma no quirúrgica con una tasa de éxito del 95,4 % (21/22). Un paciente (4,6%, 1/22) requirió cirugía durante el mismo ingreso. Todos los pacientes que presentaron obstrucción (2), fístula (1) o perforación libre (11) fueron intervenidos excepto uno que optó por hospicio. La tasa global de complicaciones mayores fue del 50 % (8/16) y la tasa de mortalidad fue del 18,8 % (3/16) entre los pacientes que se sometieron a cirugía durante el mismo ingreso. Para los pacientes que presentaban diverticulitis perforada, la tasa de mortalidad fue del 27,3 % (3/11), en comparación con el 0 % (0/111) de los pacientes que presentaban enfermedad no perforada. LIMITACIONES: Esta cohorte estuvo limitada por su naturaleza retrospectiva y la heterogeneidad de la población de pacientes. CoNCLUSIÓNES: El manejo no quirúrgico fue seguro y factible para pacientes inmunocomprometidos con diverticulitis colónica sin perforación en nuestro centro. La diverticulitis colónica perforada en pacientes inmunocomprometidos se asoció con una alta tasa de morbilidad y mortalidad. Consulte Video Resumen en http://links.lww.com/DCR/B988. (Traducción— Dr. Ingrid Melo)
Colon perforation in multiple myeloma patients – A complication of high‐dose steroid treatment
Vaxman, Iuliana , Kumar, Shaji , Mishra, Nitin , Dingli, David , Lacy, Martha Q. , Muchtar, Eli , Hobbs, Miriam, Fonder, Amie , Hwa, Yi L. , Kapoor, Prashant , Siddiqui, Mustaqeem , Lust, John A., Kyle, Robert A. , Hayman, Suzanne R. , Kourelis, Taxiarchis , Warsame, Rahma , Al Saleh, Abdullah S , Nitin, Mishra, Lacy, Martha, Muchtar, E , Hwa, Lisa, Visram, Alissa , Lust, John, Rajkumar, Vincent, Gertz, Morie A , Vaxman, Iuliana , Siddiqui, Mustaqeem A , Dingli, David , Saleh, Abdullah S. Al , Dispenzieri, Angela , Buadi, Francis K. , Rajkumar, S. Vincent , Leung, Nelson , Gonsalves, Wilson I. , Gertz, Morie A.

Cancer Medicine | October 6, 2020 | Volume: 9 | Issue: 23 | Pages: 8895-8901

10.1002/cam4.3507 Get It

Abstract Gastrointestinal complications of multiple myeloma (MM) treatment are common and include nausea, constipation, and diarrhea. However, acute gastrointestinal events like perforations are rare. We aimed to describe the characteristics and outcomes of patients with MM that had colonic perforations during their treatment. This is a retrospective study that included patients from all three Mayo Clinic sites who had MM and developed a colonic perforation. All patients were diagnosed with colonic perforations based on CT scans and were surgically treated. Patients diagnosed with AL amyloidosis, a perforated colon complicating neutropenic colitis during ASCT and those with perforation due to colonic cancer were excluded. A high dose of dexamethasone was defined as ≥40 mg dexamethasone once a week. Thirty patients met inclusion criteria. All patients received steroids at doses ≥10 mg once weekly prior to the perforation, while four (11%) were on high‐dose dexamethasone without chemotherapy. Fourteen patients were given high doses of dexamethasone. Twenty‐five patients required ostomies with all surviving surgery. Twenty‐four perforations (80%) were associated with diverticulitis. Treatment with steroids was resumed in 23 patients with no further gastrointestinal complications. The median OS was 20 months following perforation (IQR 8–59). Within the same timeframe 5854 patients were treated at Mayo Clinic for MM, making the risk of bowel perforation 0.5%. Intestinal perforations in MM are rare and, in our series, always occurred with dexamethasone ≥10 mg per week. Urgent surgery is lifesaving and resumption of anti‐myeloma treatment appears to be safe.