Immediate sphincter repair following fistulotomy for anal fistula: does it impact the healing rate and septic complications?

PURPOSE: Fistulotomy is considered the most effective treatment for anal fistula; however, it carries a risk of incontinence. Sphincteroplasty in the setting of fistulotomy is not standard practice due to concerns regarding healing and potential infectious complications. We aimed to compare the outcomes of patients who underwent fistulotomy with primary sphincteroplasty to those who did not undergo repair. METHODS: This was a retrospective review of consecutive patients who underwent fistulotomy for cryptoglandular anal fistula. All operations were performed by one colorectal surgeon. Sphincteroplasty was performed for patients perceived to be at higher risk for continence disturbance. The main outcome measures were the healing rate and postoperative septic complications. RESULTS: In total, 152 patients were analyzed. Group A (fistulotomy with sphincteroplasty) consisted of 45 patients and group B (fistulotomy alone) included 107 patients. Both groups were similar in age (P=0.16) and sex (P=0.20). Group A had higher proportions of multiple fistulas (26.7% vs. 6.5%, P<0.01) and complex fistulas (mid to high transsphincteric, 37.8% vs. 10.3%; P<0.01) than group B. The median follow-up time was 8 weeks. The overall healing rate was similar in both groups (93.3% vs. 90.6%, P=0.76). No significant difference between the 2 groups was noted in septic complications (6.7% vs. 3.7%, P=0.42). CONCLUSION: Fistulotomy with primary sphincter repair demonstrated a comparable healing rate to fistulotomy alone, without an increased risk of postoperative septic complications. Further prospective randomized studies are needed to confirm these findings and to explore the functional outcomes of patients who undergo sphincteroplasty.

Optimum management for complex anal fistula: A network meta-analysis of randomized controlled trials.

Background: Complex anal fistula has a high recurrence rate and disturbing surgical complications, which are frustrating for patients and challenging for surgeons. Although single or combined management methods have produced positive outcomes, no trials have simultaneously compared these therapies. Therefore, this study aimed to determine the management method for complex anal fistula with the lowest failure and complication rates. Methods: This network meta-analysis (NMA) was registered in the international prospective register of systematic reviews (PROSPERO; CRD42023393349). Randomized controlled trials that analyzed complex anal fistula management were obtained from Medline, Scopus, and Cochrane using representative keywords. The primary outcome was the failure of anal fistulas to heal (including recurrences) after 6 to 12 months. The secondary outcome was fecal incontinence. All statistical analysis was conducted within the Bayesian framework using BUGSnet 1.1.0 in R Studio. A forest plot and league table were used to present the results. Results: A total of 19 studies containing 15 interventions, 1844 subjects, and 104 pairwise comparisons were analyzed quantitatively. The lowest failure rates occurred with ligation of the intersphincteric fistula tract (LIFT) + Plug (RR 0.2; 95 % CI 0.01-2.65), LIFT + platelet-rich plasma (PRP) (RR 0.22; 95 % CI 0.01-2.89), and FSR (RR 0.26; 95 % CI 0.02-2.12) relative to drainage seton. LIFT combined with other management methods showed lower fecal incontinence rates than the other treatments. Conclusion: The combination of LIFT with plug or PRP resulted in lower failure and complication rates in the management of complex anal fistula compared to the other methods tested.

Transanal opening of the intersphincteric space (TROPIS): a novel procedure on the horizon to effectively manage high complex anal fistulas.

Anal fistulas, especially complex and high fistulas, are difficult to manage. The transanal opening of the intersphincteric space (TROPIS) procedure was first described in 2017, and a high success rate of over 90% was reported in high complex fistulas. Since then, more studies and even a meta-analysis have corroborated the high efficacy of this procedure in high fistulas. Conventionally, the main focus was to close the internal (primary) opening for the fistula to heal. However, most complex fistulas have a component of the fistula tract in the intersphincteric plane. This component is like an abscess (sepsis) in a closed space (2 muscle layers). It is a well-known fact that in the presence of sepsis, healing by secondary intention leads to better results than attempting to heal by primary intention. Therefore, TROPIS is the first procedure in which, instead of closing the internal opening, the opening is widened by laying open the fistula tract in the intersphincteric plane so that healing can occur by secondary intention. Although the drainage of high intersphincteric abscesses through the transanal route was described 5 decades ago, the routine utilization of TROPIS for the definitive management of high complex fistulas was first described in 2017. The external anal sphincter (EAS) is completely spared in TROPIS, as the fistula tract on either side of the EAS is managed separately-inner (medial) to the EAS by laying open the intersphincteric space and outer (lateral) to the EAS by curettage or excision.

Fístula enterocutánea: un enfoque desde las generalidades y el estado nutricional / Enterocutaneous fistula: An approach based on generalities and nutritional status

Introducción. Una fístula es una conexión anormal entre dos superficies epitelizadas. Cerca del 80 % de las fístulas entero-cutáneas son de origen iatrogénico secundarias a cirugía, y un menor porcentaje se relacionan con traumatismos, malignidad, enfermedad inflamatoria intestinal o isquemia. La morbilidad y las complicaciones asociadas pueden ser significativas, como la desnutrición, en la que intervienen múltiples factores. Métodos. Se realizó una búsqueda de la literatura en las bases de datos de PubMed, Google Scholar y SciELO, utilizando las palabras claves descritas y se seleccionaron los artículos más relevantes de los últimos años. Resultados. La clasificación de las fístulas se basa en su anatomía, su gasto o secreción diaria y su localización. Existe una tríada clásica de las complicaciones: sepsis, desnutrición y anomalías electrolíticas. El control del gasto de la fístula, el drenaje adecuado de las colecciones y la terapia antibiótica son claves en el manejo precoz de estos pacientes. Los estudios recientes hacen hincapié en que la sepsis asociada con la desnutrición son las principales causas de mortalidad. Conclusiones. Esta condición representa una de las complicaciones de más difícil y prolongado tratamiento en cirugía abdominal y colorrectal, y se relaciona con importantes tasas de morbilidad, mortalidad y altos costos para el sistema de salud. Es necesario un tratamiento multidisciplinario basado en la reanimación con líquidos, el control de la sepsis, el soporte nutricional y el cuidado de la herida, entre otros factores.

Introduction. A fistula is an abnormal connection between two epithelialized surfaces. About 80% of enterocutaneous fistulas are of iatrogenic origin secondary to surgery, and a smaller percentage are related to trauma, malignancy, inflammatory bowel disease or ischemia. The associated morbidity and complications can be significant, such as malnutrition, in which multiple factors intervene. Methods. A literature search was carried out in the PubMed, Google Scholar and SciELO databases using the keywords described and the most relevant articles from recent years were selected. Results. The classification of fistulas is based on their anatomy, their daily secretion output, and their location. There is a classic triad of complications: sepsis, malnutrition and electrolyte abnormalities. Control of fistula output, adequate drainage of the collections and antibiotic therapy are key to the early management of these patients. Recent studies emphasize that sepsis associated with malnutrition are the main causes of mortality. Conclusions. This condition represents one of the most difficult and prolonged complications to treat in abdominal and colorectal surgery, and is related to significant rates of morbidity, mortality and high costs for the health system. Multidisciplinary treatment based on fluid resuscitation, sepsis control, nutritional support, and wound care, among other factors, is necessary.

Posterior median surgical approach to anterior sacral meningocele complicated by rectothecal fistula.

In this case report, we aimed to describe the clinical presentation, surgical approach, and follow-up of a patient with rare anterior meningocele associated with rectothecal fistula. An 17-year-old female patient was admitted to the emergency department with meningitis. On further examinations, an anterior sacral meningocele accompanied by rectothecal fistula was detected. Appropriate antibiotic treatment was arranged and surgical plan was made with the pediatric surgery clinic. The patient underwent meningocele repair via posterior approach and colostomy operation. The patient did not experience any neurological issues after the surgery. The colostomy was reversed 3 months later, and third-month follow-up MRI showed complete regression of the meningocele sac with no neurological complications. Anterior meningocele accompanied by a rectothecal fistula is a rare and complicated case. Only seven cases of coexisting ASM and RTF have been reported in literature. Although both anterior and posterior approaches have been used for the treatment of ASM, the choice of treatment is essentially based on the patient's clinical and imaging findings.

Distalization of perianal fistulas after loose silicone seton drainage is a myth.

BACKGROUND: It is often stated that loose seton drainage results in distal migration of a fistula tract in perianal fistula. The aim of the present study was to assess this distalization of trans- and suprasphincteric perianal fistulas after a silicone seton has been inserted. METHODS: Consecutive patients who underwent loose seton placement for the management of a transsphincteric or suprasphincteric fistula between January 2016 and December 2021 with a pre- and postoperative magnetic resonance imaging (MRI) were included in the present retrospective study. The height of the external anal sphincter (EAS) and the level of penetration of perianal fistula through the EAS or puborectal muscle (PRM) were determined on MRI. Primary outcome was migration of the fistula tract through the EAS and PRM. RESULTS: Thirty-eight patients with perianal fistulas were included. Median height of the EAS was 28 (IQR 25-34) mm before seton placement and 27 (IQR 24-33) mm afterward. Median level of perforation was 32 (IQR 17-40) mm before seton placement and 28 (IQR 17-40) mm afterward (p = 0.37). One fistula (3%) was downgraded from mid to low transsphincteric and was laid open after 14.9 months of loose seton drainage. CONCLUSIONS: No statistically significant distalization of complex fistula tracts after loose silicone seton drainage was found. Some complex fistulas may downgrade to a less complex fistula after long-term seton drainage. However, loose silicone seton drainage should not be offered to patients as a treatment option to downgrade a complex fistula to a simple one or even have the hope to heal it.

Pneumorrhachis Secondary to a Locally Advanced Rectal Cancer with Pre-Sacral Abscess-Case Report and Review.

The occurrence of pneumorrhachis (PR), defined as the presence of air within the spinal canal, presents a complex clinical picture with diverse etiological factors. We report an exceedingly rare case of PR arising from locally advanced rectal cancer accompanied by a pre-sacral abscess. This report aims to enhance awareness and understanding of rare causes of PR within the medical community, particularly among surgeons engaged in emergency procedures. The patient survived the acute phase of the disease through multiple surgical interventions and admission to the intensive care unit, but succumbed to cardiovascular complications three weeks later. We also offer a brief review of the literature concerning PR originating from the colorectal lumen.

Clinical research progress in Traditional Chinese Medicine in treating wound healing after anal fistula surgery.

In the study of the mechanism of wound healing after anal fistula surgery, how to scientifically and efficiently promote wound healing is of great significance. At present, modern medical treatment of wounds after anal fistula surgery mostly focuses on physical therapy intervention, new wound dressing and packing, and external application of growth factors. However, these therapies have many problems, and there is still no consensus on their clinical use. Traditional Chinese Medicine (TCM) has several methods to promote wound healing, such as oral administration, rubbing, and fumigation, which have a long history and obvious efficacy, but research in this area is relatively scattered and lacks classification and summarizing. Therefore, this paper analyzes and summarizes the existing research on TCM for promotion of wound healing after anal fistula surgery, carries out targeted analyses according to different clinical syndromes and treatment methods, and analyzes the defects in current research and anticipates future research trends in order to provide theoretical support for the advantages of TCM in promoting wound healing after anal fistula surgery.

Nutritional status in perianal Crohn's disease: are we underestimating the impact?

Symptomatic perianal disease is common in patients with Crohn's disease (CD), and perianal fistulas represent the primary form of anal involvement. This type of involvement is associated with a poor prognosis and a disabling course. The treatment is challenging and involves both surgical and medical approaches. Despite combined therapy, a significant portion of patients may still require proctectomy to control the symptoms. Consequently, investigating factors that may influence the outcome of perianal disease remains a priority area of research in CD. Nutritional deficiencies are well documented among CD patients with luminal forms of involvement and are closely related to poor clinical outcomes, therapy response, and postoperative complications. As a result, leading guidelines recommend regular nutritional assessment and correction of nutritional deficiencies in patients requiring a surgical approach. Despite these recommendations and the high rate of surgeries among CD patients with perianal disease, there is a shortage of studies addressing the real impact of nutritional status on the course and outcomes of perianal disease. This knowledge gap underscores the importance of further research to understand better and improve the management of perianal CD. This narrative review aims to provide an overview of nutritional status assessment and the influence of nutritional status on the outcomes of patients with perianal CD.

[Anal fistulas: Sparing the sphincter]. / Fistules anales, épargner le sphincter.

ANAL FISTULAS: SPARING THE SPHINCTER. Fistulotomy is the most used treatment for anal fistula. It is very effective with a cure rate of over 95% but carries a risk of incontinence. This has led to the development of various sphincter sparing techniques. The injection of biological glue or paste and the insertion of a plug have disappointing results and are expensive. The rectal advancement flap is still practised because of its cure rate of around 75% but it may result in some incontinence. Intersphincteric ligation of the fistula track and laser treatment are widely practised in France with cure rates between 60 and 70%. Video-assisted anal fistula treatment as well as injections of adipose tissue, stromal vascular fraction, platelet-enriched plasma and/or mesenchymal stem cells are emerging techniques for which even better results are expected.

FISTULES ANALES, ÉPARGNER LE SPHINCTER. La fistulotomie est le traitement le plus souvent utilisé dans la fistule anale. Elle est très efficace, avec un taux de guérison supérieur à 95 %, mais expose à un risque d'incontinence. Cela a conduit au développement de diverses techniques d'épargne sphinctérienne. L'injection de colle ou de pâte biologique ainsi que la mise en place d'un plug ont des résultats finalement décevants et un coût élevé. Le lambeau rectal d'avancement est encore pratiqué en raison de son taux de guérison aux alentours de 75 %, mais il peut se solder par quelques troubles séquellaires de la continence. La ligature intersphinctérienne du trajet fistuleux et le laser sont largement pratiqués en France, avec des taux de guérison oscillant entre 60 et 70 %. Le traitement vidéo-assisté du trajet fistuleux ainsi que les injections périfistuleuses de tissu adipeux, de fraction vasculaire stromale, de plasma enrichi en plaquettes et/ou de cellules souches mésenchymateuses sont des techniques émergentes dont on espère de meilleurs résultats encore.

State-of-the-art surgery for Crohn's disease: part III-perianal Crohn's disease.

PURPOSE: Diagnosis and treatment of perianal Crohn's disease is challenging and requires its own domain of therapy. Different types of perianal disease require a spectrum of treatment strategies. Treatment options range from conservative therapy, including immunosuppressives, biologics, or stem cell therapy, to surgical treatment with specific indications depending on the underlying lesion. This is part III of the series "state-of-the-art surgery for Crohn's disease," focusing on the management of perianal disease. We discuss the definition and diagnosis of perianal Crohn's disease, the treatment of perianal lesions, and specific surgical indications and techniques. RESULTS AND CONCLUSION: Pitfalls and complications play a substantial role in the treatment of perianal Crohn's disease, and surgical therapy may fail. Realistic treatment goals and an individual patient-oriented treatment approach are crucial in the treatment of perianal Crohn's disease.

Three-dimensional modelling as a novel interactive tool for preoperative planning for complex perianal fistulas in Crohn's disease.

AIM: The aim of this study is to demonstrate the added value of three-dimensional (3D) reconstruction models and artificial intelligence for preoperative planning in complex perianal Crohn's disease. MRI is the gold standard for diagnosis of complex perianal fistulas and abscess due to its high sensitivity, but it lacks high specificity values. This creates the need for better diagnostic models such as 3D image processing and reconstruction (3D-IPR) with artificial intelligence (AI) algorithms. METHOD: This is a prospective study evaluating the utility of 3D reconstruction models from MRI in four patients with perineal Crohn's disease (pCD). RESULTS: Four pCD patients had 3D reconstruction models made from pelvic MRI. This provided a more visual representation of perianal disease and made possible location of the internal fistula orifice, seton placement in fistula tracts and abscess drainage. CONCLUSION: Three-dimensional reconstruction in CD-associated complex perianal fistulas can facilitate disease interpretation, anatomy and surgical strategy, potentially improving preoperative planning as well as intraoperative assistance. This could probably result in better surgical outcomes to control perianal sepsis and reduce the number of surgical procedures required in these patients.

Long term outcome of multidisciplinary management of urethro-rectal fistula after urologic surgery.

Urethro-rectal fistula (URF) is a rare but serious condition whose treatment is poorly codified. This study aims to evaluate the short and long-term results of multidisciplinary management. MATERIAL AND METHODS: We retrospectively collected the records of patients with URF operated on at the University Hospital of Tours between January 1, 2000 and January 1, 2020. Short-term and long-term results according to management are reported. RESULTS: The study included 20 patients. As an initial gesture, 11 patients underwent bladder catheterization and colostomy, seven underwent bladder catheterization alone, one underwent graciloplasty, and one, a York Mason procedure. The success rate of initial conservative management was only 5% (1/20). As a secondary or tertiary intervention, ten patients underwent a York Mason procedure and nine underwent graciloplasty. At the end of the study period, with a median follow-up of 50 months, 19 had been effectively treated for URF, 16 were able to have colostomy closure with restoration of digestive continuity while four had a permanent stoma. One patient had anal incontinence, 14% had major stress urinary incontinence. CONCLUSION: Multidisciplinary care remains a cornerstone of the treatment of URF because iterative surgeries may be required, with an overall success rate of up to 95% at the end of follow-up.

Incidence of anal fistula after pyogenic perianal abscess drainage in Kingdom of Bahrain.

PURPOSE: Perianal fistula is one of the most common anorectal diseases in adult patients, especially men. A relationship between pyogenic perianal abscess and fistula formation is established in multiple domains. This is the first exploration of such association among patients in the country as no related study has been published in Bahrain. We expect this study to be a foundation for future protocols and evidence-based practice. METHODS: A retrospective study was conducted in Salmaniya Medical Complex of Bahrain. A total of 109 patients with a diagnosis of anal abscess were included between 2015 and 2018. Data were collected from the electronic files database used in Salmaniya Medical Complex (iSeha) as well as phone calls to the patients. Collected data were analyzed using statistical software. RESULTS: The most predominant presentation of perianal abscess was pain. Over 50% of abscesses were classified as perianal (56.9%) and among those, left-sided abscesses were more common, followed by right-, posterior-, and anterior-sited, respectively. No recurrence of abscess was recorded among 80% of patients. A fistula developed following abscess drainage in 33.9% of patients. Most fistulas (37.8%) were diagnosed within 6 months or less from abscess drainage. Posterior fistulas were the most common, followed by anterior and left-sided fistulas. CONCLUSION: The incidence of anal fistula in Bahrain after perianal abscess was 33.9%. Most of the patients who developed a fistula following pyogenic abscess drainage were males and above the age of 40 years. The most common site for fistula was posterior.

Garg scoring system to predict long-term healing in cryptoglandular anal fistulas: a prospective validation study.

Purpose: Complex anal fistulas can recur after clinical healing, even after a long interval which leads to significant anxiety. Also, ascertaining the efficacy of any new treatment procedure becomes difficult and takes several years. We prospectively analyzed the validity of Garg scoring system (GSS) to predict long-term fistula healing. Methods: In patients operated for cryptoglandular anal fistulas, preoperative magnetic resonance imaging (MRI) and postoperative MRI was done at 3 months to assess fistula healing. Scores as per the GSS were calculated for each patient at 3 months postoperatively and correlated with long-term healing to check the accuracy of the scoring system. Results: Fifty-seven patients were enrolled, but 50 were finally included (7 were excluded). These 50 patients (age, 41.2± 12.4 years; 46 males) were followed up for 12 to 20 months (median, 17 months). Forty-seven patients (94.0%) had complex fistulas, 28 (56.0%) had recurrent fistulas, 48 (96.0%) had multiple tracts, 20 (40.0%) had horseshoe tracts, 15 (30.0%) had associated abscesses, 5 (10.0%) were suprasphincteric, and 8 (16.0%) were supralevator fistulas. The GSS could accurately predict long-term healing (specificity and high positive predictive value, 31 of 31 [100%]) but was not very accurate in predicting non-healing (negative predictive value, 15 of 19 [78.9%]). The sensitivity in predicting healing was 31 of 35 (88.6%). Conclusion: GSS accurately predicts long-term fistula with a high positive predictive value (100%) but is less accurate in predicting non-healing. This scoring system can help allay anxiety in patients and facilitate the early validation of innovative procedures for anal fistulas.

Negative Pressure Wound Therapy for the Treatment of Fournier's Gangrene: A Rare Case with Rectal Fistula and Systematic Review of the Literature.

Fournier's gangrene (FG) is a Necrotizing Soft Tissue Infection (NSTI) of the perineal region characterized by high morbidity and mortality even if appropriately treated. The main treatment strategies are surgical debridement, broad-spectrum antibiotics, hyperbaric oxygen therapy, NPWT (Negative Pressure Wound Therapy), and plastic surgery reconstruction. We present the case of a 50-year-old woman with an NSTI of the abdomen, pelvis, and perineal region associated with a rectal fistula referred to our department. After surgical debridement and a diverting blow-out colostomy, an NPWT system composed of two sponges connected by a bridge through a rectal fistula was performed. Our target was to obtain healing in a lateral-to-medial direction instead of depth-to-surface to prevent the enlargement of the rectal fistula, promoting granulation tissue growth towards the rectum. This eso-endo-NPWT technique allowed for the primary suture of the perineal wounds bilaterally, simultaneously treating the rectal fistula and the perineum lesions. A systematic review of the literature underlines the spreading of NPWT and its effects.

A Comparison of Different Surgical Treatments for Complex Anal Fistula: A Systematic Review.

Fistula-in-ano is a common proctological condition that primarily affects younger people and leads to chronic morbidity. An anal fistula is divided into simple and complex fistulas. A complex fistula is a challenging problem due to higher recurrence rates and incontinence associated with surgery. Many new methods have been developed for the closure of complex fistula-in-ano, but there is no single best method. The aim of this study is to identify a superior surgical technique for treating complex/high cryptoglandular perianal fistulas (HCPFs). A literature search was done using PubMed and Google Scholar for the period of 2012-2021. Articles that contain surgical treatment for complex anal fistula in the English language published in the last 10 years were included. The types of studies included were randomized controlled trials (RCTs), meta-analyses, systematic reviews, cohort studies, and traditional reviews. Articles excluded were those done more than 10 years ago, in other languages, and containing simple fistula management only. Nine studies were included in the review; a systematic review and meta-analysis concluded that no single method is effective. The ligation of the intersphincteric fistula tract (LIFT) procedure seems to be a promising and effective technique as it has a low rate of fecal incontinence as compared to other methods. Biological techniques give variable success rates so does fistula plug (FP). Mucosal advancement flap (MAF) and rerouting seton give good results according to one study. Fistula plug gives variable results and is not a preferred method. Ligation of the intersphincteric fistula tract (LIFT) seems to be a promising new technique for complex anal fistulas, but the data available is not enough to determine the best method. More randomized trials are required to compare traditional techniques and emerging new biological methods to see the best technique available.

Patient-Reported Outcomes Measures in Perianal Fistulizing Crohn's Disease.

Perianal fistulizing Crohn's disease (PFCD) is a disabling complication of Crohn's disease (CD) that can significantly impact on patients' quality of life (QoL) and often requires multidisciplinary care. Clinical trials assessing the efficacy of medical and surgical interventions for fistulas usually evaluate outcomes such as closure of fistula tracts or radiologic healing. However, these traditional outcome assessments fail in capturing the impact of the disease from patients' perspectives. In this context, regulatory authorities have increasingly encouraged the inclusion of validated patient-reported outcomes (PRO) that assess disease activity and reveal how a patient functions and feels. This recent trend towards patient-centered care aims to ensure that improvements in efficacy outcomes are accompanied by meaningful benefits to patients. The aim of this review is to discuss currently available PRO measures (PROMS) for the assessment of PFCD to provide to physicians appropriate tools aiming to optimize patient care and disseminate the use of these instruments in clinical practice.

A case of microsatellite instability-high clinically advanced castration-resistant prostate cancer showing a remarkable response to pembrolizumab sustained over at least 18 months.

Defective DNA mismatch repair genes can lead to microsatellite instability (MSI)-high status in prostate cancer (PC). Accumulation of replication errors in DNA leads to the production of abundant neoantigens, which could be targets for immune checkpoint inhibitors (CPIs). However, the incidence of MSI-high PC is low, and not all patients show a satisfactory therapeutic response to CPIs. Here, we present the case of a patient with MSI-high castration-resistant PC who showed a remarkable and durable response to pembrolizumab. The patient was resistant to abiraterone, docetaxel, and cabazitaxel and was suffering from multiple tumor-associated or treatment-related complications, such as urinary tract infection, infective endocarditis, and uncontrollable prostatic hemorrhage. Soon after the start of pembrolizumab therapy, the patient showed a dramatic decrease in prostate-specific antigen from 35.67 ng/mL to an undetectable level and a remarkable reduction in the size of a massive prostate mass and lymph node metastases, with an absence of treatment-related complications. Specimens from the transurethral resection of prostate cancer during cabazitaxel treatment for control of prostate bleeding and also that from the prostate biopsy at initial diagnosis revealed MSI-high status. Immunohistochemistry showed loss of MSH2 and MSH6, and whole-exome sequencing revealed an approximate tumor mutation burden of 61 mutations/Mb as well as biallelic loss of MSH2 Pembrolizumab could show a significant effect even in a heavily treated patient with MSI-high advanced PC. Accumulation of detailed clinical and genomic information of cases of MSI-high PC treated with pembrolizumab is necessary for optimal patient selection.