Surgical Anatomy of the Rectovaginal Space: Does a Standalone Rectovaginal Septum or Denonvilliers Fascia Exist in Women?

BACKGROUND: Below the anterior peritoneal reflection, the anterior rectal wall and mesorectum are separated from the posterior vaginal wall by a virtual rectovaginal space. In this space, the description of a specific and independent rectovaginal septum as a female counterpart of Denonvilliers fascia has been the subject of debate over the years. OBJECTIVE: The aim of this study is to perform an accurate anatomical study of the rectovaginal area in a cadaveric simulation model of total mesorectal excision to evaluate the possible structures and the dissection planes contained within the rectovaginal space. DESIGN AND SETTING: This is a cadaveric study performed at the University of Valencia. PATIENTS: The pelvises of 25 formalin-preserved female cadavers were dissected. All the included specimens were sectioned in a midsagittal plane, at the level of the middle axis of the anal canal. MAIN OUTCOME MEASURES: Careful and detailed dissection was performed to visualize the anatomical structures and potential dissection planes during anterior mesorectal dissection in cadavers. Histological sections were made of the posterior vaginal wall. RESULTS: The rectovaginal space contains loose areolar tissue that allows an easy dissection plane distally. A distinct and independent rectovaginal fascia or septum is not present. The existence of 3 layers fused together in the posterior vaginal wall can be identified more or less precisely because of their different coloration. The histological study confirms this macroscopic arrangement of the posterior vaginal wall in 3 layers: the mucosa, the muscular, and the adventitia. An independent rectovaginal septum can be generated only with a splitting of the adventitia. LIMITATIONS: The cadaveric pelvic specimens of the oldest donors might have had age-related degeneration. CONCLUSIONS: The present anatomical study has shown only a plane of loose areolar tissue between the rectal and vaginal wall. We can conclude that there is no independent fascia or septum in the rectovaginal space. See Video Abstract at http://links.lww.com/DCR/B456. ANATOMÍA QUIRÚRGICA DEL ESPACIO RECTOVAGINAL: ¿EXISTE UN TABIQUE RECTOVAGINAL INDEPENDIENTE O UNA FASCIA DE DENONVILLIERS EN LAS MUJERES: Debajo del reflejo peritoneal anterior, la pared rectal anterior y el mesorrecto están separados de la pared vaginal posterior por un espacio rectovaginal virtual. En este espacio, la descripción de un tabique rectovaginal independiente específico como contraparte femenina de la fascia de Denonvilliers ha sido objeto de debate a lo largo de los años.Realizar un estudio anatómico preciso del área rectovaginal en un modelo de simulación cadavérica de escisión mesorrectal total, con el fin de evaluar las posibles estructuras y los planos de disección contenidos en el espacio rectovaginal.estudio cadavérico realizado en la Universidad de Valencia.Se disecaron las pelvis de 25 cadáveres femeninos conservados en formalina. Todas las muestras incluidas fueron seccionadas en un plano medio sagital, a la altura del eje medio del canal anal.Se llevó a cabo una disección cuidadosa y detallada para visualizar las estructuras anatómicas y los posibles planos de disección durante la disección mesorrectal anterior en cadáveres. Se realizaron cortes histológicos de la pared vaginal posterior.El espacio rectovaginal contiene tejido areolar laxo que permite un plano de disección fácil distalmente. No hay fascia o tabique rectovaginal distinto e independiente. La existencia de tres capas fusionadas en la pared vaginal posterior puede identificarse con mayor o menor precisión debido a su diferente coloración. El estudio histológico confirma esta disposición macroscópica de la pared vaginal posterior en tres capas: la mucosa, la muscular y la adventicia. Un tabique rectovaginal independiente solo se puede generar con una división de la adventicia.Las muestras pélvicas de cadáveres de los donantes más antiguos pueden haber tenido degeneración relacionada con la edad.El estudio anatómico actual solo ha mostrado un plano de tejido areolar laxo entre la pared rectal y vaginal. Podemos concluir que no hay fascia o tabique independiente en el espacio rectovaginal. Consulte Video Resumen en http://links.lww.com/DCR/B456. (Traducción-Dr. Adrian Ortega).

Impact of a diverting stoma in an enhanced recovery programme for rectal cancer.

PURPOSE: The association of a loop ileostomy decreases the severity of complications after rectal surgery but can increase the postoperative stay. The aim of this study is to investigate if a diverting ileostomy influences the postoperative outcomes in a series of patients included in a multimodal rehabilitation program (MMRP). METHODS: We analyzed a series of 104 patients that underwent elective surgery with primary anastomosis for rectal adenocarcinoma using a MMRP: 66 men and 38 women, with a median age of 64 (IQR: 55-75) years. Group A included patients with an associated loop ileostomy, and Group B, those without a protective stoma. RESULTS: Group A = 58, group B = 46 patients without differences in age, ASA, BMI and other risk factors, nor in the surgical approach (laparoscopic in 34%), although there were more neoadjuvant treatments in group A: 77.5 vs. 36.9%; P=.001. In group A, the most common operation was total mesorectal excision (96%) and in the B, a subtotal mesorectal excision (90%). There were no differences in postoperative complications (Group A 34.4 vs. group B28.2%; P=.322), anastomotic leaks (8.3 vs. 10.8%; P=.475), or postoperative ileus (20.7 vs. 10.9%; P=.140), neither in postoperative stay (7.9 vs. 6.9 days; P= .058, readmissions (7 vs. 13.6%; P= .22), or postoperative stay, including readmissions (8.4 vs. 9.1 days; P= .49). CONCLUSIONS: The association of a loop ileostomy does not extend the length of stay nor increases the rate of complications in patients that underwent a rectal resection with anastomosis included in a MMRP.

Anatomical sphincteroplasty as a surgical treatment for faecal incontinence: proposal for a global anatomical reconstructive surgical procedure and results from a case series.

The aim of this study is to describe the technical details and clinical and functional results of anatomical sphincteroplasty as a global reconstructive surgery for the treatment of faecal incontinence caused by anal sphincter lesions. This was a prospective, longitudinal study that included patients who underwent the anatomical sphincteroplasty procedure described here to treat complete sphincter damage. We have described the different technical steps in detail. We evaluated the intraoperative and postoperative complications rate, Cleveland Clinic Score (CCS), a modification of the CCS that included soiling (mCCS), the Faecal Incontinence Quality of Life Scale (FIQLS), and patient satisfaction. An endoanal ultrasound and anorectal manometric study were performed in all the patients. Forty-four patients were included with a mean of 40.5 months follow-up. The CCS reduced from 15 to 3.3 points and the mCCS from 18.5 to 4.5 points over the study period; p < 0.001. Excellent or good results were achieved in 93% of cases. Endoanal ultrasounds showed a good sphincter repair in 66% of the cases. Anorectal manometry showed an increase in the mean maximal resting pressure from 27.6 mmHg to 41.7 mmHg and of the maximal squeeze pressure from 57.9 to 93 mmHg (p < 0.001) with respect to the preoperative values. Anatomical sphincteroplasty is a surgical proposal for the global anatomical reconstruction of anal sphincter lesions, even in cases of very severe damage. The procedure is safe and produced excellent clinical and functional results after a medium-term follow-up.

[Treatment of complex cryptoglandular anal fistulas. Does it still require an experienced surgeon?]. / Tratamiento de las fístulas de ano complejas de causa criptoglandular. ¿Aún se requiere un cirujano con experiencia?

There is still controversy on the management of complex cryptoglandular fistulas, even after employing the newest, theoretically simple, techniques. A critical review of the literature was performed, in order to clarify the role of the surgeon, where the precarious balance between eradicating sepsis and maintaining anorectal influences the choice. Techniques, such as fistulotomy, immediate sphincter repair or ligature of the inter-sphincter trajectory, are discussed. The new sphincter preserving techniques, such as sealing, use of plugs and cell therapy are also analysed. However, with a few exceptions, the scientific evidence is low or zero, due to the lack of clinical trials and to the large variation in the presentations and technical details that could influence the results. For this reason, experience in treating complex cryptoglandular fistulas is still essential.

[Analysis of experience in the use of dynamic pelvic magnetic resonance imaging in the assessment of obstructive defaecation syndrome]. / Análisis de nuestra experiencia mediante el uso de resonancia magnética dinámica pelviana en la evaluación del síndrome de defecación obstructiva.

INTRODUCTION: The aetiological diagnosis of obstructive defaecation syndrome (ODS) requires, among others, imaging tests. The purpose of this study is to descriptively analyse and compare the findings of dynamic pelvic magnetic resonance imaging (DPMRI) with the clinical examinations in patients with ODS. MATERIAL AND METHODS: A prospective comparative study was made between the physical examination and the DPMRI, with a descriptive analysis of the results. A total of 30 patients were included (2 males and 28 females), with a median age of 60 (range 23-76) years, with symptoms of ODS. An anamnesis and detailed physical examination and a DPMRI were performed on all of them. Functional (anismus) and morphological changes (rectocele, enterocele, intussusception, etc.), were analysed. RESULTS: The physical examination did not detect anomalies in 6 (20%) patients. A rectocele was diagnosed in 21 (70%) of the cases, and 2 (6.7%) a rectal mucosal prolapse. The DPMRI showed evidence of pelvic floor laxity in 22 (73.3%) cases, an enterocele in 4 (13.3%), a sigmoidocele in 2 (6.7%), intussusception in 8 (26.7%), rectal mucosal prolapse in 4 (13.3%), anismus in 3 (10%), and a cystocele in 4 (13.3%). The rectocele was the most frequent diagnosis, being given in 26 (86.6%) patients. CONCLUSIONS: Magnetic resonance imaging provides an overall pelvic assessment with good definition of the tissues, and does not use ionising radiation, is well tolerated, and provides us with complementary information to arrive at the diagnosis, and establish the best treatment for ODS. Larger studies comparing videodefaecography (VD), currently considered the Gold Standard technique, are needed to be able to demonstrate whether it is superior or not to DPMRI.

Anatomic sphincteroplasty with combined reconstruction of internal and external anal muscles in the anal incontinence surgical treatment.

Several groups studying the results of the classic sphincteroplasty show improvement of 75% of patients treated in a short-term follow-up, with a worsening of this data in the long-term follow-up down to an improvement of 50% of the patients. Some other groups published more optimistic results, showing an 80% success rate without any deterioration of the technique over time after introducing a separate repair of the internal and external muscles. We think that the introduction of some modifications in the classic technique, named "Anatomic sphincteroplasty with combined reconstruction of external and internal anal sphincter muscles" may obtain very good clinical and anorectal manometric results both in a short and mid-term follow-up. In addition, increasing the pressive length in the anal canal may contribute to maintain more stable results over time.

Navigating surgical anatomy of the Denonvilliers' fascia and dissection planes of the anterior mesorectum with a cadaveric simulation model.

Anterior dissection of the rectum in the male pelvis represents one of the most complex phases of total meso-rectal excision. However, the possible existence of different anatomical planes is controversial and the exact anatomical topography of Denonvilliers' fascia is still debated. The aim of the study is to accurately define in a cadaveric simulation model the existence and boundaries of Denonvilliers' fascia, identifying the anatomical planes suitable for surgical dissection. The pelvises of 31 formalin-preserved male cadavers were dissected. Careful and detailed dissection was carried out to visualize the anatomical structures and the potential dissection planes, simulating an anterior meso-rectum dissection. Denonvilliers' fascia was identified in 100% of the pelvises, as a single-layer fascia that originates from the peritoneal reflection and descends until its firm adhesion to the prostate capsule. The fascia divides the space providing an anterior and a posterior plane. Anteriorly to the fascia, during the caudal dissection, its firm adhesion to the prostate capsule forces to section it sharply. The cadaveric simulation model allowed an accurate description of Denonvilliers' fascia, defining several planes for anterior dissection of the meso-rectum.

Validation of pelvic magnetic resonance imaging as the method of choice to determine the distance to the anal margin in rectal cancer.

INTRODUCTION: Distance from anal verge of rectal tumours and their anatomical relationships contribute to determine the multidisciplinary therapeutic strategy based on the combination of radio-chemotherapy and radical surgery. Our aims are to investigate which is the most accurate method for the preoperative measuring of the distance from the anal verge in rectal tumours and if the pelvic MRI can substitute the classical instrumental methods. METHODS: Prospective study of diagnostic precision between flexible colonoscopy (FC), preoperative rigid rectosigmoidoscopy (pRR) and pelvic MRI in patients scheduled to radical surgery. Rigid intraoperative rectoscopy (iRR) was considered the reference test. The correlations between the different techniques and their determination coefficient as well as the intraclass correlation coefficient and the degree of agreement between the different tests were analyzed. RESULTS: 96 patients (65% males), mean age (SD): 68 (14.1) years were included. 72% received neoadjuvant treatment. The mean distance to the anal margin measured by FC = 103.5 mm, was significantly greater than others, which had similar values: pRR = 81.1; MRI = 77.4; iRR = 82.9 mm (P < .001). A significant intraclass correlation was observed and there was high agreement between all pre- and intraoperative measurements except for the performed by FC, which overestimated the results. MRI provided more individualized and accurate information. CONCLUSIONS: There is variability between the measurement methods, being colonoscopy the least reliable. MRI offers objective, comparable, accurate and individualized values that can replace those obtained by pRR for tumours of any location in the rectum.

[Selective intestinal preparation in a multimodal rehabilitation program. Influence on preoperative comfort and the results after colorectal surgery]. / Preparación intestinal selectiva en un programa de rehabilitación multimodal. Influencia en el confort preoperatorio y resultados tras cirugía colorrectal.

INTRODUCTION: Despite there being no evidence of the advantages of its use, mechanical bowel preparation (MBP) continues to be routine in colorectal surgery. Our objective is to analyse the impact of its selective use, as regards patient comfort and results, comparing a perioperative multimodal rehabilitation program (MMRH) with conventional care (CC). MATERIAL AND METHODS: A prospective study of 108 patients proposed for elective surgery, assigned consecutively 2:1 to an MMRH protocol which only included MBP in rectal surgery with low anastomosis, or to CC in whom MBP was used except in right colon surgery. We also studied two Groups (A and B) with and without the use of MBP. Their tolerance, results and postoperative recovery variables were analysed. RESULTS: Thirty-nine patients were included in Group A, and 69 in Group B. A MMRH protocol was used in another 69 patients. The Group A patients had more abdominal pain, anal discomfort, nausea and thirst, but there were no differences as regards, death, overall or local complications, whilst there was less complications, suture failures and death in the MMRH when compared with CC Group (P<.05). There were no advantages observed in the use of MBP as regards the start of bowel movements, tolerance to diet or hospital stay, but these parameters were favourable to the MMRH when compared with CC Group. CONCLUSIONS: The restriction of MBP is safe, and associated with an MMRH program, contributes to a faster and more comfortable recovery, without increasing complications.

[Accreditation and dedication in coloproctology is associated with good perioperative care]. / La acreditación y dedicación en coloproctología se asocian a buenos cuidados perioperatorios.

UNLABELLED: Complex data analysis methods require optimisation techniques such as evolutionary algorithms in order to generate reliable results. The objective of this study is to analyse the relationships of particular perioperative care in colorectal surgery (CRS) with surgeon epidemiological data, performing partition grouping to look for significant relationships. METHODS: Data were used from a survey of members of Spanish coloproctology associations on perioperative care in colorectal surgery, and analysing the responses associated with mechanical bowel preparation (MBP), nasogastric intubation (NGI), drainages (D), and early feeding (EF), over the existing scientific evidence (SE) which shows that the first ones are unnecessary and the importance of the last one. We applied a variant of particle swarm optimization (PSO), to group data conglomerates, optimising variables with statistical grouping criteria. RESULTS: A total of 130 surveys were analysed, finding 2 clear groups which included 21.5% and 78.5% of the sample, respectively. Sixty eight per cent of the surgeons in Group A belonged to the European Board in Coloproctology, compared to none in Group B, and the former performed 80% of the coloproctology activity, compared to 60% of the rest. A responded homogeneously to questions on MBP, NGI, D and EF, those of group A following the SE, while the others did it randomly and without following it. Age, work position or academic range were not significant in the grouping. CONCLUSIONS: The evolutionary algorithm was shown to be able to identify groups according to the use of perioperative care in CRS. Accreditation and dedication was associated with behaviour based on the SE.

Validation of pelvic magnetic resonance imaging as the method of choice to determine the distance to the anal margin in rectal cancer. / Validación de la resonancia magnética pélvica como método de elección para determinar la distancia al margen anal en el cáncer de recto.

INTRODUCTION: Distance from anal verge of rectal tumors and their anatomical relationships contribute to determine the multidisciplinary therapeutic strategy based on the combination of radio-chemotherapy and radical surgery. Our aims are to investigate which is the most accurate method for the preoperative measuring of the distance from the anal verge in rectal tumors and if the pelvic MRI can substitute the classical instrumental methods. METHODS: Prospective study of diagnostic precision between flexible colonoscopy (FC), preoperative rigid rectosigmoidoscopy (pRR) and pelvic MRI in patients scheduled to radical surgery. Rigid intraoperative rectoscopy (iRR) was considered the reference test. The correlations between the different techniques and their determination coefficient as well as the intraclass correlation coefficient and the degree of agreement between the different tests were analyzed. RESULTS: 96 patients (65% males), mean age (SD): 68 (14.1) years were included. 72% received neoadjuvant treatment. The mean distance to the anal margin measured by FC=103.5mm, was significantly greater than others, which had similar values: pRR=81.1; MRI=77.4; iRR=82.9mm (P<.001). A significant intraclass correlation was observed and there was high agreement between all pre- and intraoperative measurements except for the performed by FC, which overestimated the results. MRI provided more individualized and accurate information. CONCLUSIONS: There is variability between the measurement methods, being colonoscopy the least reliable. MRI offers objective, comparable, accurate and individualized values that can replace those obtained by pRR for tumors of any location in the rectum.

[Self-evaluation of a clinical pathway to improve the results of rectal cancer]. / Autoevaluación de una vía clínica para mejora del proceso quirúrgico carcinoma de recto.

OBJECTIVES: To analyse whether the self-evaluation of a clinical pathway improves the results of rectal cancer (RC) treatment. PATIENTS AND METHOD: Patients operated on for RC were divided into 3 groups according to biannual modifications of a clinical pathway analysing several indicators. RESULTS: 166 patients: Group A: 2002-3 n=50, B: 2004-5 n=53 and C: 2006-7 n=63, without any differences in age, gender or comorbidity. Preoperative study improved with the introduction of CT scan: 76% in Group C vs. 6% in Group A (P<0.001). All Group C tumours were staged using MR, rectal ultrasound or both, compared to 84% in Group A (P<0.001). The rate of abdominal-perineal resections was reduced from 42% (Group A) to 17% (Group C); (P=0.007) and about 48% of surgeons in Group A vs. 94% in the C had a specific activity in coloproctology (P<0.001). The average lymph node count was: Group A=6.2+/-4.5 vs. 13+/-6.5 in the C and circumferential margin analysis was reported in 24% of Group A vs. 76% in Group C (P<0.001). Parameters such as perioperative blood transfusion, ICU admission, use of nasogastric tube, early feeding or epidural analgesia also improved progressively. Operative mortality decreased non-significantly to 4.7% and anastomotic leaks from 24% to 9.5% with a reduction in postoperative stay from 15 to 11 days during the period analysed (P=0.029). CONCLUSIONS: Several indicators have significantly improved in a relatively short period of time due to self-evaluations of the process.

Changes in anorectal morphologic and functional parameters after fistula-in-ano surgery.

PURPOSE: This study aimed to analyze changes in anal continence and morphologic and functional anorectal variables after fistula-in-ano surgery in a patient series with a high rate of complex fistulas. METHODS: One hundred twenty patients with a mean age of 46.9 (standard deviation, 12.8) years were prospectively analyzed by evaluating anal continence, results of endoanal ultrasound examination and anorectal manometry, and pudendal nerve terminal motor latency before and after fistula-in-ano surgery. RESULTS: Forty-three patients (35.8%) were referred for recurrent fistulas; fistulas in and 70 (58.3%) were considered complex. Preoperatively, 17 patients (14.2%) presented with impaired continence. At follow-up, 59 patients (49.2%) had some degree of incontinence (P < 0.001). The techniques that most affected continence were rectal advancement flap and fistulotomy. Endoanal ultrasound examination showed that the number of patients with internal anal sphincter defects increased from 37 (30.8%) to 78 (74.3%) after surgery (P < 0.001); those with external anal sphincter defects increased from 17 (15.9%) to 34 (32.4%) (P < 0.001). Techniques most associated with increases in internal anal sphincter defects were fistulotomy (P < 0.003) and rectal advancement flap (P < 0.004). Anal manometry showed significant decreases in maximal resting pressure and maximum squeeze pressure in patients with previous incontinence (P < 0.001), and in those with internal anal sphincter defects (P < 0.001). Fistulotomy decreased both resting pressure (P < 0.004) and squeeze pressure (P < 0.007), whereas rectal advancement flap significantly reduced only resting pressure. Pudendal nerve latency did not differentiate continent and incontinent patients, and showed no postoperative change. CONCLUSIONS: Anal continence is significantly affected after fistula-in-ano surgery, mainly because of sphincteric lesions that affect anal canal pressures and that can be imaged with endoanal ultrasound. It is important to preoperatively recognize sphincter defects to allow adequate surgical treatment.

Acute diverticulitis and surgical treatment.

Diverticulitis is a common condition in industrialized countries and an important cause of hospital admissions. Its growing trend is a challenge for the surgeons who perform emergency surgery, because approximately 15-25% of the patients will require surgery, being the surgical management of complicated acute diverticulitis controversial. The past decade has seen a paradigm shift in the treatment of sigmoid diverticulitis based on new epidemiological studies and refinement of surgical techniques that has produced a reassessment of our guidelines. CT imaging and sepsis scores allows to stratify the patients and better define the therapeutic strategies in each case. Special considerations must also be made for patients with a high surgical risk, such as immunosuppressed ones. The recommendations to perform surgery after two episodes of uncomplicated diverticulitis have been re-evaluated and the belief that new episodes may be complicated and associated with high morbidity and mortality has been rejected, since the clinical manifestations of this disease are usually defined by the first attack. In complicated cases, more patients can be treated with resection and primary anastomosis with or without an associated stoma, whose reversal rate is much higher than that of a Hartmann's procedure. Likewise, laparoscopic surgery performing a peritoneal lavage and drainage without associated resection may have an increasing role in the management of these patients, although with controversial results, having become laparoscopic colon resection the approach of choice for the treatment of this pathology in elective settings.

Treatment algorithm for anal fissure. Consensus document of the Spanish Association of Coloproctology and the Coloproctology Division of the Spanish Association of Surgeons. / Tratamiento de la fisura anal: algoritmo de actuación. Documento de consenso de la Asociación Española de Coloproctología y la Sección de Coloproctología de la Asociación Española de Cirujanos.

The Spanish Association of Coloproctology and the Coloproctology Division of the Spanish Association of Surgeons propose this consensus document with a treatment algorithm for anal fissure that could be used for decision making. Non-surgical therapy and surgical treatment of anal fissure are explained, and the recommended algorithm is provided. The methodology used was: creation of a group of experts; search in PubMed, MEDLINE and the Cochrane Library for publications from the last 10 years about anal fissure; presentation at the 21st National Meeting of the Spanish Association of Coloproctology Foundation 2017 with voting for/against each conclusion by the attendees and review by the scientific committee of the Spanish Association of Coloproctology.

Stoma reversal after surgery for complicated acute diverticulitis: A multicentre retrospective study. / Reconstrucción de la continuidad digestiva tras cirugía de la diverticulitis aguda complicada. Estudio retrospectivo multicéntrico.

INTRODUCTION THE AIM: was to analyse the stoma reversal rate after surgery for complicated acute diverticulitis (CAD), and more specifically the end-stoma-reversal, as well as the delay, feasibility, complications and risk factors for stoma maintenance. METHODS: A multicentre retrospective study of patients who had undergone urgent surgery for CAD with stoma formation in ten hospitals during a period of 6 years. The frequency of reversal over time and the factors affecting the decision for reversal were analysed. RESULTS: Out of 385 patients operated for CAD, 312 underwent stoma creation: 292 end colostomies and 20 diverting stomas. During follow-up, stoma reversal surgery was performed in 161 patients (51.6%) after a median of 9 months. The main causes for not performing stoma reversal were comorbidities and the death of the patient. Advanced age was an adverse factor in the multivariate analysis, and the actuarial rate of reversal was higher in men and in patients with no previous Hartmann's operation. Stoma reversal surgery was completed in all but one patient, and a loop ileostomy was associated in four. Morbidity and mortality rates were 35.7% and 1.9%, respectively. A total of 8.4% of patients underwent re-operation, and 6% experienced an anastomotic leak. Twelve patients remained with a stoma after the attempted reconstruction surgery. CONCLUSIONS: Surgery for CAD is frequently associated with an end stoma, which will ultimately not be reversed in almost 50% of patients. Moreover, reversal surgery is frequently delayed and is associated with significant morbidity and mortality.