Neonatal Intestinal Segmental Volvulus: What Are the Differences with Midgut Volvulus?

OBJECTIVE: Intestinal volvulus in the neonate is a surgical emergency caused by either midgut volvulus (MV) with intestinal malrotation or less commonly, by segmental volvulus (SV) without intestinal malrotation. The aim of our study was to investigate if MV and SV can be differentiated by clinical course, intraoperative findings, and postoperative outcomes. METHODS: Using a defined search strategy, two investigators independently identified all studies comparing MV and SV in neonates. PRISMA guidelines were followed, and a meta-analysis was performed using RevMan 5.3. RESULTS: Of 1,026 abstracts screened, 104 full-text articles were analyzed, and 3 comparative studies were selected (112 patients). There were no differences in gestational age (37 vs. 36 weeks), birth weight (2,989 vs. 2,712 g), and age at presentation (6.9 vs. 3.8 days). SV was more commonly associated with abnormal findings on fetal ultrasound (US; 65 vs. 11.6%; p < 0.00001). Preoperatively, SV was more commonly associated with abdominal distension (32 vs. 77%; p < 0.05), whereas MV with a whirlpool sign on ultrasound (57 vs. 3%; p < 0.01). Bilious vomiting had similar incidence in both (88 ± 4% vs. 50 ± 5%). Intraoperatively, SV had a higher incidence of intestinal atresia (2 vs. 19%; p < 0.05) and need for bowel resection (13 vs. 91%; p < 0.00001). There were no differences in postoperative complications (13% MV vs. 14% SV), short bowel syndrome (15% MV vs. 0% SV; data available only from one study), and mortality (12% MV vs. 2% SV). CONCLUSION: Our study highlights the paucity of studies on SV in neonates. Nonetheless, our meta-analysis clearly indicates that SV is an entity on its own with distinct clinical features and intraoperative findings that are different from MV. SV should be considered as one of the differential diagnoses in all term and preterm babies with bilious vomiting after MV was ruled out-especially if abnormal fetal US and abdominal distension is present.

Analysis of abdominal adhesion using the ileostomy model.

Abdominal adhesion occurs commonly in clinical practice, causing unfavorable symptoms and readmission. The ileostomy operation is a common surgical procedure and we utilized this model to evaluate abdominal adhesion. Adhesion grade score was calculated in 35 patients (Cohort 1) and subjected to correlation and receiver operating characteristic analysis. Then 98 consecutive patients (Cohort 2) who underwent ileostomy and ileostomy closure were included into a retrospective study. Logistic regression analysis was performed, and the risk of small bowel obstruction was also assessed. The time of ileostomy closure correlated with adhesion grade score in Cohort 1, justifying its use as an indicator of abdominal adhesion. All patients in Cohort 2 were then divided into the high- and low-adhesion group. A multi-variable logistic regression analysis indicated that type of surgery and peritoneum suture during ileostomy were significant factors affecting the risk of abdominal adhesion. Abdominal adhesion had the trend to prolong the length of stay postoperatively without increasing the risk of bowel obstruction. Nine patients suffered bowel obstruction, and age older than 65 significantly increased the risk. We proposed the ileostomy procedure to be a model of abdominal adhesion, and the operative time of ileostomy closure could be used as an alternative of adhesion score. Type of surgery and peritoneum suture may be risk factors of abdominal adhesion. Older age increased the risk of small bowel obstruction after ileostomy surgery.

Gastric duplication cyst of a bifid pancreas: cause of recurrent vomiting.

An infant girl first presented with recurrent episodes of non-bilious vomiting, having had five hospitalisations over the following months because of dehydration. Laboratory data showed no inflammatory response, normal pancreatic amylase, but increased lipase levels (between 67 and 425 U/L). Several abdominal ultrasound studies suggested an intestinal duplication cyst on left hypochondrium and, later, a dilated and irregular pancreatic duct. CT showed a bifid tailed pancreas and a change in the cyst's characteristics. A communication with the pancreatic duct was hypothesised, which was confirmed on MR cholangiopancreatography. On laparoscopic surgery, the cyst was confirmed to be at the end of the caudal side of the pancreatic bifid tail, having no communication with the stomach. Cystectomy with partial pancreatectomy was performed with pathological findings confirming a gastric duplication cyst originating from the pancreatic bifid tail. At latest follow-up, 4 months after surgery, she remains asymptomatic.

Type II Congenital Pyloric Atresia with Desquamative Enteropathy Diagnosed Postoperatively: A Case Report.

Congenital pyloric atresia (CPA) is a rare condition that presents as gastric outlet obstruction in the first few weeks of life. Isolated CPA typically carries a good prognosis but when associated with other conditions such as multiple intestinal atresia or epidermolysis bullosa (EB), the outcomes are generally poor. This report describes a four-day-old infant who presented with nonbilious emesis and weight loss in whom an upper gastrointestinal contrast study revealed gastric outlet obstruction determined to be consistent with pyloric atresia. The patient underwent operative repair via Heineke-Mikulicz pyloroplasty. Postoperatively, the patient continued to have severe diarrhea and was found to have desquamative enteropathy though had no skin findings consistent with EB. This report emphasizes consideration of CPA as a differential diagnosis for neonates presenting with nonbilious emesis and demonstrates the association between CPA and desquamative enteropathy without EB.

[Upper gastrointestinal duplication complicated by perforation in a child]. / Udvoenie verkhnikh otdelov zheludochno-kishechnogo trakta, oslozhnennoe perforatsiei u rebenka.

Gastrointestinal duplications are rare congenital malformations occurring in embryonic period of development of digestive system. These abnormalities are usually found in infancy or early childhood. Clinical presentation is extremely diverse depending on dimensions, localization and type of duplication. The authors present duplication of antral and pyloric parts of the stomach, the 1st segment of the duodenum and pancreatic tail. Mother with a 6-month-old child turned to the hospital. According to the mother, the child was sick for about 3 days when episodes of periodic anxiety first appeared. Upon admission, abdominal neoplasm was suspected after ultrasound. On the second day after admission, anxiety increased. There was impairment of appetite, and the child rejected food. Abdominal asymmetry in umbilical area was observed. Considering clinical data on intestinal obstruction, emergency transverse right-sided laparotomy was performed. A tubular structure was found resembling intestinal tube was found between the stomach and transverse colon. Surgeon found duplication of antral and pyloric parts of the stomach, the 1st segment of the duodenum and its perforation. During further revision, additional pancreatic tail was diagnosed. En-bloc resection of gastrointestinal duplications was carried out. Postoperative period was uneventful. Enteral feeding was initiated after 5 days, and the patient was transferred to surgical unit. The child was discharged after 12 postoperative days.

Analysis of the potential risk factors for defecation problems and their bowel management based on the long-term bowel function in patients with persistent cloaca: results of a nationwide survey in Japan.

AIM OF THE STUDY: We conducted a nationwide survey of persistent cloaca (PC) to determine its current status in Japan. This study clarifies the potential risk factors for defecation problems in patients with PC. METHODS: Patient information was obtained via questionnaire, and a total of 213 PC patients who responded to a questionnaire on defecation problems and their bowel functions were enrolled in this study. We evaluated the constipation, incontinence, and soiling as bowel functions. Univariate and multivariate analyses were performed using a logistic regression analysis to clarify the risk factors for defecation problems. RESULTS: Of 213 patients with PC, 55 (25.8%) had defecation problems. A multivariate logistic regression analysis showed that sacral agenesis, as an associated anomaly, was significantly associated with defecation problems (odds ratio [OR] 3.19, 95% confidence interval [CI] 1.11-9.16, p = 0.03). The other multivariate logistic regression analysis showed that the PC patients who underwent antegrade continence enema and regularly took laxatives after anorectoplasty had defecation problems (OR 12.4, 95% CI 2.35-65.6, p = 0.003, OR 2.84, 95% CI 1.24-6.55, p = 0.01). CONCLUSION: Sacral agenesis is the potential risk factor of defecation problems in the patients with PC who underwent anorectoplasty. Those patients require vigorous defecation management.

[Management Of Blader Exstrophy In Children At The CHU Gabriel Touré]. / Prise En Charge De l'Exstrophie Vesicale Dans Le Service De Chirurgie Pediatrique : CHU Gabriel Toure.

AIMS: To describe the clinical and evolutionary aspects of the primary closure of exstrophy at the CHU Gabriel Touré. MATERIALS AND METHODS: This was a retrospective and prospective study carried out from January 2014 to December 2019 in all the children admitted and operated on for bladder exstrophy at the CHU Gabriel Touré. RESULTS: We collected 35 cases of exstrophy, ie25 boys and 10 girls. The mean age at diagnosis was 4.8 months. The bladder plate was both normal and budded, ie 28.6% of cases. Plaque infection was found in 45.7%. A malformation was associated in 34.3% of cases. Primary plaque closure was achieved in all of our patients. Postoperative morbidity was 28.6% of cases and mortality 11.4% of cases. CONCLUSION: Bladder exstrophy is a rare malformation of the urogenital sphere, its management is complex and its mortality is not null.

OBJECTIFS: Décrire les aspects cliniques et évolutifs de la fermeture primaire de l'exstrophie au CHU Gabriel Touré. MATÉRIELS ET MÉTHODES: Il s'agissait d'une étude rétrospective et prospective réalisée de janvier 2014 à décembre 2019 chez tous les enfants admis et opérés pour exstrophie vésicale au CHU Gabriel Touré. RÉSULTATS: Nous avons colligés 35 cas d'exstrophie soit 25 garçons et 10 filles. L'âge moyen au moment du diagnostic était de 4,8 mois. La plaque vésicale était au tant normale que bourgeonnée soit 28,6 % des cas. Une infection de la plaque a été retrouvée dans 45,7%. Une malformation était associée dans 34,3% des cas. La fermeture primaire de la plaque a été réalisée chez tous nos patients. La morbidité post opératoire était de 28,6% des cas et la mortalité, 11,4% des cas. CONCLUSION: L'exstrophie vésicale est une malformation rare de la sphère urogénitale, sa prise en charge est complexe et sa mortalité n'est pas nulle.

Surgical management of Currarino syndrome in elderly patient with infected pre-sacral mass: Technical nuances and review of literature.

OBJECTIVE: Currarino Syndrome (CS) is a rare autosomal dominant genetic disorder that is defined by a triad of: presacral mass, anorectal malformations, and sacral bone dysplasia. Once discovered, these lesions are often surgically treated to avoid life threatening complications such as meningitis and malignant transformation of a sacral teratoma. As this syndrome is usually diagnosed in childhood, accurate diagnosis in adults presenting with this syndrome can be challenging and delay treatment. We present a case report with diagnostic and surgical management strategies of CS presenting in an elderly patient with accompanying review of literature. METHODS: We performed a literature review by searching PubMed, Ovid Embase, and Scopus electronic databases with the predetermined inclusion criteria of cases of CS in the adult population. RESULTS: A 70-year-old male with newly diagnosed CS and meningitis successfully underwent resection of his lesion as an interdisciplinary case between neurosurgery and colorectal surgery. At six-month follow up, the patient reports resolution of constipation and urinary symptoms, no longer has signs of infection, and remains neurologically full strength in his lower extremities. A review of literature revealed only 5 previously reported cases of CS presenting in the adult population with 3 of these cases requiring surgical intervention. CONCLUSION: Currarino Syndrome (CS) is an autosomal dominant genetic disorder characterized by a presacral mass, sacral bony deformities, and anorectal malformations. It is usually diagnosed in pediatric age group. In this article, we present a case of a 70-year-old male presenting with meningitis, encephalopathy, and gastrointestinal disturbances.

Persistent cloaca with fetal ascites: clinical features and perinatal management.

PURPOSE: Fetuses with persistent cloaca are known to develop urine or meconium backflow into the abdominal cavity caused by obstruction of the common channel, thus leading to fetal peritonitis with fetal ascites. We analyzed the impact of prenatal fetal ascites on postnatal clinical features and management. METHODS: This retrospective single-center cohort study was conducted to compare the perinatal parameters of patients with isolated persistent cloaca who were born and treated at our hospital between 1991 and 2021. The clinical features and management of those with and without fetal ascites were compared. RESULTS: Among the 17 eligible patients, fetal ascites were recognized in seven. The occurrence of fetal ascites was significantly related to preterm birth, higher birth weight z-score, birth via emergency cesarean delivery, low Apgar scores at 1 min and 5 min, higher C-reactive protein levels at birth, longer duration of oxygen administration, the need for a urinary drainage catheter at initial discharge, and shorter neonatal hospital stays. CONCLUSIONS: The postnatal management of patients with persistent cloaca with fetal ascites differed significantly from that of patients without fetal ascites. For patients with unexplained fetal ascites, magnetic resonance imaging may be helpful for determining the definite diagnosis of persistent cloaca.

Rare case of upper gastrointestinal hemorrhage due to accessory spleen: A case report.

RATIONALE: Upper gastrointestinal hemorrhage (UGIH) is defined as hemorrhage originating from the gastrointestinal tract proximal to the ligament of Treitz. The causes of UGIH include esophagitis, gastritis, peptic ulcers, Mallory-Weiss syndrome, and cancer. However, a rare cause of UGIH, such as an accessory spleen, may lead to serious complications if left untreated and can sometimes be very difficult to diagnose preoperatively. PATIENT CONCERNS: An 18-year-old man was admitted to the Department of Gastroenterology of our hospital due to "repeated black stool for 2 months with aggravation, accompanied by hematemesis for 9 days." He denied any history of hepatitis, trauma, or surgery. DIAGNOSIS: Laboratory evaluation revealed severe anemia (hemoglobin, 6.4 g/dL). Computed tomography revealed a mass measuring 127 mm in its largest dimension, located in the upper left abdomen, with varicose veins in the gastric fundus. Moreover, distended blue-purple tortuous veins were observed by gastroscopy in the gastric fundus. We believed the mass was likely an abnormally proliferating accessory spleen; however, the causes of severe anemia and gastrointestinal hemorrhage were unknown. INTERVENTIONS: After discussion in a multidisciplinary conference, the mass was completely resected laparoscopically, and the subserosal veins in the gastric fundus were sutured using absorbable threads. OUTCOMES: After the surgery, the patient recovered uneventfully without any complications. Clinicopathological examination showed that the mass was chronic congestive splenomegaly. Gastrointestinal hemorrhage secondary to an abnormally proliferating accessory spleen was confirmed as the diagnosis. Laboratory evaluation revealed hemoglobin at 12.1 g/dL 2 months after surgery. At the 12-month follow-up, the patient showed no recurrence of gastrointestinal hemorrhage. LESSONS: UGIH caused by accessory spleen is extremely rare. This entity should be considered in differential diagnosis of gastrointestinal hemorrhage. Surgical intervention is necessary for timely diagnosis and treatment in case of gastrointestinal hemorrhage in critical clinical situations.

Midgut malrotation presenting with hyperemesis gravidarum: A case report.

RATIONALE: Midgut malrotation is a rare congenital abnormality resulting from failure of complete intestinal rotation and subsequent fixation during early fetal development. There appeared to be no obvious symptoms in most patients, and a few patients may exhibit symptoms similar to hyperemesis gravidarum, such as nausea and vomiting. Here, we present a case of midgut malrotation presenting as hyperemesis gravidarum. PATIENT CONCERNS: A 27-year-old woman with an intrauterine pregnancy of 27 + 6 weeks complained of severe nausea and vomiting for 2 weeks. DIAGNOSIS: Magnetic resonance imaging showed obvious dilatation in the proximal part of the duodenum and gastric cavity and the absence of a duodenal path dorsal to the superior mesenteric artery, which was diagnosed as midgut malrotation. INTERVENTIONS: Considering that the patient's vital signs were stable, without manifestation of peritonitis or the risks of surgery to the fetus, conservative treatment was adopted. Unfortunately, the fetus developed severe hydrocephalus at 32 weeks. The patient and her family decided to abandon the fetus, and a mid-trimester-induced abortion was performed. OUTCOMES: The related symptoms completely disappeared after delivery, and the relevant examination after discharge also confirmed the presence of midgut malrotation without gastrointestinal discomfort within 1 year after delivery. LESSONS: Midgut malrotation can be considered as a differential diagnosis of hyperemesis gravidarum. Conservative treatment under close monitoring is desirable in pregnant women diagnosed with midgut malrotation.

Variety Of Gastrointestinal Duplications In Children: Experience At Tertiary Care Hospital.

BACKGROUND: Gastrointestinal duplication is a rare developmental anomaly that can be present anywhere along the GI tract, most often being found in ileum. The purpose of this study is to share our experience in evaluation of the presentation, investigations, management challenges and complications of patients with this very rare condition. METHODS: This descriptive case series was conducted at the Department of Paediatric Surgery, National Institute of Child Health Karachi, Pakistan, from April 2018 to October 2019. Data was analysed with regard to age, clinical presentation, investigations, surgical procedures, site and type of lesion, histopathology, complications and outcomes. RESULTS: A total of five patients were managed in one and half year. The patients' ages ranged from antenatally diagnosed foetus to 12 years old child. New-born who presented with antenatal diagnosis of abdominal cyst turned out to have duodenal duplication cyst. Among other four were thoracoabdominal duplication cyst, gastric duplication, jejunal duplication and ileal duplication, last two presented with perforation. Other presentations were abdominal pain, swelling and vomiting. Diagnosis was made on clinical ground, x-ray of abdomen, ultrasound and computed tomography. All cysts were resected successfully and patients remained asymptomatic till one year follow up except one patient who expired postoperatively due to liver failure. CONCLUSIONS: Enteric duplication can present in variety of ways depending on anatomical location. Prompt diagnosis and complete excision of cyst is the aim of treatment. However, these rare types of duplication are a challenge to operating surgeons.

Cholangitis secondary to obstructive choledocholithiases in an elderly woman with heterotaxy syndrome with polysplenia: report of a case and brief review of the literature.

The present study aims to report a rare case of obstructive choledocholithiases found in an elderly female with heterotaxy syndrome (HS) with polysplenia, and to review the available literature on hepatobiliary pathologies associated with this syndrome. We present the case of an 82-year-old female patient with multiple comorbidities who presented to our hospital with abdominal pain and jaundice. An abdominal ultrasound and subsequent computed tomography showed several obstructive choledocholithiases. Incidentally, an abnormal visceral arrangement consistent with HS with polysplenia was observed, including midline liver, semi-annular pancreas, intestinal malrotation, preduodenal portal vein and other vascular anomalies. Accordingly, the patient was diagnosed with cholangitis secondary to obstructive choledocholithiases and HS with polysplenia. She was admitted to the hospital for endoscopic retrograde cholangiopancreatography after medical stabilization. Unfortunately, her condition rapidly worsened and died a few hours after hospitalization due to septic shock. Only one case of choledocholithiases in HS has been previously reported in the literature. It is unclear whether the abnormal arrangement of abdominal organs may have a significant role in the development of this complication. Although biliary drainage might be hindered in the presence of anatomical variants such as (semi-)annular pancreas, intestinal malrotation and preduodenal portal vein, further studies are needed to determine if there is an association between these anomalies and the development of choledocholithasis.

Intestinal malrotation in extremely premature infants: a potential trap.

INTRODUCTION: Intestinal malrotation is life-threatening and often presents during infancy with bilious vomiting. The prevalence and presentation among extremely premature infants are unknown. METHODS: We retrospectively reviewed all infants born at less than 28 weeks' gestation diagnosed with symptomatic intestinal malrotation in a tertiary neonatal intensive care unit over a 10-year period (2010-2020). RESULTS: Seven of 514 (1.4%) extremely premature infants developed symptomatic intestinal malrotation during this period. All were non-syndromic. In comparison, the prevalence of symptomatic intestinal malrotation in 7382 infants ≥ 28 weeks' gestation admitted during the same period was 0.2%. Intestinal malrotation was confirmed at laparotomy in all extremely premature infants and six of seven had midgut volvulus. All but one presented with marked abdominal distension; none had bilious vomiting and only three had bilious gastric aspirates. A subacute onset with non-specific features such as recurrent apnoea and bradycardia, feed intolerance, and intermittent abdominal distension was common. All infants underwent a Ladd procedure. Two required extensive bowel resection resulting in short gut syndrome and three underwent further surgery for adhesive small bowel obstruction. One patient died at 10 months of age from respiratory failure but the others were well 1-3 years later. CONCLUSIONS: Symptomatic intestinal malrotation in extremely premature infants has a relatively high prevalence. It may present with marked abdominal distension without bilious vomiting, demanding a high index of suspicion. An atypical presentation, potential alternative abdominal pathologies, coexisting comorbidities, and concerns about survival in these fragile babies may deter the surgeon despite the opportunity of a good outcome.

Neurodevelopmental outcome of patients with congenital gastrointestinal malformations: a systematic review and meta-analysis.

AIM: Children with congenital gastrointestinal malformations may be at risk of neurodevelopmental impairment due to challenges to the developing brain, including perioperative haemodynamic changes, exposure to anaesthetics and postoperative inflammatory influences. This study aggregates existing evidence on neurodevelopmental outcome in these patients using meta-analysis. METHOD: PubMed, Embase and Web of Science were searched for peer-reviewed articles published until October 2019. Out of the 5316 unique articles that were identified, 47 studies met the inclusion criteria and were included. Standardised mean differences (Cohen's d) between cognitive, motor and language outcome of patients with congenital gastrointestinal malformations and normative data (39 studies) or the studies' control group (8 studies) were aggregated across studies using random-effects meta-analysis. The value of (clinical) moderators was studied using meta-regression and diagnostic subgroups were compared. RESULTS: The 47 included studies encompassed 62 cohorts, representing 2312 patients. Children with congenital gastrointestinal malformations had small-sized cognitive impairment (d=-0.435, p<0.001; 95% CI -0.567 to -0.302), medium-sized motor impairment (d=-0.610, p<0.001; 95% CI -0.769 to -0.451) and medium-sized language impairment (d=-0.670, p<0.001; 95% CI -0.914 to -0.425). Patients with short bowel syndrome had worse motor outcome. Neurodevelopmental outcome was related to the number of surgeries and length of total hospital stay, while no relations were observed with gestational age, birth weight, age and sex. INTERPRETATION: This study shows that children with congenital gastrointestinal malformations exhibit impairments in neurodevelopmental outcome, highlighting the need for routine screening of neurodevelopment during follow-up.

Communicating multiple tubular enteric duplication with toxic megacolon in an infant: A case report.

RATIONALE: Gastrointestinal tract duplication is a rare congenial anomaly which can be found anywhere along the gastrointestinal tract. While many patients are incidentally diagnosed during operation, in some cases it can present with severe gastrointestinal symptoms. In this case report, the patient presented with signs of toxic megacolon leading to rapid aggravation of inflammatory shock. PATIENT CONCERNS: A 49-day old male infant presented with fever, poor feeding, and severe abdominal distension. DIAGNOSIS: Abdominal ultrasonography was done. During the examination, a foley catheter was inserted through the anus to evaluate bowel patency and enable rectal decompression. The tip of the foley catheter was located in a separate narrower tubular lumen adjacent to the distended rectum. These findings suggested possibility of a tubular duplication cyst of the rectum as the culprit for the bowel obstruction. INTERVENTIONS: The patient underwent emergency laparotomy. Findings showed multiple tubular intestinal duplications involving the ileum, appendix, cecum, descending colon, sigmoid colon and rectum. The true lumen of the rectosigmoid colon was completely collapsed while the adjacent tubular cyst remained severely distended and stool passage was not possible. Decompression of the sigmoid colon was done with loop colostomy with both the wall of the true bowel and enteric cyst forming the colostomy orifice. OUTCOMES: After 40 days of postoperative care, the patient was discharged with no immediate complications. Four months after the initial operation, colostomy take-down and transanal rectal common wall division was done. No complications were observed. LESSONS: To our knowledge, this is the first case to be reported where a rare presentation of intestinal duplication resulted in an acute presentation toxic megacolon. Such emergency cases can be effectively treated with emergency surgical bowel decompression and elective common wall division.

Bladder exstrophy with exstrophic rectal duplication in an infant: An extremely rare case.

Exstrophic rectal duplication and its association with bladder exstrophy and anorectal malformation is an extremely rare clinical entity. This is a report of the second case of an exstrophic rectal duplication associated with bladder exstrophy in English literature. However, it is the first case, where all these anomalies were accompanied by an anorectal malformation.

A case of reversed intestinal rotation revealed by volvulus in adult: anatomo-radiological correlations.

We report a case of reversed rotation (RR) of the midgut, the rarest form of intestinal malrotation (IMR), revealed by a chronic volvulus, in a 42-year-old woman presenting with episodes of abdominal pain occurring after heavy meals. The complete preoperative diagnosis was obtained by contrast-enhanced computed tomography (CT). Classical signs of volvulus were associated with typical findings of RR comprising an unusual position of the third duodenum in front of the mesenteric vessels and a very unusual location of the transverse colon behind these vessels. Complete absence of fixation of the right colon allowed secondary volvulus. A detailed reminder of the embryology of IMR and RR is presented.