R A Quintero

Jackson Memorial Hospital, Miami, Florida, United States

Are you R A Quintero?

Claim your profile

Publications (175)640.12 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Objective: To evaluate the impact of selective intrauterine growth restriction (SIUGR) on monochorionic multiples treated with selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS). Methods: Perinatal survival was compared among TTTS patients with and without SIUGR. The TTTS+SIUGR group was defined as TTTS patients with donor twin weight <10(th) percentile. Multivariable logistic regression analyses identified factors associated with 30-day survival. Results: Of 369 patients, 65% (N=241) had TTTS+SIUGR. 30-day donor twin survival for the TTTS-only group was 84% vs. 75% in the TTTS+SIUGR group (p=0.0348). Stage III Donor-involved (Stage III Donor, Donor/Recipient) TTTS+SIUGR patients (N=110) had 66% 30-day donor survival. Multivariable logistic regression demonstrated that the TTTS-only group was twice as likely to achieve donor survival compared to the TTTS+SIUGR group (OR 2.01, 95%CI 1.11-3.66, p = 0.0214). In the TTTS+SIUGR group, patients not classified as Stage III Donor-involved were twice as likely to achieve donor survival as Stage III Donor-involved patients (OR 2.02, 95%CI 1.10-3.71, p = 0.0226). Conclusions: SIUGR, present in two-thirds of TTTS patients, was a risk factor for decreased donor survival. Patients with donor SIUGR and umbilical artery persistent or reversed end-diastolic flow (Quintero Stage III Donor-involved) were especially at risk.
    Journal of Maternal-Fetal and Neonatal Medicine. 09/2014;
  • Ultrasound in Obstetrics and Gynecology 08/2014; 44(2). · 3.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Treatment of twin-twin transfusion syndrome (TTTS) via the sequential selective laser photocoagulation of communicating vessels (SQLPCV) technique involves lasering the arteriovenous communications from the donor twin to the recipient twin first, followed by the arteriovenous communications from the recipient twin to the donor. Occluding the vascular communications in this particular order may result in transient intraoperative net transfusion to the donor twin and facilitate hemodynamic equilibrium, particularly to the volume depleted donor twin. Preliminary evidence suggests that the SQLPCV technique may result in improved perinatal outcomes compared with the standard selective (SLPCV) laser surgical approach. In this article, we describe the pathophysiological basis for this surgical approach, delineate the surgical technique, review the literature, and elaborate on the outstanding questions of the SQLPCV treatment of TTTS.
    American Journal of Perinatology 06/2014; · 1.57 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective To analyze perinatal outcome in monoamniotic (MA) pregnancies that underwent antenatal surgical interventions for fetal complications. Methods Review of all MA pregnancies treated with antenatal surgical interventions in 3 Fetal Treatment Centers between 2000 and 2013. Indications were twin-twin transfusion syndrome, twin reversed arterial perfusion sequence, discordant anomalies or elective reduction. We analyzed associations between indication, type of intervention, perinatal survival and gestational age (GA) at birth, and compared our results with a systematic review of the literature. ResultsFifty-eight MA pregnancies were included. Median GA at treatment was 18.0 weeks (range: 13.1 - 33.0). Procedures included cord coagulation plus transection (n = 42), cord coagulation without transection (n = 7), laser coagulation of placental anastomoses (n = 7), and one case each with interstitial laser and radiofrequency ablation. Median GA at birth was 34 weeks (range 16.0 - 41.0) and 75% (53/71) of fetuses intended to survive indeed survived. Literature review: 20 articles, reporting on a total of 45 cases of surgically treated MA pregnancies, showing similar outcome results. Conclusion We present the largest series concerning surgical interventions in complicated MA pregnancies. Despite being rare in experienced hands, a 75% survival is achieved. Collaboration between centers, data-sharing and benchmarking may further improve outcome. This article is protected by copyright. All rights reserved.
    Prenatal Diagnosis 03/2014; · 2.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Objective: To report our preliminary clinical experience in the antenatal correction of open spina bifida using a fetoscopic approach and a simplified closure technique. Methods: Four fetuses with lumbar-sacral defects were operated in utero from 25 to 27 weeks. Surgeries were performed percutaneously under general anesthesia using three trocars and partial carbon dioxide insufflation. After dissection of the neural placode, the surrounding skin was closed over a cellulose patch using a single continuous stitch. Results: Surgical closure was successful in three of the 4 cases. All successful cases showed improvement of the hindbrain herniation and no neurosurgical repair was required in two cases. Delivery occurred between 31 to 33 weeks, and no fetal or neonatal deaths occurred. Ventriculoperitoneal shunting was not needed in 2/3 successful cases. Conclusions: Our preliminary experience suggests that definitive fetoscopic repair of open spina bifida is feasible using our innovative surgical technique. A phase I trial for the fetoscopic correction of OSB with this technique is currently being conducted.
    The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 12/2013; · 1.36 Impact Factor
  • Source
    Ultrasound in Obstetrics and Gynecology 10/2013; 42(s1). · 3.56 Impact Factor
  • American journal of obstetrics and gynecology 03/2013; · 3.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Objectives: To assess whether the observed vs. expected lung-to-head ratio (o/e LHR) corrects for the dependence of the LHR on gestational age. Study Design: Published data on right lung area (LA) and LHR were used to plot the 50(th) percentile and different fixed values of the o/e LHR (e.g., 30%) against gestational age from 16-32 weeks. The Z-scores for various fixed o/e LHR values and similar percent value of lung area were calculated. The effect of using a fixed LHR or a fixed o/e LHR were tested against gestational age. The o/e LHR- equivalent to a fixed LHR of 1.0 was assessed against gestational age. Results: The LHR and the o/e LHR both increase with gestational age. The Z-scores of a given fixed value of the o/e LHR (e.g., 30%) is not similar to the Z-score of the same percent (e.g., 30%) of the expected LA, and thus identify different proportions of subjects. A fixed o/e LHR (e.g., 30%) results in different populations, depending on the gestational age. The o/e LHR equivalent to an LHR value of 1.0 decreases from 80% at 16 weeks to 30% at 32 weeks. Conclusions: The o/e LHR is not independent of gestational age. Studies using this parameter should be interpreted with caution.
    The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 10/2012; · 1.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to evaluate the phenomenon of vascular ischemic limb necrosis in twin-twin transfusion syndrome (TTTS). This was a multicenter retrospective review of ischemic limb necrosis in patients with TTTS. Twenty cases of fetal ischemic limb necrosis in association with TTTS were identified from 10 fetal medicine centers. The recipient was affected in 19 cases, and the lower limb was affected in 17 cases. The extent of the damage correlated with TTTS severity. Eighty percent of limb defects (16/20) clearly were unrelated to laser treatment (3 cases untreated, 7 cases after amnioreduction, 6 cases present at time of laser). The recipient was relatively polycythemic in 5 of 7 cases in which neonatal or fetal hemoglobin/hematocrit levels were available. Ischemic limb necrosis is a rare complication of TTTS. The lesion is unrelated to therapy and may be the result of polycythemia, hypertension, and vasoconstriction.
    American journal of obstetrics and gynecology 08/2012; 207(2):131.e1-10. · 3.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: To report the performance of fetal bronchoscopy in a case of pulmonary sequestration. Materials and Methods: A 24 year-old female, Gravida 2, Para 1, was referred at 27.5 weeks with a large fetal left lung mass with marked right mediastinal shift and no visible normal left lung. Differential diagnosis included possible bronchial atresia. Results: The patient underwent fetal laryngoscopy and fetal bronchoscopy at 31.5 weeks. The right lung and a portion of the left lung expanded during surgery as a result of bronchial lavage. Bronchial atresia or bronchogenic cyst were not found. Pregnancy continued uneventfully, with continuous growth of the right lung and a small amount of left lung. The patient delivered vaginally at term. The baby underwent thoracoscopic resection of a pulmonary sequestration at 10.5 months of age and did well. Conclusion: Fetal bronchoscopy is feasible. The procedure may prove useful in the differential diagnosis and in the potential treatment of different fetal lung lesions, as well as aid in the understanding of the role of bronchial obstruction as a common pathophysiologic mechanism for different fetal lung masses. Risks and benefits of fetal bronchoscopy warrant further experience.
    The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 05/2012; 25(11):2354-8. · 1.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: To evaluate pulmonary growth and development after fetoscopic intraluminal tracheal occlusion (FITO) using a modified 8-mm Z-stent in an ovine model of congenital left-sided diaphragmatic hernia (CDH). Methods: Thirty-three time-dated ewes were studied: Group I: healthy controls; Group II: CDH controls (untreated); Group III: CDH treated with FITO. CDH was created in Groups II and III at 70-80 days' gestation. FITO was performed at 100-110 days. Left lung histological, morphometric, immunohistochemical and biochemical studies were conducted after delivery and euthanasia at 138 days. Results: Fifteen (45%) animals (Group I: 3; Group II: 5; Group III: 7) were available for analysis. The left lung parenchymal volume to fetal weight ratios were similar between Groups I and III (p = 0.24), and higher than Group II (p < 0.05III (79 versus 75%, p = 0.26), compared to 41% in Group II (p < 0.05). Pulmonary hypoplasia occurred in 1/7 (16%) in the FITO group, compared to 100% in Group II and 0% in Group I (p = .003). DNA and protein were significantly increased in Group III (p < 0.001). The concentration of type II pneumocytes was similar between healthy controls and the FITO group, and was paradoxically increased in untreated hernia fetuses. There was no histological evidence of tracheal injury. Conclusion: FITO with a modified 8-mm Z-stent is associated with lung growth and maturation similar to controls without obvious deleterious effects. A phase I clinical trial of FITO with the modified 8-mm Z-stent in severe CDH patients seems warranted.
    The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 05/2012; 25(11):2346-53. · 1.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The prenatal diagnosis of a nasopharyngeal teratoma carries a very grave prognosis. Although these tumors constitute only 9% of all teratomas, all previous cases diagnosed antenatally have been associated with either fetal demise or emergent surgery at birth. Of the fetuses that survive to birth, delivery can be associated with airway obstruction and multiple postnatal surgeries. These complications could be averted if the tumor could be safely treated in utero. We hereby report the successful treatment of an oral teratoma via operative fetoscopy, with the birth of a healthy infant at term.
    American journal of obstetrics and gynecology 04/2012; 207(1):e12-5. · 3.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To assess the ability of a three-layer graft in the closuse of large fetal skin defects. Ovine fetuses underwent a large (4 × 3 cm) full-thickness skin defect over the lumbar region at 105 days' gestation (term = 140 days). A bilaminar artificial skin was placed over a cellulose interface to cover the defect (3-layer graft). The skin was partially reapproximated with a continuous nylon suture. Pregnancy was allowed to continue and the surgical site was submitted to histopathological analysis at different post-operative intervals. Seven fetuses underwent surgery. One maternal/fetal death occurred, and the remaining 6 fetuses were analyzed. Artificial skin adherence to the wound edges was observed in cases that remained in utero for at least 15 days. Neoskin was present beneath the silicone layer of the bilaminar artificial skin. Our study shows that neoskin can develop in the fetus using a 3-layer graft, including epidermal growth beneath the silicone layer of the bilaminar skin graft. These findings suggest that the fetus is able to reepithelialise even large skin defects. Further experience is necessary to assess the quality of this repair.
    The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 08/2011; 24(10):1243-8. · 1.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We sought to develop a gestational age-independent sonographic parameter to characterize lung growth. Reported descriptors of lung growth, including lung-to-head circumference (HC) ratio (LHR) and observed/expected LHR, were examined. A new index, the quantitative lung index (QLI) was derived using published data on HC and the area of the base of the right lung. Neither the LHR nor the observed/expected LHR proved to be gestational age independent. Right lung growth can be expressed using the following formula: QLI = lung area/(HC/10)^2. The 50th percentile of the QLI remained constant at approximately 1.0 for the gestational age between 16-32 weeks. A small lung (<1st percentile) was defined as a QLI <0.6. Fetal right lung growth can be adequately described using the QLI, independent of gestational age. Further studies are needed to assess the clinical accuracy of the QLI in characterizing fetal right lung growth.
    American journal of obstetrics and gynecology 07/2011; 205(6):544.e1-8. · 3.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We sought to describe stage-specific perinatal outcomes after selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome. Patients with twin-twin transfusion syndrome underwent SLPCV preferentially using sequential vs standard laser technique. Patient characteristics and outcome data were examined by Quintero stage. Of 682 consecutive women studied, the Quintero stage distribution was: 114 stage I (17%), 177 stage II (26%), 328 stage III (48%), and 63 stage IV (9%). Perinatal survival of at least 1 twin did not differ according to stage (I-92%, II-93%, III-88%, IV-92%; P = .30). However, dual twin survival differed by stage (I-79%, II-76%, III-59%, IV-68%; P < .01), primarily because stage III pregnancies were associated with decreased donor twin survival (P < .01). Sequential SLPCV was associated with improved donor survival, independent of stage (odds ratio, 1.67; 95% confidence interval, 1.16-2.40; P < .01). Stage-specific perinatal outcomes after laser therapy may assist physicians in patient counseling and in planning future studies.
    American journal of obstetrics and gynecology 03/2011; 204(5):393.e1-6. · 3.28 Impact Factor
  • Journal of perinatal medicine. 01/2011; 39(2):107-112.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic (MC) twin pregnancies, characterized by the development of unbalanced chronic blood transfer from one twin, defined as donor twin, to the other, defined as recipient, through placental anastomoses. If left untreated, TTTS is associated with very high perinatal mortality and morbidity rates, due to a combination of fetal and/or obstetric complications. The reported prevalence is 10-15% of all MC twins, or about 1 in 2000 pregnancies. This consensus document reviews available evidence and offers practical guidance to clinicians by providing recommendations on various aspects concerning diagnosis and management of TTTS.
    Journal of Perinatal Medicine 12/2010; 39(2):107-12. · 1.95 Impact Factor
  • Source
    Revista colombiana de obstetricia y ginecología 12/2010; 61(4):341-347.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Umbilical artery Doppler velocimetry waveform notching has long been associated with umbilical cord abnormalities, such as distortion, torsion, and/or compression (i.e., constriction). The physical mechanism by which the notching occurs has not been elucidated. Flow velocity waveforms (FVWs) from two-dimensional pulsatile flows in a constricted channel approximating a compressed umbilical cord are analyzed, leading to a clear relationship between the notching and the constriction. Two flows with an asymmetric, semi-elliptical constriction are computed using a stabilized finite-element method. In one case, the constriction blocks 75% of the flow passage, and in the other the constriction blocks 85%. Channel width and prescribed flow rates at the channel inflow are consistent with typical cord diameters and flow rates reported in the literature. Computational results indicate that waveform notching is caused by flow separation induced by the constriction, giving rise to a vortex (core) wave and associated eddies. Notching in FVWs based on centerline velocity (centerline FVW) is directly related to the passage of an eddy over the point of measurement on the centerline. Notching in FVWs based on maximum cross-sectional velocity (envelope FVW) is directly related to acceleration and deceleration of the fluid along the vortex wave. Results show that notching in envelope FVW is not present in flows with less than a 75% constriction. Furthermore, notching disappears as the vortex wave is attenuated at distances downstream of the constriction. In the flows with 75 and 85% constriction, notching of the envelope FVW disappears at ∼3.8 and ∼4.3 cm (respectively) downstream of the constriction. These results are of significant medical importance, given that envelope FVW is typically measured by commercial Doppler systems.
    AJP Regulatory Integrative and Comparative Physiology 10/2010; 300(1):R76-84. · 3.28 Impact Factor
  • Source
    Article: Chop, chop.
    R Quintero
    Ultrasound in Obstetrics and Gynecology 07/2010; 36(1):6-9. · 3.56 Impact Factor

Publication Stats

2k Citations
640.12 Total Impact Points


  • 2012–2014
    • Jackson Memorial Hospital
      • Department of Fetal Therapy
      Miami, Florida, United States
    • Venezuelan Institute for Scientific Research
      Caracas, Distrito Federal, Venezuela
  • 2013
    • University of São Paulo
      San Paulo, São Paulo, Brazil
  • 2009–2012
    • University of Miami
      • Department of Obstetrics and Gynecology
      Coral Gables, FL, United States
  • 2006–2011
    • University of Southern California
      • Department of Obstetrics and Gynecology
      Los Angeles, CA, United States
    • Florida Heart Research Institute
      Miami, Florida, United States
    • Chang Gung Memorial Hospital
      T’ai-pei, Taipei, Taiwan
  • 2010
    • University of Miami Miller School of Medicine
      Miami, Florida, United States
  • 2006–2010
    • University of South Florida
      • • Civil and Environmental Engineering
      • • Department of Obstetrics and Gynecology
      • • Morsani College of Medicine
      Tampa, FL, United States
  • 2008
    • Università degli Studi di Bari Aldo Moro
      Bari, Apulia, Italy
    • Society for Maternal-Fetal Medicine
      Tampa, Florida, United States
  • 2007–2008
    • Central University of Venezuela
      Caracas, Distrito Federal, Venezuela
  • 2003
    • Hospital Universitario de Caracas
      Caracas, Distrito Federal, Venezuela
    • Mater Hospital
      Brisbane, Queensland, Australia
  • 2001
    • St. Joseph's Hospital
      Savannah, Georgia, United States
  • 1993–1997
    • Wayne State University
      • Department of Obstetrics and Gynecology
      Detroit, MI, United States
  • 1995
    • Detroit Medical Center
      Detroit, Michigan, United States