Randomized controlled trial of twin-twin transfusion syndrome laser surgery: the sequential trial.

BACKGROUND: Intraoperative blood transfer between twins during laser surgery for twin-twin transfusion syndrome can vary by surgical technique and has been proposed to explain differences in donor twin survival. OBJECTIVE: This trial compared donor twin survival with 2 laser techniques: the sequential technique, in which the arteriovenous communications from the volume-depleted donor to the volume-overloaded recipient are laser-occluded before those from recipient to donor, and the selective technique, in which the occlusion of the vascular communications is performed in no particular order. STUDY DESIGN: A single-center, open-label, randomized controlled trial was conducted in which twin-twin transfusion syndrome patients were randomized to sequential vs selective laser surgery. Nested within the trial, a second trial randomized patients with superficial anastomoses (arterioarterial and venovenous) to ablation of these connections first (before ablating the arteriovenous anastomoses) vs last. The primary outcome measure was donor twin survival at birth. RESULTS: A total of 642 patients were randomized. Overall donor twin survival was similar between the 2 groups (274 of 320 [85.6%] vs 271 of 322 [84.2%]; odds ratio, 1.12 [95% confidence interval, 0.73-1.73]; P=.605). Superficial anastomoses occurred in 177 of 642 cases (27.6%). Donor survival was lower in the superficial anastomosis group vs those with only arteriovenous communications (125 of 177 [70.6%] vs 420 of 465 [90.3%]; adjusted odds ratio, 0.33 [95% confidence interval, 0.20-0.54]; P<.001). In cases with superficial anastomoses, donor survival was independent of the timing of ablation or surgical technique. The postoperative mean middle cerebral artery peak systolic velocity was lower in the sequential vs selective group (1.00±0.30 vs 1.06±0.30 multiples of the median; P=.003). Post hoc analyses showed 2 factors that were associated with poor overall donor twin survival: the presence or absence of donor twin preoperative critical abnormal Doppler parameters and the presence or absence of arterioarterial anastomoses. Depending on these factors, 4 categories of patients resulted: (1) Category 1 (347 of 642 [54%]), no donor twin critical abnormal Doppler + no arterioarterial anastomoses: donor twin survival was 91.2% in the sequential and 93.8% in the selective groups; (2) Category 2 (143 of 642 [22%]), critical abnormal Doppler present + no arterioarterial anastomoses: donor survival was 89.9% vs 75.7%; (3) Category 3 (73 of 642 [11%]), no critical abnormal Doppler + arterioarterial anastomoses present: donor survival was 94.7% vs 74.3%; and (4) Category 4 (79 of 642 [12%]), critical abnormal Doppler present + arterioarterial anastomoses present: donor survival was 47.6% vs 64.9%. CONCLUSION: Donor twin survival did not differ between the sequential vs selective laser techniques and did not differ if superficial anastomoses were ablated first vs last. The donor twin's postoperative middle cerebral artery peak systolic velocity was improved with the sequential vs the selective approach. Post hoc analyses suggest that donor twin survival may be associated with the choice of laser technique according to high-risk factors. Further study is needed to determine whether using these categories to guide the choice of surgical technique will improve outcomes.

Vertical distribution and risk assessment of pharmaceuticals and other micropollutants in southern North Sea coastal waters.

Pharmaceutical compounds are micropollutants of emerging concern, as well as other classes of chemicals such as UV filters and artificial sweeteners. They enter marine environments via wastewater treatment plants, aquaculture runoff, hospital effluents, and shipping activities. While many studies have investigated the presence and distribution of these pollutants in numerous coastal areas, our study is the first to focus on their occurrence, spatial distribution, and vertical distribution in the sea surface microlayer (SML) and the near-surface layer of marine environments. We analyzed 62 pharmaceutical compounds, one UV filter, and six artificial sweeteners from the SML to the corresponding underlying water (0 cm, 20 cm, 50 cm, 100 cm, and 150 cm) at four stations in the southern North Sea. One station is the enclosed Jade Bay, one is the Weser estuary at Bremerhaven, and the other two stations (NS_7 and NS_8) are in the open German Bight. Jade Bay receives pollutants from surrounding wastewater treatment plants, while the Weser estuary receives pollutants from cities like Bremerhaven, which has dense populations and industrial activities. Concentrations of pharmaceutical compounds were higher in the upper water layers (from the SML to 20 cm). Eleven pharmaceutical compounds (caffeine, carbamazepine, gemfibrozil, ibuprofen, metoprolol, salicylic acid, clarithromycin, novobiocin, clindamycin, trimethoprim, and tylosin) were detected in >95 % of our samples. One UV filter (benzophenone-4) was found in 83 % and three artificial sweeteners (acesulfame, saccharin, and sucralose) in 100 % of all our samples. All artificial sweeteners posed high risks to the freshwater invertebrate Daphnia magna. Understanding the spatial and vertical distribution of pharmaceuticals and other micropollutants in marine environments may be essential in assessing their dispersal and detection in other aquatic environments.

Clinical assessment of the fetal right Quantitative Lung Index.

OBJECTIVES: We have previously described gestational-age-independent sonographic indices to assess fetal lung size in the right and left lungs: The Quantitative Lung Index for the right lung (QLI-R) and for the left lung (QLI-L), respectively. The purpose of this study was to evaluate the clinical cutoff point of the QLI-R to predict pulmonary hypoplasia and neonatal death. MATERIALS AND METHODS: Retrospective assessment of the QLI-R in patients with left-sided congenital diaphragmatic hernia (CDH-L) and other fetal conditions at risk for fetal pulmonary hypoplasia. Cross-section and longitudinal assessment of the behavior of the QLI-R in untreated and treated patients. ROC curve analysis to determine the optimal cutoff point of the QLI-R in predicting neonatal death. RESULTS: One hundred eighteen patients with CDH-L and other fetal conditions at risk for pulmonary hypoplasia had QLI-R measurements done. Seventeen patients were excluded for various reasons. Eleven patients with conditions other than CDH-L but at risk for pulmonary hypoplasia were used for intraclass coefficient measurements of the QLI-R. Ninety patients had CDH-L, of which 78 did not undergo antenatal intervention and in which the cutoff point for pulmonary hypoplasia and neonatal demise was assessed. Stent tracheal occlusion was performed in the remaining 12 patients with CDH-L, in which the behavior of the QLI after surgery was assessed. Analysis of the ICC showed an overall intra-rater reliability of 0.985 (Cronbach's Alpha-based). There was no correlation between gestational age and QLI-R (-0.73, Pearson correlation, p = .72). Twenty-six of the 78 patients (33%) with CDH-L managed expectantly had a neonatal demise. A QLI-R equal to or less than 0.45 was significantly predictive of neonatal demise (area under the curve 0.64, p = .046, sensitivity 77%). Nine of the 12 patients (75%) that underwent tracheal occlusion had neonatal survival. Of these, 10 had serial assessments of the QLI-R after surgery. An increase in the QLI-R of 0.11 was associated with a tendency for neonatal survival (p = .056). CONCLUSION: Our study confirms that the QLI-R is a gestational-age-independent measurement of fetal lung size, with a high degree of reproducibility. In a population of expectantly managed CDH-L patients, a cutoff value of the QLI-R of 0.45 or lower is predictive of neonatal death from pulmonary hypoplasia. The QLI-R can be used to monitor fetal lung growth after tracheal occlusion, and an increase in the QLI-R is suggestive of neonatal survival. Further prospective studies are needed to confirm these findings and to explore the use of the QLI in other populations at risk for pulmonary hypoplasia and consequent neonatal demise.

Fetoscopic demonstration of feto-fetal hemorrhage before actual demise of a monochorionic twin, successful antenatal treatment, and narrative review of the literature.

Feto-fetal hemorrhage (FFH) through placental vascular anastomoses is believed to be responsible for the death or damage of a "second twin" after the demise of a "first twin (co-twin)" in monochorionic twin pregnancies. However, the timing of FFH has been difficult to determine. The resulting anemia in the surviving twin can be suspected by the finding of an elevated middle cerebral artery peak-systolic velocity (MCA-PSV), but this elevation may lag for at least 4 h after the demise of the first twin. Knowledge of the timing of FFH may have important clinical implications, as it may dictate if and when attempts to prevent death or damage to the second twin by delivery or intrauterine fetal transfusion would be warranted. We present a case that supports the notion that FFH occurs before the actual demise of the first twin. A review of the literature was also conducted.

Percutaneous/mini-laparotomy fetoscopic repair of open spina bifida: a novel surgical technique.

Open spina bifida is the most common congenital anomaly of the central nervous system compatible with life. Prenatal repair of open spina bifida via open maternal-fetal surgery has been shown to improve postnatal neurologic outcomes, including reducing the need for ventriculoperitoneal shunting and improving lower neuromotor function. Fetoscopic repair of open spina bifida minimizes the maternal risks while providing similar neurosurgical outcomes to the fetus. The following 2 fetoscopic techniques are currently in use: (1) the laparotomy-assisted approach, and (2) the percutaneous approach. The laparotomy-assisted fetoscopic technique appears to be associated with a lesser risk of preterm birth than the percutaneous approach. However, the percutaneous approach avoids laparotomy and uterine exteriorization and is associated with lesser anesthesia risk and improved maternal postsurgical recovery. The purpose of this article was to describe our experience with a modified surgical approach, which we call percutaneous/mini-laparotomy fetoscopy, in which access to the uterus for one of the ports is done via a mini-laparotomy, whereas the other ports are inserted percutaneously. This technique draws on the benefits of both the laparotomy-assisted and the percutaneous techniques while minimizing their drawbacks. This surgical approach may prove invaluable in the prenatal repair of open spina bifida and other complex fetal surgical procedures.

The quantitative lung index: the left lung.

OBJECTIVE: We have previously described a gestational age-independent sonographic parameter to assess fetal lung growth in the right lung (right quantitative lung index, or QLI-R). The purpose of this study was to develop a similar sonographic parameter to assess the growth of the left lung in the fetus, independent of gestational age, or QLI-L. STUDY DESIGN: A new index, the QLI-L was derived using published formulas for the head circumference (HC) and the area of the base of the left lung (LA), with the corresponding percentiles. RESULTS: Left lung growth can be expressed using the following formula: QLI-L=LAL(HC12)2. The 50th percentile of the QLI-L remained approximately constant at 1.0 for the GA between 16-32 weeks. A small left lung (<1st percentile) was defined as a QLI-L < 0.5. CONCLUSIONS: Fetal left lung growth can be adequately described independent of gestational age using the QLI-L. Further experience is needed to assess the clinical accuracy of the QLI-L in characterizing fetal left lung growth.

Fetal blood gases after in utero carbon dioxide insufflation for percutaneous fetoscopic spina bifida repair.

BACKGROUND: Prenatal repair of open spina bifida via the percutaneous fetoscopic approach does not require maternal laparotomy, hysterotomy, or exteriorization of the uterus. This technique requires intrauterine partial CO2 insufflation. Limited data exist on the physiological effects of CO2 insufflation on human fetuses, with no data on open spina bifida repair performed using the entirely percutaneous fetoscopic surgical technique. OBJECTIVE: Our aim was to examine the effects of intrauterine partial CO2 insufflation on fetal blood gases after percutaneous fetoscopic open spina bifida repair. STUDY DESIGN: This was a prospective study of patients who underwent percutaneous fetoscopic open spina bifida repair from February 2019 to July 2020. Fetal cordocentesis of the umbilical vein was performed in cases with favorable access to the umbilical cord. The umbilical vein cord blood samples were obtained under ultrasound guidance immediately at the conclusion of the open spina bifida repair. Simultaneous maternal arterial blood gas samples were also obtained. The results are reported as median (range). RESULTS: Of the 20 patients who underwent percutaneous fetoscopic open spina bifida repair during the study period, 7 patients (35%) underwent fetal blood sampling. The gestational age at the time of surgery was 27.4 (24.0-27.9) weeks and the operative time was 183 (156-251) minutes. The CO2 exposure time was 122 (57-146) minutes with maximum pressure of 13.5 (12.0-15.0) mm Hg. Fetal umbilical vein results were as follows: pH 7.35 (7.30-7.39), partial pressure of O2 56.2 (47.1-99.9) mm Hg, partial pressure of CO2 43.8 (36.2-53.0) mm Hg, HCO3 23.9 (20.1-25.6) mmol/L, and base excess -2.2 (-4.5 to -0.4) mmol/L. Simultaneous maternal arterial blood gas results were as follows: pH 7.37 (7.28-7.42), partial pressure of O2 187.5 (124.4-405.2) mm Hg, partial pressure of CO2 36.6 (30.7-46.0) mm Hg, HCO3 21.3 (18.0-22.8) mmol/L and base excess -3.2 (-5.9 to -1.8) mmol/L. CONCLUSION: Despite prolonged CO2insufflation of the uterus, fetal umbilical vein pH and base excess values did not approach those associated with potentially pathologic fetal acidemia.

Neurodevelopmental outcome of monochorionic twins with selective intrauterine growth restriction (SIUGR) type II: laser versus expectant management.

OBJECTIVE: To compare the neurodevelopmental outcome of monochorionic-diamniotic twins (MCDA) with type II selective intrauterine growth restriction (SIUGR-II) managed in utero either expectantly or with laser. MATERIALS AND METHODS: Postnatal neurodevelopmental assessment was conducted on the children of patients that had been antenatally diagnosed with SIUGR-II between 16 and 26 weeks gestational age (GA) and that had been randomly assigned to expectant management (EM) versus laser therapy (LT). The assessment was conducted by trained specialists using the Battelle Developmental Inventory (BDI-2). BDI-2 total and domain (adaptive, personal-social, communication, motor, and cognitive) composite scores for the appropriately grown (AGA) and growth-restricted (IUGR) twins were compared by treatment arm. RESULTS: Twenty patients diagnosed with SIUGR had undergone block randomization between two centers to either expectant management (EM) (6) or laser therapy (LT) (14). The mean (SD) GA at diagnosis was no different between the EM and LT groups [21.5 (2.0) versus 21.1 (2.8) weeks, p = .7414, respectively]. However, GA at delivery was significantly lower in the EM versus LT groups [28.3 (1.8) versus 33.4 (3.8) weeks, p = .0039]. At 6 months, all 20 AGA babies were alive, whereas only 3/6 (50%) of the IUGR babies in the EM group and 4/14 (29%) in the LT group were alive (p = .6126). One family in the EM group and two families in the LT group declined BDI-2 assessment. The mean (SD) age at BDI-2 assessment was no different between the EM and LT groups [75.6 (14.4) versus 70.7 (18.2) months, p = .5618, respectively]. For the AGA children, there were no significant differences in total BDI-2 scores for the EM versus LT [97.4 (10.4) versus 98.0 (19.6), p = .8741], nor in any of the domain composite scores. For the IUGR children, no statistically significant differences were detected in total BDI-2 scores between the EM and LT [72.0 (31.1) versus 92.8 (22.1), p = .643], nor in any of the domain composite scores. The comparison of standardized scores between the AGA and IUGR pairs was significantly different, but within the normal range. CONCLUSIONS: Neurodevelopmental outcomes for SIUGR-II MCDA twins were similarly favorable, whether managed expectantly or with laser treated. However, the significantly different GA at delivery (28.3 versus 33.4 weeks, p = .0039, expectant versus laser, respectively) may suggest improved outcomes in laser-treated patients in a larger cohort.

Microsurgical Anatomy Review of Bifrontal Limited Transbasal Approach - Quantitative and Anatomy Study.

INTRODUCTION: The bifrontal transbasal approach is an anterior midline skull base approach to anterior skull base, sellae region and, if needed, to posterior skull base in the midline, often used for tumoral lesions but also useful for vascular or infectious pathologies. METHODS: Descriptive anatomic study, 5 formalin-fixed human cadaveric heads were used injected with colored silicone. The dissection was made step-by-step to describe every anatomic structure encountered. The working distance was obtained from the posterior wall of the frontal sinus with and without orbital rim to the pituitary stalk, the sellae, the pontomedullary sulcus, and the anterior margin of the foramen magnum. RESULTS: Stepwise anatomic dissection was performed dividing the surgical technique into 6 stages: soft-tissue stage, bone stage, sinus stage, clival stage, intradural, and measurements. The objective of making the supraorbital osteotomy was to improve the vision over the neural structures without brain retraction and limited to the midline supraorbital rim to avoid aggressive manipulation and injury to the orbit. The working distances measured with the orbital rim were on average: to the pituitary stalk, 70.5 mm; to the sellae, 81.3 mm; to the pontomedullary sulcus, 97 mm; and the foramen magnum, 99.5 mm. Without the orbital rim measures were: to the pituitary stalk, 57 mm; to the sellae, 62.5 mm; to the pontomedullary sulcus, 96 mm; and the foramen magnum, 98.5 mm. CONCLUSIONS: The addition of osteotomies including removing of the orbital rim improves the access to the central skull base with special benefits on the working distances to the sellae region.

Comparison Between Transcortical and Interhemispheric Approaches to the Atrium of Lateral Ventricle Using Combined White Matter Fiber Dissections and Magnetic Resonance Tractography.

OBJECTIVE: The objective of this study was to compare transcortical and posterior interhemispheric approaches to the atrium using a combined approach of white matter fiber dissections and magnetic resonance (MR) tractography. METHODS: Ten cerebral hemispheres were examined and dissected from the lateral-to-medial surface and from the medial-to-lateral surface, with special attention to the white matter tracts related to the atrium. MR tractography was used to show the relationship of three-dimensional white matter fibers with the atrium of the lateral ventricle and to compare with cadaveric dissection results. RESULTS: The atrium was related laterally to the superior longitudinal fasciculus II and III, middle longitudinal fasciculus, arcuate fasciculus, vertical occipital fasciculus, and sagittal stratum. Medially, it is related to the superior longitudinal fasciculus I, cingulum, sledge runner, and forceps major. CONCLUSIONS: A combined approach of cadaveric white matter fiber dissections and MR tractography were used to describe the main white matter tracts related to the posterior interhemispheric approach and the transcortical approach, providing an in-depth understanding of the three-dimensional anatomy of white matter fibers and the atrium. In the present study, among approaches examined, the posterior interhemispheric parasplenial transprecuneus approach placed fewer eloquent tracts at risk; however, traversing the sledge runner and the forceps major is unavoidable by this approach.

Microsurgical Anatomy of the Insular Region and Operculoinsular Association Fibers and its Neurosurgical Application.

OBJECTIVE: To analyze the three-dimensional relationships of the operculoinsular compartments, using standard hemispheric and white matter fiber dissection and review the anatomy of association fibers related to the operculoinsular compartments of the Sylvian fissure and the main white matter tracts located deep into the insula. The secondary aim of this study was to improve the knowledge on this complex region to safely address tumor, vascular, and epilepsy lesions with an integrated perspective of the topographic and white matter fiber anatomy using 2D and 3D photographs. METHODS: Six cadaveric hemispheres were dissected. Two were fixed with formalin and the arteries were injected with red latex dye; the remaining four were prepared using the Kingler method and white fiber dissections were performed. RESULTS: The insula is located entirely inside the Sylvian fissure. The topographic hemispheric anatomy, Sylvian fissure, opercula, surrounding sulci and gyri, as well as the M2, M3, and M4 segments were identified. The anatomy of the insula, with the sulci and gyri and the limiting sulci, were also identified and described. The main white matter fiber tracts of the operculoinsular compartments of the Sylvian fissure as well as the main association and commissural fibers located deep in the insula were dissected and demonstrated. CONCLUSIONS: Complementing topographic anatomy with detailed study of white matter fibers and their integration can help the neurosurgeon to safely approach lesions in the insular region, improving postoperative results in the microsurgical treatment of aneurysmal lesions, insular tumors, or epilepsy surgery.

Disinfection performance using a UV/persulfate system: effects derived from different aqueous matrices.

The development of advanced photochemical processes has experienced the emergence of a promising alternative for water disinfection, different from traditional methods. The applicability has primarily been investigated in drinking and wastewater; however, new challenges related to microbiological control in marine waters necessitate evaluating the applicability of this process in such water matrices. In this study, the efficacy of persulfate (PDS) activated with UV-light against E. faecalis has been tested on the bench scale. Firstly, optimization of the different PDS concentrations (1-10 mM) and exposure times (0-5 min) was performed in distilled water. 1 mM of PDS was selected as the best dosage within the range tested. Secondly, in order to evaluate the effects of different inorganic compounds usually found in natural waters, the efficiency of the UV/PDS system was tested in three different matrices: mineral water, saltwater, and marine saltwater. Finally, different bacteria were evaluated in consortium (E. coli + E. faecalis), suggesting the same inactivation level independently on the bacterial groups and structures. The results suggest that PDS is an attractive alternative to other photochemical processes currently in use for seawater treatment and this application deserved further research.

Risks of Preterm Premature Rupture of Membranes and Preterm Birth Post Fetoscopy Based on Location of Trocar Insertion Site.

OBJECTIVE: The objective of this study was to assess whether the location of the trocar insertion site for laser treatment of twin-twin transfusion syndrome was associated with preterm-premature rupture of membranes (PPROM) and preterm birth (PTB). STUDY DESIGN: In this study trocar location was documented in the operating room. Lower uterine segment (LUS) location was defined as any insertion <10 cm vertically from the pubic symphysis. Lateral location was defined as ≥5 cm horizontally from the midline. Patient characteristics were tested against three outcomes: PPROM ≤ 21 days postoperative, PTB < 28 weeks, and PTB < 32 weeks. For each outcome, multiple logistic models were fitted to examine the effect of trocar location, controlling for potential risk factors. RESULTS: A total of 743 patients were studied. Patients with LUS location were twice as likely as those with a more superior location to have PPROM ≤ 21 days (OR = 2.33, 1.12-4.83, p = 0.0236). Patients with both a LUS and Lateral location were over six times more likely to have PPROM ≤ 21 days (OR = 6.66, 2.36-18.78, p = 0.0003). Trocar insertion site was not associated with PTB. CONCLUSION: We found that trocar insertion in the LUS, particularly the lateral LUS, was associated with an increased risk of PPROM.

Risk factors for fetomaternal bleeding after laser therapy for twin-twin transfusion syndrome.

OBJECTIVE: To quantify and assess potential risk factors for transplacental passage of fetal red blood cells (RBCs) into the maternal circulation (fetomaternal bleeding, FMB) after laser surgery for twin-twin transfusion syndrome (TTTS). STUDY DESIGN: A retrospective study of Rhesus-D negative patients that underwent laser surgery for TTTS. Patients with and without postoperative detectable fetal RBCs on Kleihauer-Betke (KB) testing were compared to determine risk factors for FMB. Patients were further sub-classified into those with a FMB < 20% and ≥20% of estimated fetoplacental blood volume. RESULTS: Of 60 studied patients, 26/60 (43%) had a positive postoperative KB test. The median fetal:adult RBC ratio was 0.00125, estimated to be a FMB volume of 6.25 mL. There were 17/26 (65%) of patients with FMB < 20% and 9/26 (35%) patients with ≥20% of the fetoplacental blood volume. Stage III-Recipient and III-Recipient/Donor patients were more likely to have a positive KB test (14/21 [66.7%] vs 12/39 [30.8%], OR = 4.50 [1.27-16.54], P = 0.0162). No other risk factors for FMB were apparent. CONCLUSIONS: Fetomaternal bleed appears to be a common finding after laser surgery for TTTS. TTTS Stage, particularly stage III-Recipient and III-Recipient/Donor, appears to be a risk factor for FMB.

Amniopatch treatment of iatrogenic preterm premature rupture of membranes (iPPROM) after fetoscopic laser surgery for twin-twin transfusion syndrome.

OBJECTIVES: Amniopatch is a proposed treatment of iatrogenic preterm premature rupture of membranes (iPPROM). We studied characteristics associated with successful amniopatch treatment of iPPROM after fetoscopic laser surgery for twin-twin transfusion syndrome. METHODS: Patients with iPPROM within 15 days of laser surgery treated with an amniopatch were studied. Factors associated with amniopatch success (i.e. cessation of leakage with normalization of amniotic fluid volume) were tested univariately and in multivariate logistic regression models. Continuous variables are expressed as median (range). RESULTS: Of 1124 patients undergoing laser surgery, 19 (1.7%) had iPPROM and subsequent amniopatch. Twelve (63.2%) were successful. Latency in days from iPPROM to delivery was greater in the successful group (114.0 [87.0-141.0]) versus (44.0 [3.9-88.0], p = 0.0005), which translated into greater gestational age (GA) (weeks) at delivery (35.1 [30.9-39.4] versus 28.1 [22.0-31.0], p = 0.0005). The 30-day survival of the affected recipient twin was improved (100% versus 57.1%, p = 0.0361). After multivariate testing, GA < 20 weeks at the time of the amniopatch placement was the only variable that remained associated with successful sealing of the membranes. CONCLUSIONS: Treatment of iPPROM via amniopatch was successful in almost two-thirds of cases and was associated with higher GA at delivery and improved perinatal survival.

Twin-to-Twin Transfusion Syndrome: Definition, Staging, and Ultrasound Assessment.

OBJECTIVE: The purpose of this article is to review the definition of twin-to-twin transfusion syndrome (TTTS) and the sonographic diagnostic assessment of these cases prior to therapy. MATERIALS AND METHODS: The article addresses the terminology used to refer to the condition and describes the systematic ultrasound assessment of the condition, including the ultrasound diagnosis, the staging of the disease, cervical assessment and pre-operative mapping. RESULTS: From an etymologic and medical point of view, the term 'fetofetal transfusion' is more appropriate than 'TTTS'. However, as the latter, and its attendant acronym TTTS, have been widely adopted in the English language, it is impractical to change at this point. TTTS is defined sonographically in the combined presence of a maximum vertical pocket (MVP) of 8 cm or greater in one sac and 2 cm or less in the other sac, regardless of the gestational age at diagnosis. Staging of the condition using the Quintero staging system is practical, reproducible, and accepted. Transvaginal cervical length assessment should be an integral part of the ultrasound evaluation. Pre-operative mapping to anticipate the location of the placental vascular anastomoses and avoid injuring the dividing membrane is also discussed. CONCLUSIONS: The term 'TTTS' can continue to be used in the English medical literature. The condition can be diagnosed and assessed following a systematic ultrasound methodology. The use of such ultrasound methodology breaks the examination into a distinct set of components, assuring a comprehensive examination and proper communication among caregivers.

Laser Treatment of Twin-to-Twin Transfusion Syndrome.

OBJECTIVE: Laser ablation of all placental vascular anastomoses is the optimal treatment for twin-twin transfusion syndrome (TTTS). However, two important controversies are apparent in the literature: (a) a gap between concept and performance, and (b) controversy regarding whether all the anastomoses can be identified endoscopically and whether blind lasering of healthy placenta is justified. The purpose of this article is: (a) to address the potential source of the gap between concept and performance by analyzing the fundamental steps needed to successfully accomplish the surgery, and (b) to discuss the resulting competency benchmarks reported with the different surgical techniques. MATERIALS AND METHODS: Laser surgery for TTTS can be broken down into two fundamental steps: (1) endoscopic identification of the placental vascular anastomoses, (2) laser ablation of the anastomoses. The two steps are not synonymous: (a) regarding the endoscopic identification of the anastomoses, the non-selective technique is based upon lasering all vessels crossing the dividing membrane, whether anastomotic or not. The selective technique identifies and lasers only placental vascular anastomoses. The Solomon technique is based on the theory that not all anastomoses are endoscopically visible and thus involves lasering healthy areas of the placenta between lasered anastomoses, (b) regarding the actual laser ablation of the anastomoses, successful completion of the surgery (i.e., lasering all the anastomoses) can be measured by the rate of persistent or reverse TTTS (PRTTTS) and how often a selective technique can be achieved. Articles representing the different techniques are discussed. RESULTS: The non-selective technique is associated with the lowest double survival rate (35%), compared with 60-75% of the Solomon or the Quintero selective techniques. The Solomon technique is associated with a 20% rate of residual patent placental vascular anastomoses, compared to 3.5-5% for the selective technique (p < .05). Both the Solomon and the selective technique are associated with a 1% risk of PRTTTS. Adequate placental assessment is highest with the selective technique (99%) compared with the Solomon (80%) or the 'standard' (60%) techniques (p < .05). A surgical performance index is proposed. CONCLUSION: The Quintero selective technique was associated with the highest rate of successful ablation and lowest rate of PRTTTS. The Solomon technique represents a historical backward movement in the identification of placental vascular anastomoses and is associated with higher rate of residual patent vascular communications. The reported outcomes of the Quintero selective technique do not lend support to the existence of invisible anastomoses or justify lasering healthy placental tissue.

Decreased Total Placental Mass Found in Twin-Twin Transfusion Syndrome Gestations with Selective Growth Restriction.

INTRODUCTION: We examined placental weight characteristics associated with donor selective intrauterine growth restriction (SIUGR) among patients with twin-twin transfusion syndrome (TTTS) who underwent laser surgery. MATERIALS AND METHODS: Fresh placental specimens were studied. Pregnancies with higher-order multiples, fetal demise, or disrupted or nonsubmitted placental specimens were excluded. Placental characteristics prospectively collected included total placental weight, individual placental weight, and placental share. Data were compared between pregnancies with SIUGR (TTTS + SIUGR group) and those without SIUGR (TTTS-only group). RESULTS: Of 369 consecutive patients who underwent laser surgery for TTTS, 155 (42%) met inclusion criteria: 91 with TTTS + SIUGR and 64 with TTTS-only. Compared to the TTTS-only group, patients in the TTTS + SIUGR group had a lower total placental weight (608 ± 163 vs. 687 ± 224 g, p = 0.012), with a lower donor individual placental weight (237 ± 91 vs. 291 ± 124 g, p = 0.002), but no apparent difference in the individual placental weight of recipient twins (371 ± 109 vs. 396 ± 133 g, p = 0.211). Donor placental share was smaller in those pregnancies affected by SIUGR (38.7 ± 9.6 vs. 42.3 ± 9.8%, p = 0.029). DISCUSSION: TTTS patients with SIUGR had a lower total placental weight and a lower donor individual placental weight compared to those without SIUGR. These findings suggest that differences in donor individual placental weights for SIUGR gestations may not solely be related to differences in placental share.