Recurrent Cesarean scar pregnancy: case series and literature review

OBJECTIVES

To determine the rate of recurrent Cesarean scar pregnancy (CSP) in our clinical practices and to evaluate whether the mode of treatment of a CSP is associated with the risk of recurrent CSP, as well as to review the published literature on recurrent CSP.

METHODS

We performed a retrospective search of our six obstetric and gynecological departmental ultrasound databases for all CSPs and recurrent CSPs between 2010 and 2019. We extracted various data, including number of CSPs with follow-up, number of cases attempting and number achieving pregnancy following treatment of CSP and number of recurrent CSPs, as well as details of the treatment of the original CSP. After analyzing the clinical data, we evaluated whether the mode of treatment terminating the previous CSP was associated with the risk of recurrent CSP. We also performed a PubMed search for: 'recurrent Cesarean scar pregnancy' and 'recurrent Cesarean scar ectopic pregnancy'. Articles were reviewed for year of publication, and extraction and analysis of the same data as those obtained from our departmental databases were performed.

RESULTS

Our database search identified 252 cases of CSP. The overall rate of clinical follow-up ranged between 71.4% and 100%, according to treatment site (mean, 90.9%). Among these, 105 women had another pregnancy after treatment of the previous CSP. Of these, 36 (34.3%) pregnancies were recurrent CSP, with 27 women having a single recurrence and three women having multiple recurrences, one with two, one with three and one with four. We did not find any particular single or combination treatment mode terminating the previous CSP to be associated with recurrent CSP. The literature search identified 17 articles that yielded sufficient information for us to evaluate their reported prevalence of recurrent CSP. These reported 1743 primary diagnoses of CSP, of which 944 had reliable follow-up. Data were available for 489 cases that attempted to conceive again after treatment of a previous CSP, and on the 327 pregnancies achieved. Of these, 67 (20.5%) were recurrent CSP.

CONCLUSIONS

On the basis of our pooled clinical data and review of the literature, recurrent CSP is apparently more common than was previously assumed based upon mostly single-case reports or series with few cases. This should be borne in mind when counseling patients undergoing treatment for CSP regarding their risk of recurrence. We found no obvious causal relationship or association between the type of treatment of the previous CSP and recurrence of CSP. Patients who become pregnant after treatment of a CSP should be encouraged to have an early (5-7-week) first-trimester transvaginal scan to determine the location of the gestation. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Value of first-trimester ultrasound in prediction of third-trimester sonographic stage of placenta accreta spectrum disorder and surgical outcome

OBJECTIVES

To explore whether early first-trimester ultrasound can predict the third-trimester sonographic stage of placenta accreta spectrum (PAS) disorder and to elucidate whether combining first-trimester ultrasound findings with the sonographic stage of PAS disorder can stratify the risk of adverse surgical outcome in women at risk for PAS disorder.

METHODS

This was a retrospective analysis of prospectively collected data from women with placenta previa, and at least one previous Cesarean delivery (CD) or uterine surgery, for whom early first-trimester (5-7 weeks' gestation) ultrasound images could be retrieved. The relationship between the position of the gestational sac and the prior CD scar was assessed using three sonographic markers for first-trimester assessment of Cesarean scar (CS) pregnancy, reported by Calí et al. (crossover sign (COS)), Kaelin Agten et al. (implantation of the gestational sac on the scar vs in the niche of the CS) and Timor-Tritsch et al. (position of the center of the gestational sac below vs above the midline of the uterus), by two different examiners blinded to the final diagnosis and clinical outcome. The primary aim of the study was to explore the association between first-trimester ultrasound findings and the stage of PAS disorder on third-trimester ultrasound. Our secondary aim was to elucidate whether the combination of first-trimester ultrasound findings and sonographic stage of PAS disorder can predict surgical outcome. Logistic regression analysis and area under the receiver-operating-characteristics curve (AUC) were used to analyze the data.

RESULTS

One hundred and eighty-seven women with vasa previa were included. In this cohort, 79.6% (95% CI, 67.1-88.2%) of women classified as COS-1, 94.4% (95% CI, 84.9-98.1%) of those with gestational-sac implantation in the niche of the prior CS and 100% (95% CI, 93.4-100%) of those with gestational sac located below the uterine midline, on first-trimester ultrasound, were affected by the severest form of PAS disorder (PAS3) on third-trimester ultrasound. On multivariate logistic regression analysis, COS-1 (odds ratio (OR), 7.9 (95% CI, 4.0-15.5); P < 0.001), implantation of the gestational sac in the niche (OR, 29.1 (95% CI, 8.1-104); P < 0.001) and location of the gestational sac below the midline of the uterus (OR, 38.1 (95% CI, 12.0-121); P < 0.001) were associated independently with PAS3, whereas parity (P = 0.4) and the number of prior CDs (P = 0.5) were not. When translating these figures into diagnostic models, first-trimester diagnosis of COS-1 (AUC, 0.94 (95% CI, 0.91-0.97)), pregnancy implantation in the niche (AUC, 0.92 (95% CI, 0.89-0.96)) and gestational sac below the uterine midline (AUC, 0.92 (95% CI, 0.88-0.96)) had a high predictive accuracy for PAS3. There was an adverse surgical outcome in 22/187 pregnancies and it was more common in women with, compared to those without, COS-1 (P < 0.001), gestational-sac implantation in the niche (P < 0.001) and gestational-sac position below the uterine midline (P < 0.001). On multivariate logistic regression analysis, third-trimester ultrasound diagnosis of PAS3 (OR, 4.3 (95% CI, 2.1-17.3)) and first-trimester diagnosis of COS-1 (OR, 7.9 (95% CI, 4.0-15.5); P < 0.001), pregnancy implantation in the niche (OR, 29.1 (95% CI, 8.1-79.0); P < 0.001) and position of the sac below the uterine midline (OR, 6.6 (95% CI, 3.9-16.2); P < 0.001) were associated independently with adverse surgical outcome. When combining the sonographic coordinates of the three first-trimester imaging markers, we identified an area we call high-risk-for-PAS triangle, which may enable an easy visual perception and application of the three methods to prognosticate the risk for CS pregnancy and PAS disorder, although it requires validation in large prospective studies.

CONCLUSIONS

Early first-trimester sonographic assessment of pregnancies with previous CD can predict reliably ultrasound stage of PAS disorder. Combination of findings on first-trimester ultrasound with second- and third-trimester ultrasound examination can stratify the surgical risk in women affected by a PAS disorder. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

New sonographic marker of borderline ovarian tumor: microcystic pattern of papillae and solid components

OBJECTIVE

To describe and evaluate the utility of a new sonographic microcystic pattern, which is typical of borderline ovarian tumor (BOT) papillary projections, solid component(s) and/or septa, as a new ultrasound marker that is capable of distinguishing BOT from other adnexal masses, and to present/obtain histologic confirmation.

METHODS

In this retrospective study, we identified women with a histologic diagnosis of BOT following surgical resection who had undergone preoperative transvaginal ultrasound (TVS) examination. All images were reviewed for presence or absence of thin-walled, fluid-filled cluster(s) of 1-3-mm cystic formations, associated with solid component(s), papillary projections and/or septa. From the same cases, histopathologic slides of each BOT were examined for presence of any of these microcystic features which had been identified on TVS. To confirm that the microcystic TVS pattern is unique to BOTs, we also selected randomly from our ultrasound and surgical database 20 cases of epithelial ovarian cancer and 20 cases of benign cystadenoma, for review by the same pathologists. To confirm the novelty of our findings, we searched PubMed for literature published in the English language between 2010 and 2018 to determine whether the association between microcystic tissue pattern and BOT has been described previously.

RESULTS

Included in the final analysis were 62 patients (67 ovaries) with preoperative TVS and surgically confirmed BOT on pathologic examination. The mean patient age at surgery was 39.8 years. The mean BOT size at TVS was 60.7 mm. Of the 67 BOTs, 47 (70.1%) were serous, 15 (22.4%) were mucinous and five (7.5%) were seromucinous. We observed on TVS a microcystic pattern in the papillary projections, solid component(s) and/or septa in 60 (89.6%) of the 67 BOTs, including 46 (97.9%) of the 47 serous BOTs, 11 (73.3%) of the 15 mucinous BOTs and three (60.0%) of the five seromucinous BOTs. On microscopic evaluation, 60 (89.6%) of the 67 samples had characteristic 1-3-mm fluid-filled cysts similar to those seen on TVS. In seven cases there was a discrepancy between sonographic and histologic observation of a microcystic pattern. The 20 cystadenomas were mostly unilocular and/or multilocular and largely avascular. None of them or the 20 epithelial ovarian malignancies displayed microcystic characteristics, either on TVS or at histology. On review of 23 published articles in the English medical literature, containing 163 sonographic images of BOT, we found that, while all images contained it, there was no description of the microcystic tissue pattern.

CONCLUSION

We report herein a novel sonographic marker of BOT, a 'microcystic pattern' of BOT papillary projections, solid component(s) and/or septa. This was seen in the majority of both serous and mucinous BOT cases. Importantly, based on comparison of sonographic images and histopathology of benign entities and malignancies, the microcystic appearance seems to be unique to BOTs. No similar description has been published previously. Utilization of this new marker should help to identify BOT correctly, discriminating it from ovarian cancer and benign ovarian pathology, and should ensure appropriate clinical and surgical management. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

First-trimester detection of abnormally invasive placenta in high-risk women: systematic review and meta-analysis

OBJECTIVES

The primary aim of this systematic review was to ascertain whether ultrasound signs suggestive of abnormally invasive placenta (AIP) are present in the first trimester of pregnancy. Secondary aims were to ascertain the strength of association and the predictive accuracy of such signs in detecting AIP in the first trimester.

METHODS

An electronic search of MEDLINE, EMBASE, CINAHL and Cochrane databases (2000-2016) was performed. Only studies reporting on first-trimester diagnosis of AIP that was subsequently confirmed in the third trimester either during operative delivery or by pathological examination were included. Meta-analysis of proportions, random-effects meta-analysis and hierarchical summary receiver-operating characteristics curve analysis were used to analyze the data.

RESULTS

Seven studies, involving 551 pregnancies at high risk of AIP, were included. At least one ultrasound sign suggestive of AIP was detected in 91.4% (95% CI, 85.8-95.7%) of cases with confirmed AIP. The most common ultrasound feature in the first trimester of pregnancy was low implantation of the gestational sac close to a previous uterine scar, which was observed in 82.4% (95% CI, 46.6-99.8%) of cases. Anechoic spaces within the placental mass (lacunae) were observed in 46.0% (95% CI, 10.9-83.7%) and a reduced myometrial thickness in 66.8% (95% CI, 45.2-85.2%) of cases affected by AIP. Pregnancies with a low implantation of the gestational sac had a significantly higher risk of AIP (odds ratio, 19.6 (95% CI, 6.7-57.3)), with a sensitivity and specificity of 44.4% (95% CI, 21.5-69.2%) and 93.4% (95% CI, 90.5-95.7%), respectively.

CONCLUSIONS

Ultrasound signs of AIP can be present during the first trimester of pregnancy, even before 11 weeks' gestation. Low anterior implantation of the placenta/gestational sac close to or within the scar was the most commonly seen early ultrasound sign suggestive of AIP, although its individual predictive accuracy was not high. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Maximising Synergy among Tropical Plant Systematists, Ecologists, and Evolutionary Biologists

Closer collaboration among ecologists, systematists, and evolutionary biologists working in tropical forests, centred on studies within long-term permanent plots, would be highly beneficial for their respective fields. With a key unifying theme of the importance of vouchered collection and precise identification of species, especially rare ones, we identify four priority areas where improving links between these communities could achieve significant progress in biodiversity and conservation science: (i) increasing the pace of species discovery; (ii) documenting species turnover across space and time; (iii) improving models of ecosystem change; and (iv) understanding the evolutionary assembly of communities and biomes.

Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models

Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs.

Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models

Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs.

Consistent, small effects of treefall disturbances on the composition and diversity of four Amazonian forests

Understanding the resilience of moist tropical forests to treefall disturbance events is important for understanding the mechanisms that underlie species coexistence and for predicting the future composition of these ecosystems. Here, we test whether variation in the functional composition of Amazonian forests determines their resilience to disturbance.We studied the legacy of natural treefall disturbance events in four forests across Amazonia that differ substantially in functional composition. We compared the composition and diversity of all free-standing woody stems 2-10 cm diameter in previously disturbed and undisturbed 20 × 20 m subplots within 55, one-hectare, long-term forest inventory plots.Overall, stem number increased following disturbance, and species and functional composition shifted to favour light-wooded, small-seeded taxa. Alpha-diversity increased, but beta-diversity was unaffected by disturbance, in all four forests.Changes in response to disturbance in both functional composition and alpha-diversity were, however, small (2 - 4% depending on the parameter) and similar among forests. Synthesis. This study demonstrates that variation in the functional composition of Amazonian forests does not lead to large differences in the response of these forests to treefall disturbances, and overall, these events have a minor role in maintaining the diversity of these ecosystems.

Consistent, small effects of treefall disturbances on the composition and diversity of four Amazonian forests

Understanding the resilience of moist tropical forests to treefall disturbance events is important for understanding the mechanisms that underlie species coexistence and for predicting the future composition of these ecosystems. Here, we test whether variation in the functional composition of Amazonian forests determines their resilience to disturbance.We studied the legacy of natural treefall disturbance events in four forests across Amazonia that differ substantially in functional composition. We compared the composition and diversity of all free-standing woody stems 2-10 cm diameter in previously disturbed and undisturbed 20 × 20 m subplots within 55, one-hectare, long-term forest inventory plots.Overall, stem number increased following disturbance, and species and functional composition shifted to favour light-wooded, small-seeded taxa. Alpha-diversity increased, but beta-diversity was unaffected by disturbance, in all four forests.Changes in response to disturbance in both functional composition and alpha-diversity were, however, small (2 - 4% depending on the parameter) and similar among forests. Synthesis. This study demonstrates that variation in the functional composition of Amazonian forests does not lead to large differences in the response of these forests to treefall disturbances, and overall, these events have a minor role in maintaining the diversity of these ecosystems.

Foley balloon catheter to prevent or manage bleeding during treatment for cervical and Cesarean scar pregnancy

OBJECTIVE

To demonstrate the efficacy of placement and inflation of Foley balloon catheters prophylactically to prevent, or as an adjuvant therapy to control, bleeding in women undergoing treatment for Cesarean scar pregnancy (CSP) or cervical pregnancy (CxP).

METHODS

This was a retrospective study of 18 women with either CSP (n = 16) or CxP (n = 2), who underwent Foley balloon catheter placement under continuous transvaginal or transabdominal ultrasound guidance to prevent or manage bleeding following treatment, which in most cases comprised local (intragestational sac) and intramuscular (IM) methotrexate (MTX) injections. In eight cases, the balloon catheter was placed immediately following local and/or IM MTX treatment, either because of bleeding or prophylactically; in eight cases, the catheter was placed as part of a two-step protocol, with patients first treated with local and IM MTX injection, then suction aspiration on Day 4 or 5, followed by planned insertion of a balloon catheter; in one patient the balloon was placed on Day 21 after local and IM MTX treatment, due to sudden bleeding; and in one case of a heterotopic pregnancy, one intrauterine and one cervical, the balloon was placed due to severe bleeding. Human chorionic gonadotropin (hCG) levels were evaluated weekly following MTX injection.

RESULTS

Gestational ages at balloon placement ranged between 5 and 12 + 2 weeks. All embryos/fetuses, with the exception of the cervical heterotopic one, had heart activity and catheter placement was well-tolerated by all women. The balloon tamponade effectively reduced or prevented maternal vaginal bleeding in all except one patient; this woman had a heterotopic CxP and required abdominal robotic cerclage to control the bleeding. Catheters were kept in place for a mean of 3.6 (range, 1-6) days. hCG levels returned to low or zero levels within 19-82 days following MTX injection. Fifteen women required antibiotic treatment following the procedure. One woman with CSP developed an arteriovenous malformation requiring uterine artery embolization.

CONCLUSION

Ultrasound-guided placement and inflation of Foley balloon catheters was easy to perform and well-tolerated by patients undergoing treatment for CSP or CxP, and successfully prevented or helped in the management of bleeding complications. Based on our experience and previous publications we suggest having the option of balloon catheter insertion available when local treatment of CSP or CxP is undertaken.

Cesarean scar pregnancy is a precursor of morbidly adherent placenta

OBJECTIVE

To provide further sonographic, clinical and histological evidence that Cesarean scar pregnancy (CSP) is a precursor to and an early form of second- and third-trimester morbidly adherent placenta (MAP).

METHODS

This is a report of 10 cases of CSP identified early, in which the patients decided to continue the pregnancy, following counseling that emphasized the possibility of both significant pregnancy complications and a need for hysterectomy. Pregnancies were followed at 2-4-week intervals with ultrasound scans and customary monitoring. The aim was for patients to reach near term or term and then undergo elective Cesarean delivery and, if necessary, hysterectomy. Charts, ultrasound images, operative reports and histopathological examinations of the placentae were reviewed.

RESULTS

The ultrasound diagnosis of CSP was made before 10 weeks. By the second trimester, all patients exhibited sonographic signs of MAP. Nine of the 10 patients delivered liveborn neonates between 32 and 37 weeks. In the tenth pregnancy, progressive shortening of the cervix and intractable vaginal bleeding prompted termination, with hysterectomy, at 20 weeks. Two other patients in the cohort had antepartum complications (bleeding at 33 weeks in one case and contractions at 32 weeks in the other). All patients underwent hysterectomy at the time of Cesarean delivery, with total blood loss ranging from 300 to 6000 mL. Placenta percreta was the histopathological diagnosis in all 10 cases.

CONCLUSION

The cases in this series validate the hypothesis that CSP is a precursor of MAP, both sharing the same histopathology. Our findings provide evidence that can be used to counsel patients with CSP, to enable them to make an informed choice between first-trimester termination and continuation of the pregnancy, with its risk of premature delivery and loss of uterus and fertility.

Markedly divergent estimates of Amazon forest carbon density from ground plots and satellites

AIM

The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directly, and thus may miss significant spatial variations in forest structure. We test the stated accuracy of pantropical carbon maps using a large independent field dataset.

LOCATION

Tropical forests of the Amazon basin. The permanent archive of the field plot data can be accessed at: http://dx.doi.org/10.5521/FORESTPLOTS.NET/2014_1.

METHODS

Two recent pantropical RS maps of vegetation carbon are compared to a unique ground-plot dataset, involving tree measurements in 413 large inventory plots located in nine countries. The RS maps were compared directly to field plots, and kriging of the field data was used to allow area-based comparisons.

RESULTS

The two RS carbon maps fail to capture the main gradient in Amazon forest carbon detected using 413 ground plots, from the densely wooded tall forests of the north-east, to the light-wooded, shorter forests of the south-west. The differences between plots and RS maps far exceed the uncertainties given in these studies, with whole regions over- or under-estimated by > 25%, whereas regional uncertainties for the maps were reported to be < 5%.

MAIN CONCLUSIONS

Pantropical biomass maps are widely used by governments and by projects aiming to reduce deforestation using carbon offsets, but may have significant regional biases. Carbon-mapping techniques must be revised to account for the known ecological variation in tree wood density and allometry to create maps suitable for carbon accounting. The use of single relationships between tree canopy height and above-ground biomass inevitably yields large, spatially correlated errors. This presents a significant challenge to both the forest conservation and remote sensing communities, because neither wood density nor species assemblages can be reliably mapped from space.

Cesarean scar pregnancy and early placenta accreta share common histology

OBJECTIVE

To determine, by evaluation of histological slides, images and descriptions of early (second-trimester) placenta accreta (EPA) and placental implantation in cases of Cesarean scar pregnancy (CSP), whether these are pathologically indistinguishable and whether they both represent different stages in the disease continuum leading to morbidly adherent placenta in the third trimester.

METHODS

The database of a previously published review of CSP and EPA was used to identify articles with histopathological descriptions and electronic images for pathological review. When possible, microscopic slides and/or paraffin blocks were obtained from the original researchers. We also included from our own institutions cases of CSP and EPA for which pathology specimens were available. Two pathologists examined all the material independently and, blinded to each other's findings, provided a pathological diagnosis based on microscopic appearance. Interobserver agreement in diagnosis was determined.

RESULTS

Forty articles were identified, which included 31 cases of CSP and 13 cases of EPA containing histopathological descriptions and/or images of the pathology. We additionally included six cases of CSP and eight cases of EPA from our own institutions, giving a total of 58 cases available for histological evaluation (37 CSP and 21 EPA) containing clear definitions of morbidly adherent placenta. In the 29 cases for which images/slides were available for histopathological evaluation, both pathologists attested to the various degrees of myometrial and/or scar tissue invasion by placental villi with scant or no intervening decidua, consistent with the classic definition of morbidly adherent placenta. Based on the reviewed material, cases with a diagnosis of EPA and those with a diagnosis of CSP showed identical histopathological features. Interobserver correlation was high (kappa = 0.93).

CONCLUSIONS

EPA and placental implantation in CSP are histopathologically indistinguishable and may represent different stages in the disease continuum leading to morbidly adherent placenta in the third trimester.

Hyperdominance in the Amazonian tree flora

The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees. Most of these are habitat specialists and only dominant in one or two regions of the basin. We discuss some implications of the finding that a small group of species--less diverse than the North American tree flora--accounts for half of the world's most diverse tree community.

Prenatal diagnosis of unilateral proximal femoral focal deficiency at 19 weeks' gestation: case report and review of the literature

Proximal femoral focal deficiency (PFFD) represents a rare and complex deformity manifested by hypoplasia of a variable portion of the femur with shortening of the entire limb. The condition may be unilateral or bilateral and is often associated with other congenital anomalies. Recent technological advances in ultrasound imaging offer the opportunity to detect an increasing number of rare skeletal malformation syndromes whose correct diagnosis is essential for adequate counseling and management of the pregnancy. We report a case of fetal non-familial PFFD diagnosed prenatally using two-dimensional and three-dimensional images. Clinical findings, differential diagnosis and management of this rare skeletal dysplasia are discussed and a review of the recent literature is given.

Severe sorafenib-induced hand-foot skin reaction

Sorafenib is a new drug, multikinase inhibitor, which has been recently approved for the treatment of metastatic renal cell carcinoma and hepatocellular carcinoma. Up to 90 percent of patients receiving this drug have been reported to develop dermatological symptoms. Recently, it has been suggested that the appearance of skin toxicity during therapy may indicate antitumor activity. We report a new case of sorafenib-induced severe hand-foot skin reaction, which hindered the patient's normal life. The reaction was successfully treated with topical costicosteroids and discontinuation of sorafenib. However, the patient died one month later.

Drought-mortality relationships for tropical forests

*The rich ecology of tropical forests is intimately tied to their moisture status. Multi-site syntheses can provide a macro-scale view of these linkages and their susceptibility to changing climates. Here, we report pan-tropical and regional-scale analyses of tree vulnerability to drought. *We assembled available data on tropical forest tree stem mortality before, during, and after recent drought events, from 119 monitoring plots in 10 countries concentrated in Amazonia and Borneo. *In most sites, larger trees are disproportionately at risk. At least within Amazonia, low wood density trees are also at greater risk of drought-associated mortality, independent of size. For comparable drought intensities, trees in Borneo are more vulnerable than trees in the Amazon. There is some evidence for lagged impacts of drought, with mortality rates remaining elevated 2 yr after the meteorological event is over. *These findings indicate that repeated droughts would shift the functional composition of tropical forests toward smaller, denser-wooded trees. At very high drought intensities, the linear relationship between tree mortality and moisture stress apparently breaks down, suggesting the existence of moisture stress thresholds beyond which some tropical forests would suffer catastrophic tree mortality.

Basic as well as detailed neurosonograms can be performed by offline analysis of three-dimensional fetal brain volumes

OBJECTIVES

To evaluate the feasibility and the processing time of offline analysis of three-dimensional (3D) brain volumes to perform a basic, as well as a detailed, targeted, fetal neurosonogram.

METHODS

3D fetal brain volumes were obtained in 103 consecutive healthy fetuses that underwent routine anatomical survey at 20-23 postmenstrual weeks. Transabdominal gray-scale and power Doppler volumes of the fetal brain were acquired by one of three experienced sonographers (an average of seven volumes per fetus). Acquisition was first attempted in the sagittal and coronal planes. When the fetal position did not enable easy and rapid access to these planes, axial acquisition at the level of the biparietal diameter was performed. Offline analysis of each volume was performed by two of the authors in a blinded manner. A systematic technique of 'volume manipulation' was used to identify a list of 25 brain dimensions/structures comprising a complete basic evaluation, intracranial biometry and a detailed targeted fetal neurosonogram. The feasibility and reproducibility of obtaining diagnostic-quality images of the different structures was evaluated, and processing times were recorded, by the two examiners.

RESULTS

Diagnostic-quality visualization was feasible in all of the 25 structures, with an excellent visualization rate (85-100%) reported in 18 structures, a good visualization rate (69-97%) reported in five structures and a low visualization rate (38-54%) reported in two structures, by the two examiners. An average of 4.3 and 5.4 volumes were used to complete the examination by the two examiners, with a mean processing time of 7.2 and 8.8 minutes, respectively. The overall agreement rate for diagnostic visualization of the different brain structures between the two examiners was 89.9%, with a kappa coefficient of 0.5 (P < 0.001).

CONCLUSIONS

In experienced hands, offline analysis of 3D brain volumes is a reproducible modality that can identify all structures necessary to complete both a basic and a detailed second-trimester fetal neurosonogram.

Drought sensitivity of the Amazon rainforest

Amazon forests are a key but poorly understood component of the global carbon cycle. If, as anticipated, they dry this century, they might accelerate climate change through carbon losses and changed surface energy balances. We used records from multiple long-term monitoring plots across Amazonia to assess forest responses to the intense 2005 drought, a possible analog of future events. Affected forest lost biomass, reversing a large long-term carbon sink, with the greatest impacts observed where the dry season was unusually intense. Relative to pre-2005 conditions, forest subjected to a 100-millimeter increase in water deficit lost 5.3 megagrams of aboveground biomass of carbon per hectare. The drought had a total biomass carbon impact of 1.2 to 1.6 petagrams (1.2 x 10(15) to 1.6 x 10(15) grams). Amazon forests therefore appear vulnerable to increasing moisture stress, with the potential for large carbon losses to exert feedback on climate change.

Three-dimensional inversion rendering in the first- and early second-trimester fetal brain: its use in holoprosencephaly

OBJECTIVES

To explore the feasibility and added value of three-dimensional (3D) inversion rendering of the developing embryonic/fetal ventricular system, and to apply this display technique to enhance the sonographic examination of holoprosencephaly.

METHODS

3D volumes of the embryonic/fetal brain were acquired from four normal fetuses at 8-11 postmenstrual weeks, and four fetuses diagnosed with holoprosencephaly between 9 and 14 postmenstrual weeks. The volumes were then analyzed offline to obtain inversion rendered 3D shapes of the ventricular systems.

RESULTS

All inversion rendering displays were successful and provided the opportunity to study normal as well as pathological aspects of the early fetal brain.

CONCLUSIONS

Inversion rendering of early fetal brain ventricles is feasible and should be attempted if additional information about the early normal or pathological fetal brain is needed. It may have scientific value in embryologic or genetic studies.

Maternal anxiety and ultrasound markers for aneuploidy in a multiethnic population

OBJECTIVE

Discussion of isolated ultrasound (US) markers for fetal aneuploidy can provoke significant patient anxiety. The objective of this study is to quantify maternal anxiety associated with the detection of these markers.

METHODS

All patients undergoing routine second-trimester US examination for fetal anatomical survey over a one-year period were administered the State-Trait Anxiety Inventory (STAI) for Adults before and after the procedure. Women with isolated fetal markers for aneuploidy were notified of the findings but discouraged from pursuing amniocentesis. Rates of normal US examination, aneuploidy markers, anomalies, amniocentesis, and pregnancy outcomes were assessed across the ethnic groups. Pre- and post-ultrasound STAI surveys were scored and standardized with previously established norms. Student t-tests, Chi-square, and analysis of variance (ANOVA) were used where appropriate.

RESULTS

Among the 798 patients tested, 57% were Hispanic, 30% were Asian, 6% were Black, and 7% were White. Maternal anxiety level was decreased in women after a normal US. The anxiety level increased with aneuploidy markers and was the highest with anomalies. Aneuploidy markers were more common among Hispanic and Asian fetuses, without any associated aneuploidy. Women with isolated aneuploidy markers underwent amniocentesis as often as women with advanced maternal age.

CONCLUSION

The detection and communication of isolated aneuploidy markers is associated with increased maternal anxiety and unnecessary amniocentesis.

Non-surgical management of live ectopic pregnancy with ultrasound-guided local injection: a case series

OBJECTIVES

To describe a series of consecutive cases of live ectopic pregnancies managed with ultrasound-guided local injection of methotrexate (MTX) or potassium chloride (KCl).

METHODS

Eighteen consecutive women with live and unruptured, tubal, cornual or cervical ectopic pregnancies referred to our unit for evaluation and management underwent risk-benefit counseling. Under transvaginal ultrasound guidance, puncture and injection of the ectopic pregnancy was performed using an automated puncture device. Either MTX or KCl was injected, producing immediate cessation of fetal cardiac activity.

RESULTS

Of the 18 ectopic pregnancies, 10 were cervical, four were tubal and four were cornual. The mean initial beta-hCG level was 33 412 IU and the mean gestational age was 6 + 6 weeks. Ten ectopic gestational sacs were injected with KCl and eight were injected with MTX. There was no difference in time to resolution of the ectopic pregnancies between those injected with KCl and those with MTX.

CONCLUSIONS

Unruptured live ectopic pregnancies of many types can be successfully managed without surgical intervention through local injection of KCl or MTX.

Simple ultrasound evaluation of the anal sphincter in female patients using a transvaginal transducer

OBJECTIVE

Fecal incontinence affects 0.2% of women aged 15-64 years and about 1.3% of women over 64 years. Most cases are related to instrumental deliveries affecting the anal sphincter complex. We propose a simple technique using the generally available transvaginal transducer to evaluate the anal sphincter complex.

METHODS

Ninety-two patients underwent ultrasound examination. Group I consisted of 53 nulliparous patients. In Group II there were six patients with normal spontaneous vaginal deliveries without episiotomies. In Group III there were 14 patients with vaginal deliveries and one to three episiotomies but no lacerations. In Group IV there were nine postpartum patients with recently repaired (48 h to 3 weeks) third- and fourth-degree lacerations. All women in Groups I-IV were asymptomatic. Group V consisted of 10 patients symptomatic for fecal incontinence. We used a vaginal probe (5-9-MHz) with the footprint placed in the fourchette pointing towards the anus in a transverse and then in a median (sagittal) plane. If seen, the combined internal and external anal sphincter thickness at the 12 o'clock location was measured. We visualized normal star-shaped mucosal folds on the transverse section and described the sonographic anatomy in both planes.

RESULTS

The mean sphincter thickness measured at 12 o'clock in Group I was 2.3 (range, 1.0-4.7) mm, in Group II it was 2.9 (range, 2.4-3.4) mm, and in Group III it was 2.3 (range, 1.0-3.7) mm. The differences between these three groups were not significant. Patients from Group IV showed thinning or discontinuous sphincter anatomy at the 12 o'clock position. All symptomatic patients from Group V showed abnormal sphincter anatomy, and the normal star-like appearance of the anal mucosa on the transverse section was deformed, radiating from the point of the sphincter damage. Four of the 10 patients in this group underwent surgical repair. In these patients the sonographic findings were confirmed.

CONCLUSIONS

The images obtained using this imaging modality show the sphincter muscle anatomy as well as the possible pathology. Due to its simplicity the technique can be applied in any place where a vaginal transducer is available.

Pattern and process in Amazon tree turnover, 1976-2001

Previous work has shown that tree turnover, tree biomass and large liana densities have increased in mature tropical forest plots in the late twentieth century. These results point to a concerted shift in forest ecological processes that may already be having significant impacts on terrestrial carbon stocks, fluxes and biodiversity. However, the findings have proved controversial, partly because a rather limited number of permanent plots have been monitored for rather short periods. The aim of this paper is to characterize regional-scale patterns of 'tree turnover' (the rate with which trees die and recruit into a population) by using improved datasets now available for Amazonia that span the past 25 years. Specifically, we assess whether concerted changes in turnover are occurring, and if so whether they are general throughout the Amazon or restricted to one region or environmental zone. In addition, we ask whether they are driven by changes in recruitment, mortality or both. We find that: (i) trees 10 cm or more in diameter recruit and die twice as fast on the richer soils of southern and western Amazonia than on the poorer soils of eastern and central Amazonia; (ii) turnover rates have increased throughout Amazonia over the past two decades; (iii) mortality and recruitment rates have both increased significantly in every region and environmental zone, with the exception of mortality in eastern Amazonia; (iv) recruitment rates have consistently exceeded mortality rates; (v) absolute increases in recruitment and mortality rates are greatest in western Amazonian sites; and (vi) mortality appears to be lagging recruitment at regional scales. These spatial patterns and temporal trends are not caused by obvious artefacts in the data or the analyses. The trends cannot be directly driven by a mortality driver (such as increased drought or fragmentation-related death) because the biomass in these forests has simultaneously increased. Our findings therefore indicate that long-acting and widespread environmental changes are stimulating the growth and productivity of Amazon forests.

Increasing biomass in Amazonian forest plots

A previous study by Phillips et al. of changes in the biomass of permanent sample plots in Amazonian forests was used to infer the presence of a regional carbon sink. However, these results generated a vigorous debate about sampling and methodological issues. Therefore we present a new analysis of biomass change in old-growth Amazonian forest plots using updated inventory data. We find that across 59 sites, the above-ground dry biomass in trees that are more than 10 cm in diameter (AGB) has increased since plot establishment by 1.22 +/- 0.43 Mg per hectare per year (ha(-1) yr(-1), where 1 ha = 10(4) m2), or 0.98 +/- 0.38 Mg ha(-1) yr(-1) if individual plot values are weighted by the number of hectare years of monitoring. This significant increase is neither confounded by spatial or temporal variation in wood specific gravity, nor dependent on the allometric equation used to estimate AGB. The conclusion is also robust to uncertainty about diameter measurements for problematic trees: for 34 plots in western Amazon forests a significant increase in AGB is found even with a conservative assumption of zero growth for all trees where diameter measurements were made using optical methods and/or growth rates needed to be estimated following fieldwork. Overall, our results suggest a slightly greater rate of net stand-level change than was reported by Phillips et al. Considering the spatial and temporal scale of sampling and associated studies showing increases in forest growth and stem turnover, the results presented here suggest that the total biomass of these plots has on average increased and that there has been a regional-scale carbon sink in old-growth Amazonian forests during the previous two decades.

First-trimester diagnosis of sacrococcygeal teratoma: the role of three-dimensional ultrasound

A fetus was suspected of having a sacrococcygeal teratoma (SCT) on routine nuchal translucency evaluation by sonography at 12+3 weeks. The patient was referred for three-dimensional (3D) sonography to further delineate the extent of the mass. In this case, real-time scanning of the mass in 3D mode assisted the diagnosis of the mass and patient counseling. We present what we believe to be the first case of SCT imaged in the first trimester using 3D ultrasound.

Transrectal scanning: an alternative when transvaginal scanning is not feasible

OBJECTIVE

In scanning the female pelvis the clear images of transvaginal sonography (TVS) result from placing the transducer close to the region of interest. The advantages of TVS over transabdominal sonography (TAS) and transperineal sonography are well documented. Transrectal scanning is proposed mostly for ultrasound guidance in draining a pelvic abscess. Our aim was to investigate the applicability of transrectal scanning (TRS) for cases in which TVS is impossible.

METHODS

Forty-two patients with an absolute or a relative contraindication to TVS were scanned transabdominally and transrectally. The TRS was performed using a transvaginal probe, which was lubricated and slowly advanced into the rectum. The technique used was similar to that of TVS. Images were compared for resolution and quality.

RESULTS

All scans were completed without significant patient discomfort or complaints. TRS was clearly superior to TAS in 31 cases. In nine cases TAS furnished some clinical information but TRS yielded better images. Only in one such case was TAS similar in quality to TRS. In four obese patients TAS did not reveal sufficient pelvic anatomy to generate a clinical diagnosis, whereas TRS revealed two sets of normal ovaries and two patients with ovarian cysts. In the two cases with vaginal agenesis TRS revealed the diagnosis of Rokitansky-Küster syndrome. In three of the four patients with ruptured membranes the cervix could be measured precisely.

CONCLUSION

Transrectal scanning should be used liberally after proper patient selection and counseling. The images obtained are superior to TAS and comparable to those obtained by TVS.

Saline infusion sonohysterography in nonpregnant women with previous cesarean delivery: the "niche" in the scar

OBJECTIVE

To apply an existing diagnostic imaging test (saline infusion sonohysterography) to characterize the "filling defect" of a previous cervical cesarean delivery scar in the nonpregnant uterus.

METHODS

Forty-four patients with histories of cesarean delivery who underwent saline infusion sonohysterography for a variety of gynecologic indications were included. During the procedure, the area below the bladder recess was examined using transvaginal sonography. A filling defect or "niche" was defined as a triangular anechoic structure at the presumed site of a previous cesarean delivery scar. The depth of the niche was measured. Uterine size, the presence of fibroids and polyps, and the number of previous cesarean deliveries were noted.

RESULTS

All patients had a niche indenting the anterior uterine-cervical wall. The mean +/- SD depth of the niche was 6.17 +/- 3.6 mm. There was no correlation between the number of cesarean deliveries and the depth of the niche. Thirty-six percent of our patients had fibroids, and 18% had endometrial polyps.

CONCLUSION

Saline infusion sonohysterography was able to detect filling defects in women who previously had cesarean deliveries. We hope that by focusing our attention on the transvaginal sonographic appearance of the detectable uterine scar (niche) with or without the use of saline infusion sonohysterography in the nonpregnant uterus, it will train our eyes to look for the scar in the pregnant uterus. In addition, our study patients had a high prevalence of abnormal uterine bleeding. The role of the cesarean delivery scar in women with unscheduled bleeding needs to be further evaluated.

Three-dimensional transvaginal neurosonography of the fetal brain: 'navigating' in the volume scan

OBJECTIVES

Fetal neuroscan by ultrasound has gained in importance over recent years. Two-dimensional (2D) transvaginal sonography was an important step in understanding the constantly changing and developing fetal brain. The objective of this article is to describe the use of three-dimensional ultrasound of the fetal brain enhanced by the transvaginal transfontanelle scanning technique.

METHODS

Thirty-four pregnant patients were referred to us because of a history of brain anomaly or suspected brain pathology. The fetuses were scanned transvaginally. Two-dimensional as well as three-dimensional (3D) images were generated. The volumes obtained by the 3D-ultrasound machine were displayed in the three conventional orthogonal planes (coronal, sagittal and axial).

RESULTS

Of the 34 fetuses 10 had normal brain anatomy and 24 had brain pathology. In all 34 cases the 2D images as well as the 3D volumes were of diagnostic quality and all three planes could be obtained. The axial sections could only be obtained by the 3D re-construction of the volume scans. The 2D images produced were acquired from a common point originating from the foot print of the transvaginal probe at the fetal anterior fontanelle or the sagittal suture, the sections 'radiate' from this point. Therefore, these sections are not parallel sections, but are oblique to each other. In contrast, the 3D volume could be examined using the classical parallel sections in all three orthogonal planes. The posterior fossa could be seen better if the footprint of the probe was placed over the posterior fontanelle or on the sagittal suture. The marker dot enabled a precise creation of anatomy and pathology. In the 'angio mode' it was possible to follow the anterior cerebral and pericallosal artery.

CONCLUSIONS

The 3D-ultrasound technology using the transvaginal approach is effective and practical to perform during fetal neuroscan. The ability to 'navigate' in the volume and the 'marker dot' enables exact location of normal structures and evaluation fetal brain pathology. The volume can be reviewed over and over again, can be mailed to an expert, could be shown to consultants (pediatric neurology and neurosurgeons) and used for teaching.