Propensity Score-Matching Analysis Comparing Robotic Versus Laparoscopic Limited Liver Resections of the Posterosuperior Segments: An International Multicenter Study

OBJECTIVE

The purpose of this study was to compare the outcomes of robotic limited liver resections (RLLR) versus laparoscopic limited liver resections (LLLR) of the posterosuperior segments.

BACKGROUND

Both laparoscopic and robotic liver resections have been used for tumors in the posterosuperior liver segments. However, the comparative performance and safety of both approaches have not been well examined in the existing literature.

METHODS

This is a post hoc analysis of a multicenter database of 5446 patients who underwent RLLR or LLLR of the posterosuperior segments (I, IVa, VII, and VIII) at 60 international centers between 2008 and 2021. Data on baseline demographics, center experience and volume, tumor features, and perioperative characteristics were collected and analyzed. Propensity score-matching (PSM) analysis (in both 1:1 and 1:2 ratios) was performed to minimize selection bias.

RESULTS

A total of 3510 cases met the study criteria, of whom 3049 underwent LLLR (87%), and 461 underwent RLLR (13%). After PSM (1:1: and 1:2), RLLR was associated with a lower open conversion rate [10 of 449 (2.2%) vs 54 of 898 (6.0%); P =0.002], less blood loss [100 mL [IQR: 50-200) days vs 150 mL (IQR: 50-350); P <0.001] and a shorter operative time (188 min (IQR: 140-270) vs 222 min (IQR: 158-300); P <0.001]. These improved perioperative outcomes associated with RLLR were similarly seen in a subset analysis of patients with cirrhosis-lower open conversion rate [1 of 136 (0.7%) vs 17 of 272 (6.2%); P =0.009], less blood loss [100 mL (IQR: 48-200) vs 160 mL (IQR: 50-400); P <0.001], and shorter operative time [190 min (IQR: 141-258) vs 230 min (IQR: 160-312); P =0.003]. Postoperative outcomes in terms of readmission, morbidity and mortality were similar between RLLR and LLLR in both the overall PSM cohort and cirrhosis patient subset.

CONCLUSIONS

RLLR for the posterosuperior segments was associated with superior perioperative outcomes in terms of decreased operative time, blood loss, and open conversion rate when compared with LLLR.

Defining Global Benchmarks for Laparoscopic Liver Resections: An International Multicenter Study

OBJECTIVE

To establish global benchmark outcomes indicators after laparoscopic liver resections (L-LR).

BACKGROUND

There is limited published data to date on the best achievable outcomes after L-LR.

METHODS

This is a post hoc analysis of a multicenter database of 11,983 patients undergoing L-LR in 45 international centers in 4 continents between 2015 and 2020. Three specific procedures: left lateral sectionectomy (LLS), left hepatectomy (LH), and right hepatectomy (RH) were selected to represent the 3 difficulty levels of L-LR. Fifteen outcome indicators were selected to establish benchmark cutoffs.

RESULTS

There were 3519 L-LR (LLS, LH, RH) of which 1258 L-LR (40.6%) cases performed in 34 benchmark expert centers qualified as low-risk benchmark cases. These included 659 LLS (52.4%), 306 LH (24.3%), and 293 RH (23.3%). The benchmark outcomes established for operation time, open conversion rate, blood loss ≥500 mL, blood transfusion rate, postoperative morbidity, major morbidity, and 90-day mortality after LLS, LH, and RH were 209.5, 302, and 426 minutes; 2.1%, 13.4%, and 13.0%; 3.2%, 20%, and 47.1%; 0%, 7.1%, and 10.5%; 11.1%, 20%, and 50%; 0%, 7.1%, and 20%; and 0%, 0%, and 0%, respectively.

CONCLUSIONS

This study established the first global benchmark outcomes for L-LR in a large-scale international patient cohort. It provides an up-to-date reference regarding the "best achievable" results for L-LR for which centers adopting L-LR can use as a comparison to enable an objective assessment of performance gaps and learning curves.

Histopathological factors versus margin size in single colorectal liver metastases: Does a 1-cm margin size matter?

Background and objective:

The ideal margin width for surgical resection of colorectal liver metastases has been extensively studied, but not sufficiently in accordance with other pathological factors. The aim of this study was to assess for the first time the prognostic impact of margin widths according to different prognostic pathological factors in colorectal liver metastasis.

Methods:

We evaluated 101 patients with a single resected metastasis. Slides stained by HE were assessed for the presence of poorly differentiated clusters, peritumoral inflammatory infiltrate, tumor pseudocapsule, and tumor borders pattern. Overall survival, disease-free survival, and hepatic recurrence were evaluated. The pathologic factors prognostic impact was evaluated according to a (< or ⩾) 10-mm margin size.

Results:

Factors independently associated with a shorter overall survival were absence of tumor pseudocapsule ( p < 0.001) and infiltrative tumor border pattern ( p = 0.019). The absence of tumor pseudocapsule was the only factor independently associated with shorter disease-free survival ( p < 0.001). Hepatic recurrence was associated with infiltrative tumor border and absence of pseudocapsule. Margin width ⩾10 mm did not impact overall survival independently of the studied histological prognostic factors.

Conclusions:

In colorectal liver metastasis resection, the absence of tumor pseudocapsule was significantly associated with shorter overall survival and disease-free survival and hepatic recurrence. However, margins larger than 10 mm did not offer survival benefit when other pathologic negative prognostic factors were concomitantly analyzed, reinforcing the idea that biology, rather than margin size, is crucial for prognosis.

Size-dependent sex allocation in Solanum lycocarpum St. Hil. (Solanaceae)

Resource allocation to reproduction can change depending on size, as predicted by the size-dependent sex allocation. This theory is based on the fact that small individuals will invest in the allocation of sex with lower cost of production, usually male gender. In plants, there are some andromonoecy species, presence of hermaphrodite and male flowers in the same individual. Andromonoecy provides a strategy to optimally allocate resources to male and female function, evolving a reproductive energy-saving strategy. Thus, our objective was to investigate the size-dependent sex allocation in Solanum lycocarpum St. Hil. We tested the hypothesis that plants with larger size will invest in the production of hermaphrodite flowers, because higher individuals have greater availability of resources to invest in more complex structures involving greater energy expenditure. The studied species was S. lycocarpum, an andromonoecious species. From June 2016 to March 2017 the data were collected in 38 individuals, divided in two groups: the larger plant group (n=18; height=3-5 m) and the smaller plant group (n=20; height=1-2 m).Our data show that there was effect of plant size on the flower production and the sexual gender allocation. The larger plants showed more flowers and higher production of hermaphrodite flowers. Furthermore, in the flower scale, we observed allometric relationship among the flower's traits with proportional investments in biomass, anther size and gynoecium size. Our results are in agreement with size-dependent sex allocation theory and andromonoecy hypothesis related to mechanisms for optimal resource allocation to male and female function.

Combined liver and multivisceral resections: A comparative analysis of short and long-term outcomes

BACKGROUND

En bloc liver and adjacent organs resections are technically demanding procedures. Few case series and nonmatched comparative studies reported the outcomes of multivisceral liver resections (MLRs).

OBJECTIVES

To compare the short and long-term outcomes of patients submitted MLRs with those submitted to isolated hepatectomies.

METHODS

From a prospective database, a case-matched 1:2 study was performed comparing MLRs and isolated hepatectomy. Additionally, a risk analysis was performed to evaluate the association between MLRs and perioperative morbidity, mortality, and long-term survival.

RESULTS

Fifty-three MLRs were compared with 106 matched controls. Patients undergoing MLRs had longer operative time (430 [320-525] vs 360 [270-440] minutes, P = .005); higher estimated blood loss (600 [400-800] vs 400 [100-600] mL; P = .011); longer hospital stay (8 [6-14] vs 7 [5-9] days; P = .003); and higher postoperative mortality (9.4% vs 1.9%, P = .042). Number of resected organs was not an independent prognostic factor for perioperative major complications (odds ratio [OR], 1 organ = 1.8 [0.54-6.05]; OR ≥ 2, organs = 4.0 [0.35-13.84]) or perioperative mortality (OR, 1, organ = 5.2 [0.91-29.51]; OR ≥ 2, organs = 6.5 [0.52-79.60]). No differences in overall (P = .771) and disease-free survival (P = .28) were observed.

CONCLUSION

MLRs are feasible with acceptable morbidity but relatively high perioperative mortality. MLRs did not negatively affect long-term outcomes.

Laparoscopic Liver Resection: A South American Experience with 2887 Cases

BACKGROUND

Laparoscopic liver resections (LLR) have been increasingly performed in recent years. Most of the available evidence, however, comes from specialized centers in Asia, Europe and USA. Data from South America are limited and based on single-center experiences. To date, no multicenter studies evaluated the results of LLR in South America. The aim of this study was to evaluate the experience and results with LLR in South American centers.

METHODS

From February to November 2019, a survey about LLR was conducted in 61 hepatobiliary centers in South America, composed by 20 questions concerning demographic characteristics, surgical data, and perioperative results.

RESULTS

Fifty-one (83.6%) centers from seven different countries answered the survey. A total of 2887 LLR were performed, as follows: Argentina (928), Brazil (1326), Chile (322), Colombia (210), Paraguay (9), Peru (75), and Uruguay (8). The first program began in 1997; however, the majority (60.7%) started after 2010. The percentage of LLR over open resections was 28.4% (4.4-84%). Of the total, 76.5% were minor hepatectomies and 23.5% major, including 266 right hepatectomies and 343 left hepatectomies. The conversion rate was 9.7%, overall morbidity 13%, and mortality 0.7%.

CONCLUSIONS

This is the largest study assessing the dissemination and results of LLR in South America. It showed an increasing number of centers performing LLR with the promising perioperative results, aligned with other worldwide excellence centers.

Preoperative strategies to improve resectability for hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

Preoperative strategies to increase the future liver remnant are useful methods to improve resectability rates for patients with hepatocellular carcinoma (HCC). The aim of this study was to perform a systematic review and meta-analysis of the main strategies used for this purpose.

METHODS

A systematic review was performed in PubMed, EMBASE, Cochrane and Scielo/LILACS. The procedures included for analysis were portal vein embolization or ligation (PVE/PVL), sequential transarterial embolization and PVE (TACE + PVE), radioembolization (RE) and associated liver partition and portal vein ligation for staged hepatectomy (ALPPS). Perioperative morbidity and mortality, post-hepatectomy liver failure (PHLF), and survival rates were evaluated.

RESULTS

A total of 46 studies were included in the systematic review (1284 patients). Resection rate was higher in TACE + PVE (90%; N = 315) when compared to PVE/PVL (75%; N = 254; P = <0.001) and similar to ALPPS (84%; N = 43; P = 0.374) and RE (100%; N = 28; P = 0.14). ALPPS was associated with higher PHLF and perioperative mortality rates when compared to PVE/PVL and TACE + PVE. ALPPS and RE showed higher risk of major complications than PVE/PVL and TACE + PVE.

CONCLUSION

Preoperative strategies to increase liver volume are effective in achieving resectability of HCC. TACE + PVE is as safe as PVL/PVE providing higher OS. ALPPS is associated with a higher risk of PHLF, major complications, and mortality. RE despite the small experience seems to present similar resection rate and OS as TACE + PVE with higher rate of major complications.

Pathological factors and prognosis of resected liver metastases of colorectal carcinoma: implications and proposal for a pathological reporting protocol

Colorectal cancer is a leading cause of death worldwide. The liver is the most common site of distant metastases, and surgery is the only potentially curative treatment, although the recurrence rate following surgery is high. In order to define prognosis after surgery, many histopathological features have been identified in the primary tumour. In turn, pathologists routinely report specific findings to guide oncologists on the decision to recommend adjuvant therapy. In general, the pathological report of resected colorectal liver metastases is limited to confirmation of the malignancy and details regarding the margin status. Most pathological reports of a liver resection for colorectal liver metastasis lack information on other important features that have been reported to be independent prognostic factors. We herein review the evidence to support a more detailed pathological report of the resected liver specimen, with attention to: the number and size of liver metastases; margin size; the presence of lymphatic, vascular, perineural and biliary invasion; mucinous pattern; tumour growth pattern; the presence of a tumour pseudocapsule; and the pathological response to neoadjuvant chemotherapy. In addition, we propose a new protocol for the evaluation of colorectal liver metastasis resection specimens.

Hand-assisted Approach as a Model to Teach Complex Laparoscopic Hepatectomies: Preliminary Results

BACKGROUND

Currently, there are limited and scarce models to teach complex liver resections by laparoscopy. The aim of this study is to present a hand-assisted technique to teach complex laparoscopic hepatectomies for fellows in liver surgery.

MATERIALS AND METHODS

Laparoscopic hand-assisted approach for resections of liver lesions located in posterosuperior segments (7, 6/7, 7/8, 8) was performed by the trainees with guidance and intermittent intervention of a senior surgeon. Data as: (1) percentage of time that the senior surgeon takes the surgery as main surgeon, (2) need for the senior surgeon to finish the procedure, (3) necessity of conversion, (4) bleeding with hemodynamic instability, (5) need for transfusion, (6) oncological surgical margins, were evaluated.

RESULTS

In total, 12 cases of complex laparoscopic liver resections were performed by the trainee. All cases included deep lesions situated on liver segments 7 or 8. The senior surgeon intervention occurred in a mean of 20% of the total surgical time (range, 0% to 50%). A senior intervention >20% was necessary in 2 cases. There was no need for conversion or reoperation. Neither major bleeding nor complications resulted from the teaching program. All surgical margins were clear.

CONCLUSIONS

This preliminary report shows that hand-assistance is a safe way to teach complex liver resections without compromising patient safety or oncological results. More cases are still necessary to draw definitive conclusions about this teaching method.

Favorable Long-term Outcome in Patients Submitted to Liver Transplantation After Downstaging of Hepatocellular Carcinoma According to a Brazilian Selection Protocol

BACKGROUND

In October 2008, the Brazilian Ministry of Health authorized listing of downstaged hepatocellular carcinoma (HCC) for liver transplantation, according to a standardized protocol. The aim of this study was to compare the outcome of patients submitted to liver transplantation after downstaging of HCC with the results other standard indications in Brazil.

METHODS

We conducted a retrospective analysis of 2,667 adult 1st elective deceased-donor liver transplantations registered at the database of the Transplant Notification Center of the São Paulo State Health Secretariat. These cases are classified into 3 groups: "cirrhosis," including 1,709 patients transplanted because of end-stage liver disease; "Milan-HCC," including 873 HCC patients initially meeting the Milan criteria; and "downstaging" group, including 85 HCC patients submitted to tumor downstaging to the Milan criteria before liver transplantation.

RESULTS

One-, 3-, 5-, and 6-year patients survivals were, respectively, 82.7%, 72.0%, 66.1%, and 66.1%, in the "downstaging" group and 76.7%, 68.4%, 63.9%, and 63.5% in the "Milan-HCC" group (P = .483). At the same time intervals, patient survivals were 67.8%, 62.9%, 60.9%, and 60.2% in the "cirrhosis" group. These probabilities were significantly lower than those of both "downstaging" (P = .047) and "Milan-HCC" (P = .001) groups.

CONCLUSIONS

Patients submitted to liver transplantation after downstaging of HCC, according to a Brazilian selection protocol, present long-term outcomes similar to HCC patients initially within the Milan criteria and better survival than recipients with end-stage liver disease.

Detection of aneuploidies in spontaneous abortions by quantitative fluorescent PCR with short tandem repeat markers: a retrospective study

Approximately 10-15% of all pregnancies end in spontaneous abortions. Many factors can lead to embryonic loss; however, it has been well established that over 50% of all miscarriages result from chromosomal abnormalities, primarily aneuploidies (>96%). Identifying the cause of miscarriage can significantly reduce the psychological stress in women, and enable better genetic counseling for a future pregnancy. Quantitative fluorescent polymerase chain reaction (QF-PCR) has been previously used in the study of chromosomal abnormalities. In this retrospective study, the frequency of aneuploidy in samples of 130 miscarriages undergone by patients (age average: 34.1 ± 4.6 years) at our institution was determined by QF-PCR using short tandem repeat markers. The gender of the miscarriage cases was determined by amplifying the amelogenin locus (70 males and 60 females). Seventy-one of these cases (54.6%) presented aneuploidies such as trisomy, monosomy, triploidy, and double trisomy. Trisomy 22 was the most common aneuploidy (present in 14 cases), followed by trisomy 15, trisomy 16, and monosomy X. We also observed monosomy at chromosomes X and 21 and a case with multiple aneuploidies at chromosomes 16 and 22. The most common aneuploidies associated with miscarriages were detected by QF-PCR; therefore, we concluded that QF-PCR is a rapid and reliable method for the detection of aneuploidy, and can be used as an accessory to the widely used karyotype analysis.

Extended right hepatectomy with caudate lobe resection using the hilar "en bloc" resection technique with a modified hanging maneuver

The hanging liver maneuver is a useful technique to guide the transection of liver parenchyma by lifting a tape passed between the anterior surface of the inferior vena cava and the liver. Modified hanging liver maneuvers have been described in different types of liver resection. Surgical resection of hilar cholangiocarcinoma can involve the portal vein and the caudate lobe for margin clearance. However, hilar dissection and resection of the caudate lobe can be a challenging during the hanging maneuver once the tape is positioned. Herein, we describe a modified hanging liver maneuver for a hilar "en bloc" extended right hepatectomy with portal vein resection for the treatment of hilar cholangiocarcinoma including the caudate lobe. J. Surg. Oncol. 2016;113:427-431. © 2016 Wiley Periodicals, Inc.

Liver resection for the treatment of post-cholecystectomy biliary stricture with vascular injury

AIM: To report experience with liver resection in a select group of patients with postoperative biliary stricture associated with vascular injury.

METHODS: From a prospective database of patients treated for benign biliary strictures at our hospital, cases that underwent liver resections were reviewed. All cases were referred after one or more attempts to repair bile duct injuries following cholecystectomy (open or laparoscopic). Liver resection was indicated in patients with Strasberg E3/E4 (hilar stricture) bile duct lesions associated with vascular damage (arterial and/or portal), ipsilateral liver atrophy/abscess, recurrent attacks of cholangitis, and failure of previous hepaticojejunostomy.

RESULTS: Of 148 patients treated for benign biliary strictures, nine (6.1%) underwent liver resection; eight women and one man with a mean age of 38.6 years. Six patients had previously been submitted to open cholecystectomy and three to laparoscopic surgery. The mean number of surgical procedures before definitive treatment was 2.4. All patients had Strasberg E3/E4 injuries, and vascular injury was present in all cases. Eight patients underwent right hepatectomy and one underwent left lateral sectionectomy without mortality. Mean time of follow up was 69.1 mo and after long-term follow up, eight patients are asymptomatic.

CONCLUSION: Liver resection is a good therapeutic option for patients with complex postoperative biliary stricture and vascular injury presenting with liver atrophy/abscess in which previous hepaticojejunostomy has failed.

Water level-dependent morphological plasticity in Sagittaria montevidensis Cham. and Schl. (Alismataceae)

Aquatic plants are able to alter their morphology in response to environmental condition variation, such as water level fluctuations. The aim of this study was to evaluate the effect of water level on Sagittaria montevidensis morphology through measures of vegetative structures formed in drought and flood periods. We hypothesised that the plant height and the biomass of S. montevidensis leaves will increase during flood periods, while the biomass and diameter of petioles, and the basal plant area will increase during dry periods. We sampled a total amount of 270 individuals in nine sediment banks per visit, totalling 1080 plants. In order to compare plant morphology between dry and flood periods, we measured the water level in each bank and took the following variables for each plant: diameter, height and diameter of the biggest petiole. In order to compare biomass allocation between dry and flood periods, we sampled a total amount of 90 individuals in nine sediment banks per visit, totalling 360 plants. Plants were dried and weighed in the laboratory. All measured morphologic traits, as well as the biomass of leaf blades and petioles, were higher during flood periods, indicating that water level highly influences the morphology of S. montevidensis individuals. Our results suggest that these morphological responses allow survival and maintenance of S. montevidensis populations under environmental stress. These results can be linked to the invasive potential of S. montevidensis and sheds light on basic management practices that may be applied in the future.

Soil factors effects on life history attributes of Leiothrix spiralis and Leiothrix vivipara (Eriocaulaceae) on rupestrian grasslands in Southeastern Brazil

In this study, we hypothesized that the life history traits of Leiothrix spiralis and L. vivipara would be linked to soil factors of the rupestrian grasslands and that rosette size would be influenced by soil moisture. Soil analyses were performed from five populations of L. spiralis and four populations of L. vivipara. In each area, three replicates were employed in 19 areas of occurrence of Leiothrix species, and we quantified the life history attributes. The microhabitats of these species show low favorability regarding to soil factors. During the dry season, their rosettes decreased in diameter due the loss of its most outlying leaves. The absence of seedlings indicated the low fecundity of both species. However, both species showed rapid population growth by pseudovivipary. Both L. spiralis and L. vivipara exhibit a kind of parental care that was quantified by the presence of connections between parental-rosettes and ramets. The findings of the present study show that the life history traits are linked to soil factors.

Body size and clonality consequences for sexual reproduction in a perennial herb of Brazilian rupestrian grasslands

Body size is one of the most important factors regarding herbaceous perennial plants life-histories, and several fitness components of these organisms are related to size. Clonal plants show distinct kinds of reproduction and can develop offspring by sexual or asexual ways. We aimed to understand how body size affects Comanthera nivea (Eriocaulaceae) sexual reproduction and to verify how clonal growth is related to flower head production in this species. We sampled 600 rosettes in rupestrian grasslands and performed linear regression analysis between body size and number of produced flower heads. We also compared the flower head production between isolated rosettes and rosettes within clones. Our results showed that body size was significantly related, but explained only a small part of flower head production. The flower head production was higher in rosettes within clones than in isolated ones. The clones presented a rosette or a small group of rosettes that concentrated the sexual reproduction. Clonality was positively associated with sexual reproduction. Clonality can represent an important way of allowing the persistence of plants by sexual reproduction in markedly seasonal stressful environments. The cases of clonality enhancing the sexual reproduction must be considered and put in focus on reproductive biology research.

Dimensão da margem cirúrgica nas ressecções de metástase hepática de câncer colorretal: impacto na recidiva e sobrevida

RACIONAL: Aproximadamente 50% dos pacientes com tumor colorretal apresentam metástase hepática sendo a hepatectomia o procedimento terapêutico de escolha. Discutem-se diversos fatores prognósticos; entre eles, a margem cirúrgica é fator sempre recorrente, pois não existe consenso da distância mínima necessária entre o nódulo metastático e a linha de secção hepática. OBJETIVOS: Avaliar as margens cirúrgicas nas ressecções de metástases hepáticas de câncer colorretal e sua correlação com recidiva local e sobrevida. MÉTODOS: Estudo retrospectivo, baseado na revisão dos prontuários de 91 pacientes submetidos à ressecção de metástases hepáticas de neoplasia colorretal. Foi realizada revisão histopatológica de todos os casos com aferição da menor margem cirúrgica e observar o resultado tardio em relação à recidiva e sobrevida. RESULTADOS: Não houve diferença estatística nas taxas de recidiva e no tempo de sobrevivência global entre os pacientes com margens livres ou acometidas (R0vsR1), assim como não houve diferença entre as margens subcentimétricas e as maiores de 1 cm. A sobrevida livre de doença dos pacientes com margens microscopicamente acometidas foi significativamente menor do que dos com margens livres. A análise uni e multivariada não identificou a margem cirúrgica (R1, exígua ou menor que 1 cm) como fator de risco para recidiva. CONCLUSÕES: As ressecções de metástases hepáticas com margens livres de doença, independentemente das dimensões da margem, não influenciou na recidiva tumoral (intra ou extra-hepática) ou na sobrevida dos pacientes.

Tumor growth pattern as predictor of colorectal liver metastasis recurrence

BACKGROUND

Surgical resection is the gold standard therapy for the treatment of colorectal liver metastases (CRM). The aim of this study was to investigate the impact of tumor growth patterns on disease recurrence.

METHODS

We enrolled 91 patients who underwent CRM resection. Pathological specimens were prospectively evaluated, with particular attention given to tumor growth patterns (infiltrative vs pushing).

RESULTS

Tumor recurrence was observed in 65 patients (71.4%). According to multivariate analysis, 3 or more lesions (P = .05) and the infiltrative tumor margin type (P = .05) were unique independent risk factors for recurrence. Patients with infiltrative margins had a 5-year disease-free survival rate significantly inferior to patients with pushing margins (20.2% vs 40.5%, P = .05).

CONCLUSIONS

CRM patients with pushing margins presented superior disease-free survival rates compared with patients with infiltrative margins. Thus, the adoption of the margin pattern can represent a tool for improved selection of patients for adjuvant treatment.

The use of Salvinia auriculata as a bioindicator in aquatic ecosystems: biomass and structure dependent on the cadmium concentration

This study shows, in a multiple-level approach, the responses of Salvinia auriculata to Cd pollution in aquatic ecosystems. S. auriculata ramets were cultivated in nutrient solution and subjected to five treatments with Cd for ten days. At the end of the experiment, the number of new ramets and the dry biomass were determined. For ultrastructural observations, the leaves of S. auriculata were analyzed using a scanning electron microscope and transmission electron microscope. At the end of the experiment, the plants exposed to Cd showed damage in the leaves including necrosis and chlorosis, stomate deformations and damaged trichomes. We observed a decrease in the number of new ramets and dry biomass of S. auriculata following the increase in Cd concentration in the solution. At the ultrastructural level, leaves exposed to Cd presented chloroplast deformations and deterioration in the cell wall. All the symptoms of toxicity were directly proportionate to the concentration of Cd in the solution. The results suggests that S. auriculata shows good potential for use as a bioindicator and it can be used in the biomonitoring of aquatic ecosystems contaminated by Cd.

Apolipoprotein A5-1131T>C polymorphism, but not APOE genotypes, increases susceptibility for dyslipidemia in children and adolescents

Apolipoprotein A5 (APOA5) and apolipoprotein E (APOE) play important roles in the metabolism of cholesterol and triglycerides. The aim of this study was to determine the allelic and genotypic distributions of the APOA5-1131T>C (rs 662799) and the APOE HhaI polymorphisms and to identify the association of both individual and combined APOA5-APOE genetic variants and the risk for dyslipidemia in children and adolescents. We genotyped 53 dyslipidemic and 77 normolipidemic individuals. The total cholesterol, triglycerides and HDL cholesterol were determined enzymatically. For APOA5 polymorphism, the presence of the allele C confers an individual risk for dyslipidemia (OR = 2.38, 95% CI = 1.15-4.89; P = 0.018). No significant differences were observed for lipid parameters among the APOA5 groups, except for a higher value of HDLc (P = 0.024) in C-carriers. The allelic and genotypic frequencies of APOE polymorphism were similar between groups and did not increase the susceptibility for dyslipidemia. None of the combined APOA5-APOE polymorphisms increased risk for dyslipidemia. We demonstrated an association between APOA5-1131T>C polymorphism and dyslipidemia in children and adolescents. This finding may be useful to guide new studies with genetic markers down a path toward a better characterization of the genetic risk factors for dyslipidemia and atherosclerotic diseases.

Lymphadenectomy in colorectal cancer liver metastases resection: incidence of hilar lymph nodes micrometastasis

BACKGROUND

Liver resection is considered the best treatment for metastatic colorectal cancer. Several prognostic factors have been investigated, and many studies have shown that hepatic hilum lymph nodes involvement has a negative impact on prognosis. The present study evaluated the frequency of microscopic involvement of hilar lymph nodes, through systematic lymphadenectomy and analysis of micrometastases in patients undergoing hepatectomy due to colorectal metastasis.

METHODS

A total of 28 patients underwent hepatic resection with hilar lymphadenectomy. Lymph nodes considered negative by conventional hematoxylin and eosin (H&E) staining were analyzed by serial sectioning with 100-microm intervals and immunohistochemistry (IHC) with anti-human pancytokeratin antibody AE1/AE3.

RESULTS

In average, 6.18 lymph nodes were dissected per patient. No morbidity or mortality was associated to lymphadenectomy. In two patients, conventional H&E analysis showed presence of microscopic lymph node metastasis. IHC analysis allowed the identification of three other patients with lymph node micrometastases. The overall frequency of microscopic metastases, including micrometastasis, was 18%.

CONCLUSIONS

Systematic lymphadenectomy allowed the detection of microscopic lymph node metastases, resulting in more accurate staging of extrahepatic disease. The inclusion of IHC increased the detection of lymph node micrometastasis.

Influence of ischemic preconditioning in myocardial protection in patients undergoing myocardial revascularization with intermittent crossclamping of the aorta. Analysis of ions and blood gases

OBJECTIVE

To test the hypothesis that short periods of ischemia may increase the myocardial protection obtained with intermittent crossclamping of the aorta.

METHODS

In the control group (18 patients), surgery was performed with systemic hypothermia at 32 degrees C and intermittent crossclamping of the aorta. Extracorporeal circulation was used. In the preconditioning group (17 patients), 2 crossclampings of the aorta lasting 3min each were added prior to the intermittent crossclamping of the conventional technique with an interval of 2min of reperfusion between them. Blood samples for analyses of pH, pCO2, pO2, sodium, potassium, calcium, and magnesium were obtained from the coronary sinus at the beginning of extracorporeal circulation (time 1), at the end of the first anastomosis (time 2), and at the end of extracorporeal circulation (time 3).

RESULTS

No difference was observed in the results of the 2 groups, except for a variation in the ionic values in the different times of blood withdrawal; sodium values, however, remained stable. All patients had a good clinical outcome.

CONCLUSION

The results of intermittent crossclamping of the aorta with moderate hypothermia were not altered by the use of ischemic preconditioning.

The use of bone bridges in transtibial amputations

We sought to describe the bone bridge technique in adults, and present a variation for use in children, as well as to present its applicability as an option in elective transtibial amputations. This paper presents a prospective study of 15 transtibial amputations performed between 1992 and 1995 in which the bone bridge technique was employed. The patients' ages ranged from 8 to 48 years, with an average of 22.5 years. This technique consisted of the preparation of a cylinder of periosteum extracted from the tibia and with cortical bone fragments attached to it to promote a tibiofibular synostosis on the distal extremity of the amputation stump. We noted that the cortical bone fragments were dispensable when the technique was employed in children, due to the increased osteogenic capacity of the periosteum. This led to a variation of the original technique, a bone bridge without the use of the cortical bone fragments.

RESULTS

The average time spent with this procedure, without any significant variation between adults and children, was 171 minutes. The adaptation to the definitive prosthesis was accomplished between 20 and 576 days, with an average of 180 days. Revision of the procedure was necessary in 3 amputations.

CONCLUSIONS

This technique may be employed in transtibial amputations in which the final length of the stump lies next to the musculotendinous transition of the gastrocnemius muscle, as well as in the revision of amputation stumps in children, where the procedure has been shown to be effective in the prevention of lesions due to excessive bone growth.