Early Abortions and Congenital Malformations: A Comparison Between Agricultural and Nonagricultural Areas in the State of São Paulo/Brazil.

INTRODUCTION: Areas with higher agricultural production have higher rates of abortion and malformation, probable related to pesticides. OBJECTIVE: To compare the rates of early abortion and fetal malformation in agricultural and nonagricultural areas. METHOD: A survey was carried out on fetal deaths in children weighing less than 500 g or gestational age less than 22 weeks and fetal malformations in live births. RESULTS: From 1996 to 2018, there was an increase in the rates of abortion and, albeit to a lesser extent, malformation. The areas of greater agricultural production have higher rates of fetal mortality and malformation than the others. CONCLUSIONS: The study suggests that areas with higher use of pesticides have higher rates of abortion and fetal malformations than the others, requiring further observational studies, reducing confounders inherent to the ecological study.

Does a three-degree hypoechogenicity grading improve ultrasound thyroid nodule risk stratification and affect the TI-RADS 4 category? A retrospective observational study.

Objective: The aim of this study was to determine whether classifying hypoechogenicity in three degrees (mild, moderate, and marked) could improve the distinction between benign and malignant nodules and whether such an approach could influence Category 4 of the Thyroid Imaging Reporting and Data System (TI-RADS). Materials and methods: In total, 2,574 nodules submitted to fine needle aspiration, classified by the Bethesda System, were retrospectively assessed. Further, a subanalysis considering solid nodules without any additional suspicious findings (n = 565) was performed with the purpose of evaluating mainly TI-RADS 4 nodules. Results: Mild hypoechogenicity was significantly less related to malignancy (odds ratio [OR]: 1.409; CI: 1.086-1.829; p = 0.01), compared to moderate (OR: 4.775; CI: 3.700-6.163; p < 0.001) and marked hypoechogenicity (OR: 8.540; CI: 6.355-11.445; p < 0.001). In addition, mild hypoechogenicity (20.7%) and iso-hyperechogenicity (20.5%) presented a similar rate in the malignant sample. Regarding the subanalysis, no significant association was found between mildly hypoechoic solid nodules and cancer. Conclusion: Stratifying hypoechogenicity into three degrees influences the confidence in the assessment of the rate of malignancy, indicating that mild hypoechogenicity has a unique low-risk biological behavior that resembles iso-hyperechogenicity, but with minor malignant potential when compared to moderate and marked hypoechogenicity, with special influence on the TI-RADS 4 category.

Characteristics of the learning curve in robotic thoracic surgery in an emerging country.

It is not established which factors impact the learning curve (LC) in robotic thoracic surgery (RTS), especially in emerging countries. The aim of this study is to analyze LC in RTS in Brazil and identify factors that can accelerate LC. We selected the first cases of two Brazilian surgeons who started their LC. We used CUSUM and the Lowess technique to measure LC for each surgeon and Poisson regression to assess factors associated with shorter console time (CT). 58 patients were operated by each surgeon and included in the analysis. Surgeries performed were different: Surgeon I (SI) performed 54 lobectomies (93.11%), whereas Surgeon II (SII) had a varied mix of cases. SI was proctored in his first 10 cases (17.24%), while SII in his first 41 cases (70.68%). The mean interval between surgeries was 8 days for SI and 16 days for SII. There were differences in the LC phases of the two surgeons, mainly regarding complications and conversions. There was shorter CT by 30% in the presence of a proctor, and by 20% with the Da Vinci Xi. Mix of cases did not seem to contribute to faster LC. Higher frequency between surgeries seems to be associated with a faster curve. Presence of proctor and use of bolder technologies reduced console time. We wonder if in phase 3 it is necessary to keep a proctor on complex cases to avoid serious complications. More studies are necessary to understand which factors impact the LC.

Unmeasured factors are associated with the use of completion lymph node dissection (CLND) in melanoma.

BACKGROUND: Completion lymph node dissection (CLND) was the standard treatment for patients with melanoma with positive sentinel lymph nodes (SLN) until 2017 when data from the DeCOG-SLT and MLST-2 randomized trials challenged the survival benefit of this procedure. We assessed the contribution of patient, tumor and facility factors on the use of CLND in patients with surgically resected Stage III melanoma. METHODS: Using the National Cancer Database, patients who underwent surgical excision and were found to have a positive SLN from 2012 to 2017 were included. A multivariable mixed-effects logistic regression model with a random intercept for the facility was used to determine the effect of patient, tumor, and facility variables on the risk of CLND. Reference effect measures (REMs) were used to compare the contribution of contextual effects (unknown facility variables) versus measured variables on the variation in CLND use. RESULTS: From 2012 to 2017, the overall use of CLND decreased from 59.9% to 26.5% (p < 0.0001). Overall, older patients and patients with government-based insurance were less likely to undergo CLND. Tumor factors associated with a decreased rate of CLND included primary tumor location on the lower limb, decreasing depth, and mitotic rate <1. However, the contribution of contextual effects to the variation in CLND use exceeded that of the measured facility, tumor, time, and patient variables. CONCLUSIONS: There was a decrease in CLND use during the study period. However, there is still high variability in CLND use, mainly driven by unmeasured contextual effects.

Does a three-degree hypoechogenicity grading improve ultrasound thyroid nodule risk stratification and affect the TI-RADS 4 category? A retrospective observational study

ABSTRACT Objective: The aim of this study was to determine whether classifying hypoechogenicity in three degrees (mild, moderate, and marked) could improve the distinction between benign and malignant nodules and whether such an approach could influence Category 4 of the Thyroid Imaging Reporting and Data System (TI-RADS). Materials and methods: In total, 2,574 nodules submitted to fine needle aspiration, classified by the Bethesda System, were retrospectively assessed. Further, a subanalysis considering solid nodules without any additional suspicious findings (n = 565) was performed with the purpose of evaluating mainly TI-RADS 4 nodules. Results: Mild hypoechogenicity was significantly less related to malignancy (odds ratio [OR]: 1.409; CI: 1.086-1.829; p = 0.01), compared to moderate (OR: 4.775; CI: 3.700-6.163; p < 0.001) and marked hypoechogenicity (OR: 8.540; CI: 6.355-11.445; p < 0.001). In addition, mild hypoechogenicity (20.7%) and iso-hyperechogenicity (20.5%) presented a similar rate in the malignant sample. Regarding the subanalysis, no significant association was found between mildly hypoechoic solid nodules and cancer. Conclusion: Stratifying hypoechogenicity into three degrees influences the confidence in the assessment of the rate of malignancy, indicating that mild hypoechogenicity has a unique low-risk biological behavior that resembles iso-hyperechogenicity, but with minor malignant potential when compared to moderate and marked hypoechogenicity, with special influence on the TI-RADS 4 category.

Refractory secondary hyperparathyroidism in waiting list for parathyroidectomy: who we should operate first in a quaternary hospital in Brazil regarding survival.

BACKGROUND: Few centers in Brazil perform parathyroidectomy (PTX) for recalcitrant secondary hyperparathyroidism (SHPT) generating a long queue. There is little data regarding prioritize criteria besides chronological order and survival. OBJECTIVES: To determine the difference of clinical and laboratory factors between PTX patients and those who remained in the line despite the need for surgery and their survival. METHODS: A retrospective cohort study was conducted in a quaternary hospital in Brazil, where 43 patients with PTX indication due to severe SHPT were followed from 2009 to 2016. While 31 patients underwent PTX, 12 remained in the queue. Data on clinical and laboratory factors were collected for comparison and Kaplan-Meier and Cox regression survival analysis were used. RESULTS: PTX group was younger (40.9 vs. 49.3 years, p = .03), had higher PTH levels (2578 vs. 1937 pg/ml, p = .01) and higher CaxP product (62 vs. 47.5, p = .02). There were no percentage differences between groups of fractures, calciphylaxis and other complications due to SHPT. Patients who were not operated had a worst overall survival (5 y 62.2% vs. 96.7%, p = .04) with a HR for death of 8.08 (p = .07, PTX as a TVC). Other variables associated with decreased survival included a history of previous myocardial infarction (HR: 10.4, p = .01) and age per additional year (HR: 1.09, p = .02). CONCLUSIONS: Patients with severe SHPT are at increased risk of death while waiting for PTX. Clinical events like fracture were not used to prioritize patients beyond consecutive order. Therefore, optimizing priority criteria for PTX may result in improved survival in this population.

Acurácia da tomografia computadorizada de múltiplos detectores no diagnóstico da doença arterial coronariana: revisão sistemática / Accuracy of multi-detector computed tomography for diagnosing coronary artery disease: systematic review

A doença arterial coronariana (DAC) é uma das condições mais prevalentes entre as doenças cardiovasculares. A angiografia coronariana invasiva (ACI) é o padrão de referência para o diagnóstico da DAC, sendo indicada quando há suspeita de estenose coronariana em pacientes com alta probabilidade de DAC. A angiocoronariografia com tomografia computadorizada de múltiplos detectores (TCMD) surgiu como nava técnica de diagnóstico, não invasiva, que permite a visão direta da artéria coronária. Sua indicação no diagnóstico de DAC, em pacientes sintomáticos com probabilidade pré-teste intermediária para essa condição, tem sido reportada. entretanto, os estudos apresentados até 2008 foram pequenos, de um único centro, envolvendo pacientes selecionados e, frequentemente, os segmentos com baixa nitidez de imagem eram excluídos da análise. O objetivo desta revisão sistemática foi avaliar a acurácia da TCMD no diagnóstico da DAC em pacientes que apresentavam probabilidade intermediária para essa condição. Dos 414 artigos encontrados, 13 estudos foram selecionados, os quais incluíam pacientes com probabilidade intermediária par DAC e que foram submetidos à angiocoronariografia invasica (ACI) e angiotomografia coronariana (ATC) de 64 detectores. Foram estudados 1992 pacientes em 12 dos 13 estudos selecionados, e somente oito estudos apresentaram dados disponíveis para a análise de 14725 segmentos coronarianas. Não houve diferença estatisticamente significativa...

Development of hepatic pseudotumors for image-guided interventional and surgical research in a large animal model.

PURPOSE: Real-time image guidance and navigation have become increasingly important in an era of minimally invasive interventional and surgical procedures in the liver. To develop, test, and implement tools for real-time image guidance, the authors sought to create an in vivo tumor mimic with realistic imaging and treatment capabilities. MATERIALS AND METHODS: Hepatic pseudotumors were created by injecting 1-2 mL of alginate (a hydrocolloid) directly into the liver parenchyma in eight live pigs and two dog cadavers. Tumors were imaged by B-mode ultrasound (US), US elasticity imaging, multi-detector row computed tomography (CT), CT fluoroscopy, and magnetic resonance (MR) imaging to assess imaging capabilities. Procedures performed with the alginate pseudotumors included radiofrequency (RF) ablation and robotic needle guidance. RESULTS: Twenty-four hepatic pseudotumors were created, ranging in size from 10 mm to 28 mm at an average depth of 6 mm. Average time of preparation and insertion was 3 minutes. All tumors were palpable under the surface of the liver and were easily visible on B-mode US, US elasticity imaging, CT, and MR imaging. Tumors were successfully "treated" with RF ablation, and gross examination of the liver showed good encompassment of the tumor by the zone of thermal coagulation. In addition, the pseudotumors allowed for easy introduction of various types of needles, including RF ablation probes and experimental steerable needles. CONCLUSIONS: Alginate pseudotumors can easily be imaged and allow for different procedures to be performed. This model can be used for various research purposes.

Intra-operative ultrasound elasticity imaging for monitoring of hepatic tumour thermal ablation.

BACKGROUND: Thermal ablation is an accepted therapy for selected hepatic malignancies. However, the reliability of thermal ablation is limited by the inability to accurately monitor and confirm completeness of tumour destruction in real time. We investigated the ability of ultrasound elasticity imaging (USEI) to monitor thermal ablation. OBJECTIVES: Capitalizing on the known increased stiffness that occurs with protein denaturation and dehydration during thermal therapy, we sought to investigate the feasibility and accuracy of USEI for monitoring of liver tumour ablation. METHODS: A model for hepatic tumours was developed and elasticity images of liver ablation were acquired in in vivo animal studies, comparing the elasticity images to gross specimens. A clinical pilot study was conducted using USEI in nine patients undergoing open radiofrequency ablation for hepatic malignancies. The size and shape of thermal lesions on USEI were compared to B-mode ultrasound and post-ablation computed tomography (CT). RESULTS: In both in vivo animal studies and in the clinical trial, the boundary of thermal lesions was significantly more conspicuous on USEI when compared with B-mode imaging. Animal studies demonstrated good correlation between the diameter of ablated lesions on USEI and the gross specimen (r = 0.81). Moreover, high-quality strain images were generated in real time during therapy. In patients undergoing tumour ablation, a good size correlation was observed between USEI and post-operative CT (r = 0.80). CONCLUSION: USEI can be a valuable tool for the accurate monitoring and real-time verification of successful thermal ablation of liver tumours.

A 2-microm continuous-wave laser system for safe and high-precision dissection during NOTES procedures.

INTRODUCTION: Lasers 2-microm in wavelength offer efficient tissue cutting with limited thermal damage in biological tissue. OBJECTIVE: To evaluate the dissection capabilities of a 2-microm continuous-wave laser for NOTES procedures. METHODS AND PROCEDURES: We conducted 18 acute animal experiments. Group 1 (three animals): transcolonic access to the peritoneal cavity (15-W transcolonic laser puncture, balloon dilation over the laser probe). Group 2 (six animals): transcolonic access with needle-knife puncture and balloon dilation. Group 3 (three animals): transgastric access to the peritoneal cavity (similar technique as group 1) followed by laser-assisted dissection of the kidney. In one animal of group 3, a therapeutic target (hematoma) was created by percutaneous puncture of the kidney. Group 4 (six animals): transgastric access (similar to the technique of group 2). RESULTS: Translumenal access to the peritoneal cavity was achieved in 2-3 min in group 1 (significantly shorter than with the needle-knife-assisted technique, 4-5 min, p=0.02) and in 7-10 min in group 3 (compared to 6-17 min in group 4, p=0.88). In group 3, laser dissection of the parietal peritoneum and of perinephric connective tissue allowed access to the retroperitoneum with complete removal of a blood collection in the animal with puncture trauma. Laser dissection demonstrated good maneuverability, clean and rapid cutting, and excellent hemostasis. Peritoneoscopy and necropsy showed no damage of targeted tissue and surrounding organs. CONCLUSIONS: The 2-microm continuous-wave laser system showed promising capabilities for highly precise and safe dissection during NOTES procedures.

Impact of obesity on perioperative outcomes and survival following pancreaticoduodenectomy for pancreatic cancer: a large single-institution study.

BACKGROUND: To examine the effect of body mass index (BMI) on clinicopathologic factors and long-term survival in patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma. METHODS: Data on BMI, weight loss, operative details, surgical pathology, and long-term survival were collected on 795 patients who underwent pancreaticoduodenectomy. Patients were categorized as obese (BMI > 30 kg/m(2)), overweight (BMI 25 to <30 kg/m(2)), or normal weight (BMI < 25 kg/m(2)) and compared using univariate and multivariate analyses. RESULTS: At the time of surgery, 14% of patients were obese, 33% overweight, and 53% normal weight. Overall, 32% of patients had preoperative weight loss of >10%. There were no differences in operative times among the groups; however, higher BMI was associated with increased risk of blood loss (P < 0.001) and pancreatic fistula (P = 0.01). On pathologic analysis, BMI was not associated with tumor stage or number of lymph nodes harvested (both P > 0.05). Higher BMI patients had a lower incidence of a positive retroperitoneal/uncinate margin versus normal weight patients (P = 0.03). Perioperative morbidity and mortality were similar among the groups. Obese and overweight patients had better 5-year survival (22% and 22%, respectively) versus normal weight patients (15%; P = 0.02). After adjusting for other prognostic factors, as well as preoperative weight loss, higher BMI remained independently associated with improved cancer-specific survival (overweight: hazard ratio, 0.68; obese: hazard ratio, 0.72; both P < 0.05). CONCLUSION: Obese patients had similar tumor-specific characteristics, as well as perioperative outcomes, compared with normal weight patients. However, obese patients undergoing pancreaticoduodenectomy for pancreatic cancer had an improved long-term survival independent of known clinicopathologic factors.

Infection during natural orifice transluminal endoscopic surgery: a randomized, controlled study in a live porcine model.

BACKGROUND: Currently reported natural orifice transluminal endoscopic surgery (NOTES) procedures in animals have been done in heterogeneous milieus ranging from nonsterile to sterile procedures, with mixed results, including no infection in those performed in nonsterile settings. OBJECTIVE: To establish the potential frequency of infection during NOTES, comparing sterile to nonsterile approaches. SETTING: Survival experiments on sixteen 50-kg pigs. DESIGN AND INTERVENTIONS: From pilot data (100% infection frequency after nonsterile procedures), sample size (8 animals in each group) was calculated by using a power of 95% and an alpha risk of 0.05. The animals were randomly assigned to two groups: In the transgastric peritoneoscopy study group, liver and ovarian biopsies were performed with sterile overtubes, endoscopes, and accessories and the use of preoperative intravenous antibiotics and antiseptic gastric lavage. In the nonsterile (control) group, the same procedures were performed with nonsterile endoscopes and accessories without the use of gastric lavage and preoperative antibiotics. Complete transmural closure of the transgastric access site was made in all animals. After a 1-week survival time, all animals were killed for necropsy, which included Gram staining and peritoneal cultures. MAIN OUTCOME MEASUREMENTS: Intraperitoneal infection on necropsy. RESULTS: All necropsies revealed intraperitoneal infection (abscesses, fibrinopurulent exudates, and adhesions) in the control group (frequency of infection 100%). Peritoneal bacterial culture grew various aerobic and anaerobic organisms. No gross or bacteriological evidence of infection was seen in the sterile group (frequency of infection 0%, P value = <.0002). LIMITATIONS: Animal experiments. CONCLUSION: Nonsterile conditions invariably lead to intraperitoneal infection. Aseptic techniques during NOTES can prevent intra-abdominal infection. Future studies will determine which infection prevention steps are mandatory and which can be omitted during NOTES procedures.

Omentoplasty for gastrotomy closure after natural orifice transluminal endoscopic surgery procedures (with video).

INTRODUCTION: The utility of the greater omentum has not been assessed in transluminal access closure after natural orifice transluminal endoscopic surgery (NOTES) procedures. OBJECTIVE: Our purpose was to evaluate the feasibility, efficacy, and safety of omentoplasty for gastrotomy closure. METHODS AND PROCEDURES: Survival experiments in 9 female 40-kg pigs were randomly assigned to 3 groups: group A, endoscopic full-thickness resection (EFTR) for transgastric access and peritoneoscopy without closure; group B, ETFR and peritoneoscopy with omentoplasty (flap of omentum is pulled into the stomach and attached to the gastric mucosa with clips but no clips are used for gastrotomy closure itself); group C, balloon dilation for opening and peritoneoscopy followed by omentoplasty for closure. The animals were observed for 2 weeks and then underwent endoscopy and necropsy with histologic evaluation. RESULTS: Transgastric opening and peritoneoscopy were achieved in all pigs. In groups B and C, a flap of omentum was easily placed to seal the gastrotomy and then attached to the gastric mucosa with 2 to 5 clips (median 4) in 7 to 20 minutes (median 15 minutes). In group A, peritonitis developed in all animals. In both groups B and C, all animals survived 15 days with no peritonitis and minimal adhesions outside the gastrotomy site. In addition, all achieved complete healing (transmural, n = 4; mucosal ulceration, n = 2) of the gastrotomy site. One animal in group B had an 18-mm abscess in the omental flap. LIMITATIONS: Animal model, small sample size, lack of appropriate controls for group C. CONCLUSIONS: Omentoplasty of the gastrotomy site is a technically feasible method to seal balloon-created transgastric access to the peritoneal cavity after NOTES procedures.

Hydrogen leak test is minimally invasive and highly specific for assessment of the integrity of the luminal closure after natural orifice transluminal endoscopic surgery procedures (with video).

BACKGROUND: Leak-resistant closure of transluminal access is a major challenge facing natural orifice transluminal endoscopic surgery (NOTES). OBJECTIVE: To evaluate a hydrogen (H(2))-based leak test for assessment of transluminal-access closure integrity after NOTES procedures. SETTING: Nine acute porcine experiments. DESIGN AND INTERVENTION: After gastric-wall puncture and balloon dilation, peritoneoscopy was performed, followed by transmural closure of the gastric opening. The animals were randomly assigned to complete or incomplete closure groups. The H(2) leak test was performed by using 1000 mL of 4% H(2) gas mixture and the Hydrogen Leak Detector H2000+. The animals were then euthanized for a methylene blue (MB) test of gastric closure integrity. MAIN OUTCOME MEASUREMENT: Intraperitoneal H(2) concentration after gastric insufflation with H(2). RESULTS: The H(2) leak test was quick and easy. Intraperitoneal H(2) concentrations in parts per million in both groups were similar at baseline (mean +/- SD, 0.18 +/- 0.29 parts per million [ppm] vs 0.22 +/- 0.35 ppm, P = .97) and after balloon dilation (414.8 +/- 198.5 ppm vs 601.3 +/- 116.1 ppm, P > .99). Postclosure intraperitoneal H(2) concentrations dropped to 0.01 +/- 0.77 ppm in the complete-closure group, similar (P = .81) to matched-pairs preopening levels and significantly lower than in the incomplete-closure group (162.0 +/- 83.0 ppm, P < .02). On necropsy, the MB test was negative in all 5 animals of the complete-closure group and positive in all 4 animals of the incomplete-closure group. A cutoff of 25 ppm in intraperitoneal H(2) concentration after closure gave 100% sensitivity, specificity, and positive and negative predictive values for MB leakage. LIMITATIONS: Nonsurvival animal experiments. CONCLUSIONS: The H(2) leak test is highly accurate for detection of leakage after NOTES procedures and could become a substitute for currently used MB leak tests.

Transgastric ventral hernia repair: a controlled study in a live porcine model (with videos).

BACKGROUND: Ventral hernia repair is currently performed via open surgery or laparoscopic approach. OBJECTIVE: To develop an alternative ventral hernia repair technique. SETTING: Acute and survival experiments on twelve 50-kg pigs. DESIGN AND INTERVENTIONS: An endoscope was introduced transgastrically into the peritoneal cavity. An abdominal wall hernia was created through a 5-mm skin incision followed by a 5-cm-long incision of the abdominal wall muscles and aponeurosis. A hernia repair technique was developed in 3 acute experiments. Then animals were randomized into 2 groups. In the experimental group (5 animals) Gore-Tex mesh was transgastrically attached to the abdominal wall, repairing the previously created abdominal wall hernia. In the control group (4 animals), the hernia was not repaired. In both groups, the endoscope was then withdrawn into the stomach, and the gastric wall incision was closed with T-bars. The animals survived for 2 weeks and were then euthanized. MAIN OUTCOME MEASUREMENT: The presence of ventral hernia on necropsy. RESULTS: In the control group, the ventral hernia was present on necropsy in all animals. In the experimental group, the ventral hernia was easily repaired, with no evidence of hernia on necropsy. In the first animal in the experimental group, necropsy revealed infected mesh. After this discovery, we used sterilized cover for mesh delivery and did not find any signs of infection in 4 subsequent study animals. LIMITATION: The study was performed in a porcine model. CONCLUSIONS: Transgastric ventral hernia repair is feasible, technically easy, and effective. It can become a less invasive alternative to the currently used laparoscopic and surgical ventral hernia repair.

Trends in nontherapeutic laparotomy rates in patients undergoing surgical therapy for hepatic colorectal metastases.

Surgery is the treatment of choice in selected patients with hepatic colorectal metastases. Despite improvements in preoperative imaging, patients can undergo unnecessary nontherapeutic laparotomy. The aim of this study was to examine trends in nontherapeutic laparotomy rates in patients undergoing planned surgical therapy for hepatic colorectal metastases. Data from 530 operations (461 patients) undergoing potentially curative surgical therapy for colorectal liver metastases between 1994 and 2005 were analyzed. The incidence of nontherapeutic laparotomy was determined and factors associated with nontherapeutic laparotomy were identified. Overall, 49 nontherapeutic laparotomies were performed (9.2%). Higher nontherapeutic laparotomy rates were seen in patients with multiple metastases and tumor size >5 cm (both P < 0.05). Preoperative positron emission tomography (PET) imaging was associated with lower risk of nontherapeutic laparotomy [5.6% versus 12.4%, P = 0.009, odds ratio (OR) = 0.42]. At laparotomy, extrahepatic findings were the reason for nontherapeutic laparotomy in 44.9% of cases. The nontherapeutic laparotomy rate significantly decreased over time (14.9% for 1994-1997 versus 9.6% for 1998-2001 versus 4.7% for 2002-2005; P = 0.003). While patients in each time period were similar with regard to tumor specific factors, utilization of PET imaging (P < 0.001) as well as resection plus ablation (P = 0.004) increased over time. We conclude that prevalence of nontherapeutic laparotomy for patients undergoing surgical exploration for hepatic colorectal metastases has decreased significantly in recent years to less than 5%. The reasons for this trend are probably multifactorial and may include improved preoperative assessment, such as PET imaging, as well as salvage surgical options.

Functional MR imaging as a new paradigm for image guidance.

Guidance and monitoring of locoregional minimally invasive treatment for primary or secondary liver tumor are critical to ensuring success and efficacy of therapy. In this article, we review advanced MR imaging techniques, including MR spectroscopy, diffusion and perfusion MR imaging, which can provide essential in vivo physiologic and metabolic information. These innovative imaging techniques can provide potential additional criteria to assess tumor response in addition to the accepted yet often limited Response Evaluation Criteria in Solid Tumors (RECIST) and the European Association for the Study of the Liver (EASL) criteria, which are based on decrease of tumor size and lesion enhancement, respectively. In this article, we also discuss the role of tumor size and enhancement in addition to apparent diffusion coefficient (ADC) findings after radiofrequency ablation (RFA), transarterial chemoembolization (TACE), and radioembolization.

Colorectal liver metastases: recurrence and survival following hepatic resection, radiofrequency ablation, and combined resection-radiofrequency ablation.

HYPOTHESIS: Although radiofrequency ablation (RFA) is increasingly an accepted option for patients with colorectal liver metastases, patients treated with resection vs RFA may have different tumor biology profiles, which might confound the relationship between choice of liver-directed therapy and outcome. DESIGN: Retrospective review of a prospectively collected database. SETTING: Major hepatobiliary center. PATIENTS: Between January 1, 1999, and August 30, 2006, 258 patients with colorectal liver metastases underwent hepatic resection with or without RFA. MAIN OUTCOME MEASURES: Evaluation of outcome following resection alone, combined resection-RFA, and RFA alone using 3 statistical methods (paired-match control, Cox proportional hazards multivariate model, and propensity index) to identify and adjust for potential confounding variables. RESULTS: The median number of hepatic lesions was 2, and the median size of the largest lesion was 3.0 cm. One hundred ninety-two patients (74.4%) underwent resection alone, 55 patients (21.3%) underwent resection-RFA, and 11 patients (4.3%) underwent RFA alone. Patients who underwent resection-RFA had significantly increased risk of extrahepatic failure at 1 year vs patients who underwent resection alone or RFA alone (P < .05). On matched control and multivariate analyses, patients who underwent RFA with or without resection had significantly worse disease-free and overall survival than patients who underwent resection alone. Propensity score methods revealed that the aggregate distribution of clinical risk factors for resection-RFA was markedly different from that for resection alone. This suggested a lack of comparability to allow for statistical comparisons in the assessment of causal inferences regarding the efficacy of RFA therapy. CONCLUSION: Although results of matched control and multivariate analyses suggested that RFA with or without resection was associated with worse outcome, propensity score methods revealed that the resection-RFA and resection-alone groups were different with regard to baseline tumor and treatment-related factors, making causal inferences about the efficacy of RFA unreliable.

Ablation monitoring with elastography: 2D in-vivo and 3D ex-vivo studies.

The clinical feasibility of 2D elastography methods is hindered by the requirement that the operator avoid out-of-plane motion of the ultrasound image during palpation, and also by the lack of volumetric elastography measurements. In this paper, we develop and evaluate a 3D elastography method operating on volumetric data acquired from a 3D probe. Our method is based on minimizing a cost function using dynamic programming (DP). The cost function incorporates similarity of echo amplitudes and displacement continuity. We present, to the best of our knowledge, the first in-vivo patient studies of monitoring liver ablation with freehand DP elastography. The thermal lesion was not discernable in the B-mode image but it was clearly visible in the strain image as well as in validation CT. We also present 3D strain images from thermal lesions in ex-vivo ablation. Good agreement was observed between strain images, CT and gross pathology.

Patterns of recurrence following liver resection for colorectal metastases: effect of primary rectal tumor site.

HYPOTHESIS: Patients with rectal adenocarcinoma are at increased risk of locoregional recurrence compared with patients with colon cancer. This may affect the pattern of recurrence and survival rates following hepatic resection of liver metastases from rectal adenocarcinoma. DESIGN: Retrospective review of a prospectively collected cancer center database. PATIENT AND METHODS: From April 1, 1984, to December 31, 2005, 582 patients with liver metastases from a primary colorectal adenocarcinoma underwent hepatic resection. Clinical and pathological factors were analyzed using Cox regression analyses and log-rank tests. RESULTS: Of 582 patients, 141 (24.2%) had liver metastases from a primary rectal tumor site. Treatment of the primary rectal tumor most frequently included chemoradiation therapy (59.6%) and low anterior resection (63.1%). Most rectal tumors were pathological stage T3/T4 (85.8%) and N1 (68.1%). Treatment directed at the hepatic metastases included resection only (81.5%), resection plus radiofrequency ablation (17.8%), or radiofrequency ablation only (0.7%). With a median follow-up time of 30.7 months, 80 of 141 patients (56.7%) developed recurrence; 23 patients (16.3%) developed recurrence in the pelvis. Of 23 patients with pelvic recurrence, 56.5% also developed recurrence in the liver. The 3- and 5-year survival rates for all patients were 62.4% and 36.4%, respectively. Of 80 patients who had a recurrence following hepatic metastectomy, 23 (28.8%) underwent another operation. Following repeat metastectomy, 3- and 5-year survival rates were 76.7% and 38.6%, respectively. CONCLUSIONS: Following resection of hepatic rectal metastases, pelvic recurrence is relatively common, and most patients with pelvic recurrence will also develop recurrence in the liver. Surgery for recurrent disease following hepatic resection of rectal metastases is warranted among well-selected patients.