Psoas muscle index is not representative of skeletal muscle index for evaluating cancer sarcopenia.

BACKGROUND: A common method for diagnosing sarcopenia involves estimating the muscle mass by computed tomography (CT) via measurements of the cross-sectional muscle area (CSMA) of all muscles at the third lumbar vertebra (L3) level. Recently, single-muscle measurements of the psoas major muscle at L3 have emerged as a surrogate for sarcopenia detection, but its reliability and accuracy remain to be demonstrated. METHODS: This prospective cross-sectional study involved 29 healthcare establishments and recruited patients with metastatic cancers. The correlation between skeletal muscle index (SMI = CSMA of all muscles at L3/height2 , cm2 /m2 ) and psoas muscle index (PMI = CSMA of psoas at L3/height2 , cm2 /m2 ) was determined (Pearson's r). ROC curves were prepared based on SMI data from a development population (n = 488) to estimate suitable PMI thresholds. International low SMI cut-offs according to gender were studied for males (<55cm2 /m2 ) and for females (<39 cm2 /m2 ). Youden's index (J) and Cohen's kappa (κ) were calculated to estimate the test's accuracy and reliability. PMI cut-offs were validated in a validation population (n = 243) by estimating the percentage concordance of sarcopenia diagnoses with the SMI thresholds. RESULTS: Seven hundred and sixty-six patients were analysed (mean age 65.0 ± 11.8 years, 50.1% female). Low SMI prevalence was 69.1%. Correlation between the SMI and PMI for the entire population was 0.69 (n = 731, P < 0.01). PMI cut-offs for sarcopenia were estimated in the development population at <6.6cm2 /m2 in males and at <4.8 cm2 /m2 for females. The J and κ coefficients for PMI diagnostic tests were weak. The PMI cut-offs were tested in the validation population where 33.3% of the PMI measurements were dichotomously discordant. CONCLUSIONS: A diagnostic test employing single-muscle measurements of the psoas major muscle as a surrogate for sarcopenia detection was evaluated but found to be unreliable. The CSMA of all muscles must be considered for evaluating cancer sarcopenia at L3.

Robotic Resection of a Central Liver Solitary Fibrous Tumor (with Video).

BACKGROUND: Solitary fibrous tumor is a mesenchymal tumor rare in liver parenchyma 1 but must be considered as a differential diagnosis of a single large hepatic mass. Surgical resection is the treatment because of its potential malignancy, and previous interventions reported were open hepatectomy 2. Robotic assets could improve accessibility for difficult liver resection 3. We present the video of a robotic left hepatectomy extended to caudate lobe and median hepatic vein for central liver tumor. METHODS: A central liver tumor was incidentally detected during abdominal ultrasonography in a 30-year-old man with no medical history. Laboratory tests were normal. CT scan and MRI revealed a solid mass measuring 9 cm involving segments I-IV-VIII and median/left hepatic veins. Percutaneous biopsy confirmed diagnosis of benign liver solitary fibrous tumor. Surgical resection by left hepatectomy extended to segment 1 and median hepatic vein was planned. RESULTS: Da Vinci X system was docked from patient's head. Four robotic ports were placed in right hypochondrium. Two laparoscopic ports were placed for the second surgeon. Extended left hepatectomy was performed with hilar approach. Parenchymal transection was led on the right side of median hepatic vein using laparoscopic ultrasonic dissector and robotic irrigated bipolar. Segment 1 was released with a mediocaudal approach. Procedure was facilitated by good exposure of operative field with arm 4, stable vision, articulated instrumentation and a "4-hand parenchymal dissection". CONCLUSION: Minimal invasive resection of liver solitary fibrous tumor seems safe and feasible. Because of its advantages compared with laparoscopy, robotic approach could improve accessibility to central tumors liver resection.

Pathological effects of lung radiofrequency ablation that contribute to pneumothorax, using a porcine model.

OBJECTIVES: The incidence of pneumothorax is 7 times higher after lung radiofrequency ablation (RFA) than after lung biopsy. The reasons for such a difference have never been objectified. The histopathologic changes in lung tissue are well-studied and established for RF in the ablation zone. However, it has not been previously described what the nature of thermal injury might be along the shaft of the RF electrode as it traverses through normal lung tissue to reach the ablation zone. The purpose of this study was to determine the changes occurring around the RF needle along the pathway between the ablated zone and the pleura. MATERIAL AND METHODS: In 3 anaesthetised and ventilated swine, 6 RFA procedures (right and left lungs) were performed using a 14-gauge unipolar multi-tined retractable 3 cm radiofrequency LeVeen probe with a coaxial introducer positioned under CT fluoroscopic guidance. In compliance with literature guidelines, we implemented a gradually increasing thermo-ablation protocol using a RF generator. Helical CT images were acquired pre- and post-RFA procedure to detect and evaluate pneumothorax. Four percutaneous 19-gauge lung biopsies were also performed on the fourth swine under CT guidance. Swine were sacrificed for lung ex vivo examinations, scanning electron microscopy (SEM) and pathological analysis. RESULTS: Three severe (over 50 ml) pneumothorax were detected after RFA. In each one of them, pathological examination revealed a fistulous tract between ablation zone and pleura. No fistulous tract was observed after biopsies. In the 3 cases of severe pneumothorax, the tract was wide open and clearly visible on post procedure CT images and SEM examinations. The RFA tract differed from the needle biopsy tract. The histological changes that are usually found in the ablated zone were observed in the RFA tract's wall and were related to thermal lesions. These modifications caused the creation of a coagulated pulmonary parenchyma rim between the thermo-ablation zone and the pleural space. The structural properties of the damage can explain why the RFA tract is remains patent after needle withdrawal. CONCLUSION: Our study demonstrates for the first time that the changes around the RF needle are the same as in the ablated zone. The damage could create fistulous tracts along the needle path between thermo-ablation zone and pleural space. These fistulas could certainly be responsible for severe pneumothorax that occurs in many patients treated with lung RFA.

Appearance of gas collections after scuba diving death: a computed tomography study in a porcine model.

INTRODUCTION: Postmortem computed tomography can easily demonstrate gas collections after diving accidents. Thus, it is often used to support the diagnosis of air embolism secondary to barotrauma. However, many other phenomenons (putrefaction, resuscitation maneuvers, and postmortem tissue offgassing) can also cause postmortem gas effusions and lead to a wrong diagnosis of barotrauma. OBJECTIVES: The aim of this study is to determine topography and time of onset of postmortem gas collections respectively due to putrefaction, resuscitation maneuvers, and tissue offgassing. MATERIALS AND METHODS: A controlled experimental study was conducted on nine pigs. Three groups of three pigs were studied postmortem by CT from H0 to H24: one control group of nonresuscitated nondivers, one group of divers exposed premortem to an absolute maximal pressure of 5 b for 16 min followed by decompression procedures, and one group of nondivers resuscitated by manual ventilation and thoracic compression for 20 min. The study of intravascular gas was conducted using CT scan and correlated with the results of the autopsy. RESULTS: The CT scan reveals that, starting 3 h after death, a substantial amount of gas is observed in the venous and arterial systems in the group of divers. Arterial gas appears 24 h after death for the resuscitated group and is absent for the first 24 h for the control group. Concerning the putrefaction gas, this provokes intravenous and portal gas collections starting 6 h after death. Subcutaneous emphysema was observed in two of the three animals from the resuscitated group, corresponding to the thoracic compression areas. CONCLUSION: In fatal scuba diving accidents, offgassing appears early (starting from the first hour after death) in the venous system then spreads to the arterial system after about 3 h. The presence of intra-arterial gas is therefore not specific to barotrauma. To affirm a death by barotrauma followed by a gas embolism, a postmortem scanner should be conducted very early. Subcutaneous emphysema should not be mistaken as diagnostic criteria of barotrauma because it can be caused by the resuscitation maneuvers.

Prognostic value of preoperative coronary computed tomography angiography in patients treated by orthotopic liver transplantation.

OBJECTIVES: The aim of this study was to assess the feasibility of 64-slice coronary computed tomography (CT) angiography in patients treated by orthotopic liver transplantation, and to compare prognostic values of CT angiography and dobutamine stress echocardiography in the same population. METHODS: Eighty-two consecutive patients, without known coronary artery disease, who underwent orthotopic liver transplantation, were included in this study. A CT angiography was performed along with usual explorations including dobutamine stress echography. A one-year minimal follow-up was performed to seek cardiac events. RESULTS: Fifty-two (65.8%) patients underwent a CT angiography. Thirty-seven (71%) were totally normal or showed nonobstructive coronary plaque, six (12%) showed at least one obstructive coronary plaque greater than 50%. Nine (17%) of the examined patients had at least one nonassessable segment. A total of six (7.6%) major cardiac events occurred in a mean-time follow-up of 17.8 ± 12.7 months. CONCLUSION: CT angiography that is normal or with a nonobstructive coronary plaque has a negative predicting value of 95% [0.82-0.99] for major cardiac adverse events, and of 100% [0.91-1] for clinical coronary events in patients undergoing orthotopic liver transplantation. The prognostic value of CT angiography was comparable with that of dobutamine stress echography.

Measurement of trabeculated left ventricular mass using cardiac magnetic resonance imaging in the diagnosis of left ventricular non-compaction.

AIMS: To describe a method for measuring trabeculated left ventricular (LV) mass using cardiac magnetic resonance imaging and to assess its value in the diagnosis of left ventricular non-compaction (LVNC). METHODS AND RESULTS: Between January 2003 and 2008, we prospectively included 16 patients with LVNC. During the mean period, we included 16 patients with dilated cardiomyopathy (DCM), 16 patients with hypertrophic cardiomyopathy (HCM), and 16 control subjects. Left ventricular volumes, LV ejection fraction, and trabeculated LV mass were measured in the four different populations. The percentage of trabeculated LV mass was almost three times higher in the patients with LVNC (32 +/- 10%), compared with those with DCM (11 +/- 4%, P < 0.0001), HCM (12 +/- 4%, P < 0.0001), and controls (12 +/- 5%, P < 0.0001). A value of trabeculated LV mass above 20% of the global mass of the LV predicted the diagnosis of LVNC with a sensitivity of 93.7% [95% confidence interval (CI), 71.6-98.8%] and a specificity of 93.7% (95% CI, 83.1-97.8%; kappa = 0.84). CONCLUSION: The method described is reproducible and provides an assessment of the global amount of LV trabeculation. A trabeculated LV mass above 20% of the global LV mass is highly sensitive and specific for the diagnosis of LVNC.