In-vivo range verification analysis with in-beam PET data for patients treated with proton therapy at CNAO

Morphological changes that may arise through a treatment course are probably one of the most significant sources of range uncertainty in proton therapy. Non-invasive in-vivo treatment monitoring is useful to increase treatment quality. The INSIDE in-beam Positron Emission Tomography (PET) scanner performs in-vivo range monitoring in proton and carbon therapy treatments at the National Center of Oncological Hadrontherapy (CNAO). It is currently in a clinical trial (ID: NCT03662373) and has acquired in-beam PET data during the treatment of various patients. In this work we analyze the in-beam PET (IB-PET) data of eight patients treated with proton therapy at CNAO. The goal of the analysis is twofold. First, we assess the level of experimental fluctuations in inter-fractional range differences (sensitivity) of the INSIDE PET system by studying patients without morphological changes. Second, we use the obtained results to see whether we can observe anomalously large range variations in patients where morphological changes have occurred. The sensitivity of the INSIDE IB-PET scanner was quantified as the standard deviation of the range difference distributions observed for six patients that did not show morphological changes. Inter-fractional range variations with respect to a reference distribution were estimated using the Most-Likely-Shift (MLS) method. To establish the efficacy of this method, we made a comparison with the Beam’s Eye View (BEV) method. For patients showing no morphological changes in the control CT the average range variation standard deviation was found to be 2.5 mm with the MLS method and 2.3 mm with the BEV method. On the other hand, for patients where some small anatomical changes occurred, we found larger standard deviation values. In these patients we evaluated where anomalous range differences were found and compared them with the CT. We found that the identified regions were mostly in agreement with the morphological changes seen in the CT scan.

The Accuracy of Simple and Adjusted Aldosterone Indices for Assessing Selectivity and Lateralization of Adrenal Vein Sampling in the Diagnosis of Primary Aldosteronism Subtypes

OBJECTIVE

This study aimed to evaluate the reliability of simple and corrected aldosterone indices for assessing the selectivity and lateralization of adrenal vein sampling (AVS) in patients with primary aldosteronism.

METHODS

Data of all consecutive patients with primary aldosteronism who underwent AVS for subtype diagnosis, followed at two Italian referral centers, were analyzed retrospectively.

RESULTS

AVS achieved bilateral selectivity in 112/144 patients. Unilateral disease was diagnosed in 60 cases (53.6%) and idiopathic hyperaldosteronism in 52 individuals (46.4%). The aldosterone index (aldosterone ratio between an adrenal vein and the inferior vena cava) showed a high accuracy in predicting selectivity, compared to a cortisol selectivity index of 1.1, and a moderate accuracy, compared to cortisol cut-offs of 2 and 3. The simple aldosterone index showed a moderate accuracy in predicting ipsi/contralateral aldosterone hypersecretion, while lesion side- and hypokalemia-corrected aldosterone index revealed a significant improvement in predicting ipsi/contralateral disease. Moreover, the comparative aldosterone index (aldosterone ratio in the dominant vs the non-dominant adrenal vein) revealed a high accuracy in predicting unilateral primary aldosteronism. For an immediate clinical application of our results, the adjusted cut-offs were calculated, according to the Youden's criterion and to a pre-established specificity of 90%, for all possible combinations of lesion side at imaging and presence/absence of hypokalemia.

CONCLUSIONS

This study demonstrated the diagnostic accuracy of simple and clinical-/imaging-corrected aldosterone indices for adrenal vein sampling in subtype diagnosis of primary aldosteronism and suggests the potential application of these tools to select patients for adrenalectomy when standard indices cannot be performed.

Localization of anatomical changes in patients during proton therapy with in-beam PET monitoring: A voxel-based morphometry approach exploiting Monte Carlo simulations

Purpose

In‐beam positron emission tomography (PET) is one of the modalities that can be used for in vivo noninvasive treatment monitoring in proton therapy. Although PET monitoring has been frequently applied for this purpose, there is still no straightforward method to translate the information obtained from the PET images into easy‐to‐interpret information for clinical personnel. The purpose of this work is to propose a statistical method for analyzing in‐beam PET monitoring images that can be used to locate, quantify, and visualize regions with possible morphological changes occurring over the course of treatment.

Methods

We selected a patient treated for squamous cell carcinoma (SCC) with proton therapy, to perform multiple Monte Carlo (MC) simulations of the expected PET signal at the start of treatment, and to study how the PET signal may change along the treatment course due to morphological changes. We performed voxel‐wise two‐tailed statistical tests of the simulated PET images, resembling the voxel‐based morphometry (VBM) method commonly used in neuroimaging data analysis, to locate regions with significant morphological changes and to quantify the change.

Results

The VBM resembling method has been successfully applied to the simulated in‐beam PET images, despite the fact that such images suffer from image artifacts and limited statistics. Three dimensional probability maps were obtained, that allowed to identify interfractional morphological changes and to visualize them superimposed on the computed tomography (CT) scan. In particular, the characteristic color patterns resulting from the two‐tailed statistical tests lend themselves to trigger alarms in case of morphological changes along the course of treatment.

Conclusions

The statistical method presented in this work is a promising method to apply to PET monitoring data to reveal interfractional morphological changes in patients, occurring over the course of treatment. Based on simulated in‐beam PET treatment monitoring images, we showed that with our method it was possible to correctly identify the regions that changed. Moreover we could quantify the changes, and visualize them superimposed on the CT scan. The proposed method can possibly help clinical personnel in the replanning procedure in adaptive proton therapy treatments.

"Never Trust to General Impressions, My Boy, but Concentrate Yourself upon Details": An Unusual and Challenging Presentation of Pheochromocytoma

We present the case of a 45-year-old woman admitted to our unit with acute heart failure and cardiogenic shock, requiring an intra-aortic balloon pump insertion and inotropes and vasopressors infusion. Despite such treatment, the patient developed multi organ failure and intravascular disseminated coagulation with haemolysis. The initial diagnosis of acute myocarditis was subsequently denied by the finding of bilateral adrenal masses by MRI scan, and urine and plasma metanephrines measurements confirmed a pheochromocytoma (PCC). Genetic analysis revealed a mutation in the neurofibromatosis type 1 (NF1) gene, and an accurate physical examination drew attention to small cafè-au-lait spots, usually associated with this syndrome. PCC diagnosis should be promptly considered in patients presenting with unexplained acute heart failure and cardiogenic shock of unknown origin, considering its life-threatening complications and the good prognosis after radical surgery.

The diagnostic accuracy of adjusted unconventional indices for adrenal vein sampling in the diagnosis of primary aldosteronism subtypes

OBJECTIVE

Simple unconventional indices did not demonstrate a satisfactory accuracy for diagnosing unilateral primary aldosteronism when adrenal vein sampling is not bilaterally selective. This study aimed to evaluate the reliability of clinical/imaging-corrected unconventional indices for adrenal vein sampling in predicting unilateral primary aldosteronism.

METHODS

Data of all consecutive patients with primary aldosteronism subtyped with adrenal vein sampling, referred to two Italian centers, were analyzed retrospectively. All patients with proved unilateral aldosterone hypersecretion underwent adrenalectomy.

RESULTS

Unilateral disease was diagnosed in 58 cases (54.2%) and idiopathic hyperaldosteronism in 49 individuals (45.8%). The monoadrenal index (aldosterone-to-cortisol ratio in the adrenal vein) showed high accuracy in predicting ipsilateral disease and moderate accuracy in predicting contralateral aldosterone hypersecretion. The monolateral index (aldosterone-to-cortisol ratio in the adrenal vein vs. peripheral blood) revealed moderate accuracy in predicting ipsilateral disease and high accuracy in predicting contralateral aldosterone hypersecretion. Lesion side- and hypokalemia-corrected ROC curves for these unconventional indices revealed a significant improvement in the reliability of predicting ipsilateral/contralateral disease, reaching high accuracy in all models. For an immediate clinical application of our results, the adjusted cut-offs were calculated, according to the Youden's criterion and to a pre-established specificity of 95%, for all possible combinations of lesion side at imaging and presence/absence of hypokalemia.

CONCLUSION

This study demonstrated the high diagnostic accuracy of clinical-/imaging-corrected unconventional indices for adrenal vein sampling in the diagnosis of primary aldosteronism subtypes and suggests the use of these adjusted indices to select patients for adrenalectomy when adrenal vein sampling is not bilaterally selective.

Particle beam microstructure reconstruction and coincidence discrimination in PET monitoring for hadron therapy

Positron emission tomography is one of the most mature techniques for monitoring the particles range in hadron therapy, aiming to reduce treatment uncertainties and therefore the extent of safety margins in the treatment plan. In-beam PET monitoring has been already performed using inter-spill and post-irradiation data, i.e. while the particle beam is off or paused. The full beam acquisition procedure is commonly discarded because the particle spills abruptly increase the random coincidence rates and therefore the image noise. This is because random coincidences cannot be separated by annihilation photons originating from radioactive decays and cannot be corrected with standard random coincidence techniques due to the time correlation of the beam-induced background with the ion beam microstructure. The aim of this paper is to provide a new method to recover in-spill data to improve the images obtained with full-beam PET acquisitions. This is done by estimating the temporal microstructure of the beam and thus selecting input PET events that are less likely to be random ones. The PET detector we used was the one developed within the INSIDE project and tested at the CNAO synchrotron-based facility. The data were taken on a PMMA phantom irradiated with 72 MeV proton pencil beams. The obtained results confirm the possibility of improving the acquired PET data without any external signal coming from the synchrotron or ad hoc detectors.

The Immunological State in Chronic Renal Insufficiency

To evaluate the immunological state in chronic renal insufficiency, the Authors studied cellular and humoral immunity in 292 patients with chronic renal failure.

They were divided into 3 groups: 1) 37 with creatinine clearance between 50 and 20 ml/min; 2) 57 with creatinine clearance between 20 and 8 ml/min; 3) 178 treated by hemodialysis.

In vivo and in vitro tests, that is DNCB, PPD skin tests, spontaneous, active and EAC rosettes, surface membrane immunoglobulin test, complement (C3, C4) and serum immunoglobulins were taken as markers of the immune response.

Cell-mediated immunity was found to be significantly impaired in patients with terminal renal insufficiency or on hemodialysis and also markedly reduced in patients with non-terminal renal insufficiency.

Humoral immunity produced less significant results: the B lymphocyte count and serum immunoglobulins were normal; only C3 levels were found below normal range.

Thus it would seem that cell-mediated immunodeficiency appears in an early stage of chronic renal failure and that hemodialysis does not improve this deficiency.

Online proton therapy monitoring: clinical test of a Silicon-photodetector-based in-beam PET

Particle therapy exploits the energy deposition pattern of hadron beams. The narrow Bragg Peak at the end of range is a major advantage but range uncertainties can cause severe damage and require online verification to maximise the effectiveness in clinics. In-beam Positron Emission Tomography (PET) is a non-invasive, promising in-vivo technique, which consists in the measurement of the β+ activity induced by beam-tissue interactions during treatment, and presents the highest correlation of the measured activity distribution with the deposited dose, since it is not much influenced by biological washout. Here we report the first clinical results obtained with a state-of-the-art in-beam PET scanner, with on-the-fly reconstruction of the activity distribution during irradiation. An automated time-resolved quantitative analysis was tested on a lacrimal gland carcinoma case, monitored during two consecutive treatment sessions. The 3D activity map was reconstructed every 10 s, with an average delay between beam delivery and image availability of about 6 s. The correlation coefficient of 3D activity maps for the two sessions (above 0.9 after 120 s) and the range agreement (within 1 mm) prove the suitability of in-beam PET for online range verification during treatment, a crucial step towards adaptive strategies in particle therapy.

TRIMAGE: A dedicated trimodality (PET/MR/EEG) imaging tool for schizophrenia

Simultaneous PET/MR/EEG (Positron Emission Tomography - Magnetic Resonance - Electroencephalography), a new tool for the investigation of neuronal networks in the human brain, is presented here within the framework of the European Union Project TRIMAGE. The trimodal, cost-effective PET/MR/EEG imaging tool makes use of cutting edge technology both in PET and in MR fields. A novel type of magnet (1.5T, non-cryogenic) has been built together with a PET scanner that makes use of the most advanced photodetectors (i.e., SiPM matrices), scintillators matrices (LYSO) and digital electronics. The combined PET/MR/EEG system is dedicated to brain imaging and has an inner diameter of 260 mm and an axial Field-of-View of 160 mm. It enables the acquisition and assessment of molecular metabolic information with high spatial and temporal resolution in a given brain simultaneously. The dopaminergic system and the glutamatergic system in schizophrenic patients are investigated via PET, the same physiological/pathophysiological conditions with regard to functional connectivity, via fMRI, and its electrophysiological signature via EEG. In addition to basic neuroscience questions addressing neurovascular-metabolic coupling, this new methodology lays the foundation for individual physiological and pathological fingerprints for a wide research field addressing healthy aging, gender effects, plasticity and different psychiatric and neurological diseases. The preliminary performances of two components of the imaging tool (PET and MR) are discussed. Initial results of the search of possible candidates for suitable schizophrenia biomarkers are also presented as obtained with PET/MR systems available to the collaboration.

10-Year Oncologic Outcomes After Laparoscopic or Open Total Mesorectal Excision for Rectal Cancer

BACKGROUND

Only few studies have compared laparoscopic total mesorectal excision (LTME) and open total mesorectal excision (OTME) for rectal cancer with follow-up longer than 5 years. The aim of this study was to compare 10-year oncologic outcomes after LTME and OTME for nonmetastatic rectal cancer.

METHODS

We conducted a retrospective analysis of a prospective database of rectal cancer patients undergoing LTME or OTME. Statistical analyses were performed on an ''intention-to-treat'' basis and by actual treatment. Overall survival (OS) and disease-free survival (DFS) were compared by using the Kaplan-Meier method. A multivariable analysis was performed to identify predictors of poor survival.

RESULTS

Between April 1994 and August 2005, a total of 153 LTME patients and 154 OTME patients were included. Similarly, 10-year OS and DFS after LTME and OTME were observed: 76.8 versus 70.6 % (P = 0.138) and 69.1 versus 67.6 % (P = 0.508), respectively. Conversion to OTME did not adversely affect OS and DFS. Stage-by-stage comparison showed no significant differences between LTME and OTME. No significant differences were observed in local recurrence rates after LTME and OTME (6.5 vs. 7.8 %, P = 0.837). Median time until local recurrence was 24.5 (range, 12-56) months after LTME and 22 (6-64) months after OTME (P = 0.777). Poor tumor differentiation, lymphovascular invasion, and a lymph node ratio of 0.25 or more were the independent predictors of poorer OS and DFS.

CONCLUSION

This retrospective study with long follow-up did not show significant differences between the two groups in OS and DFS.

Full-beam performances of a PET detector with synchrotron therapeutic proton beams

Treatment quality assessment is a crucial feature for both present and next-generation ion therapy facilities. Several approaches are being explored, based on prompt radiation emission or on PET signals by [Formula: see text]-decaying isotopes generated by beam interactions with the body. In-beam PET monitoring at synchrotron-based ion therapy facilities has already been performed, either based on inter-spill data only, to avoid the influence of the prompt radiation, or including both in-spill and inter-spill data. However, the PET images either suffer of poor statistics (inter-spill) or are more influenced by the background induced by prompt radiation (in-spill). Both those problems are expected to worsen for accelerators with improved duty cycle where the inter-spill interval is reduced to shorten the treatment time. With the aim of assessing the detector performance and developing techniques for background reduction, a test of an in-beam PET detector prototype was performed at the CNAO synchrotron-based ion therapy facility in full-beam acquisition modality. Data taken with proton beams impinging on PMMA phantoms showed the system acquisition capability and the resulting activity distribution, separately reconstructed for the in-spill and the inter-spill data. The coincidence time resolution for in-spill and inter-spill data shows a good agreement, with a slight deterioration during the spill. The data selection technique allows the identification and rejection of most of the background originated during the beam delivery. The activity range difference between two different proton beam energies (68 and 72 MeV) was measured and found to be in sub-millimeter agreement with the expected result. However, a slightly longer (2 mm) absolute profile length is obtained for in-spill data when compared to inter-spill data.

INSIDE in-beam positron emission tomography system for particle range monitoring in hadrontherapy

The quality assurance of particle therapy treatment is a fundamental issue that can be addressed by developing reliable monitoring techniques and indicators of the treatment plan correctness. Among the available imaging techniques, positron emission tomography (PET) has long been investigated and then clinically applied to proton and carbon beams. In 2013, the Innovative Solutions for Dosimetry in Hadrontherapy (INSIDE) collaboration proposed an innovative bimodal imaging concept that combines an in-beam PET scanner with a tracking system for charged particle imaging. This paper presents the general architecture of the INSIDE project but focuses on the in-beam PET scanner that has been designed to reconstruct the particles range with millimetric resolution within a fraction of the dose delivered in a treatment of head and neck tumors. The in-beam PET scanner has been recently installed at the Italian National Center of Oncologic Hadrontherapy (CNAO) in Pavia, Italy, and the commissioning phase has just started. The results of the first beam test with clinical proton beams on phantoms clearly show the capability of the in-beam PET to operate during the irradiation delivery and to reconstruct on-line the beam-induced activity map. The accuracy in the activity distal fall-off determination is millimetric for therapeutic doses.

The Thunderbeat and Other Energy Devices in Laparoscopic Colorectal Resections: Analysis of Outcomes and Costs

BACKGROUND

The THUNDERBEAT™ (TB) is a recently developed energy-based device. To date, there are no clinical studies comparing TB and other energy sources, such as standard electrosurgery (ES), ultrasonic coagulating shears (US) and electrothermal bipolar vessel sealers (EBVS) in patients undergoing laparoscopic colorectal resection (LCR). The aim of this study was to compare outcomes and costs in patients undergoing LCR with TB, US, EBVS, or ES for both benign and malignant colorectal diseases.

METHODS

This study is a retrospective analysis of a prospective database of patients undergoing LCR. Unselected consecutive patients who had the laparoscopic dissection conducted by using TB were compared with consecutive patients undergoing LCR with US, EBVS, or ES.

RESULTS

Mean operative time did not significantly differ between the groups (P = .947). Estimated blood loss was significantly higher in the ES group (P < .001). Device-related complications occurred in 2.5% of ES patients, in 2.5% of US patients, and in 5% of EBVS patients, while no complications occurred in TB patients (P = .768). No significant differences were observed in postoperative complication rates between the groups. Mean postoperative hospital stay was similar in the groups. Cost analysis showed no significant differences between US (1519.1 ± 303 €), EBVS (1474.4 ± 372.8 €), and TB (1474.3 ± 176.3 €) (P = .737).

CONCLUSION

This is the first clinical study comparing TB and other energy-based devices in LCR. They all appear to be equally safe and effective. Costs of surgery are very similar. Further large randomized controlled trials are needed to confirm these data.

Issues in the Diagnosis and Treatment of Primary Aldosteronism

Primary aldosteronism (PA) is associated with a high rate of cardio- and cerebrovascular complications and metabolic alterations. PA is also recognized as the most frequent, although often unrecognized, secondary form of hypertension. Guidelines have been released to assist clinicians in the diagnostic work-up and subtype differentiation of PA. In this review we discuss and compare the available guidelines in the context of our professional experience and evaluate diagnostic and therapeutic aspects that are still a matter of debate.

Laparoscopic versus open resection for colon cancer: 10-year outcomes of a prospective clinical trial

BACKGROUND

Laparoscopic resection (LR) and open resection (OR) for colon cancer have similar oncologic outcomes at 5-year follow-up. However, results from studies with longer follow-up are limited. This study aimed to compare 10-year oncologic outcomes of LR and OR for non-metastatic colon cancer.

METHODS

A prospective non-randomized trial comparing patients undergoing LR or OR for non-metastatic colon cancer at a single institution was conducted. Statistical analyses were performed on an ''intention-to-treat'' basis and by actual treatment. Kaplan-Meier curves were compared to analyze overall survival (OS) and disease-free survival (DFS). A multivariate analysis was performed to identify predictors of poor survival.

RESULTS

The study included 304 colon cancer patients: 154 patients underwent LR and 150 underwent OR. Fifteen (9.7 %) had LR converted to OR. During a median follow-up period of 138 (range, 120-220) months, no significant differences were observed between LR and OR patients in 10-year OS and DFS rates: 87.2 % versus 78.7 % (P = 0.182) and 80.9 % versus 76.8 % (P = 0.444), respectively. Conversion to open surgery was associated with a non-significant reduction in OS and DFS. Stage-by-stage comparison showed no significant differences between the two groups. Both OS and DFS were similar between right colon and left-sided colon cancer patients. On multivariate analysis, pT4 cancer and a lymph node ratio of 0.20 or more were the only independent predictors of both OS and DFS.

CONCLUSIONS

The 10-year follow-up results confirm the oncological effectiveness of the laparoscopic approach to non-metastatic colon cancer.

Transanal endoscopic microsurgery vs. laparoscopic total mesorectal excision for T2N0 rectal cancer

OBJECTIVE

The aim was to compare transanal endoscopic microsurgery (TEM) and laparoscopic resection (LR) in terms of short-term and oncologic outcomes in patients with a preoperatively diagnosed T2N0 extraperitoneal rectal cancer.

METHODS

We conducted a retrospective analysis of a prospective database. All patients with a preoperatively staged T2N0 extraperitoneal rectal adenocarcinoma were considered for LR. Patients refusing LR or medically unfit for LR were considered for TEM, which was associated with neoadjuvant RT in the last cases. Only patients with a minimum follow-up of 36 months were included.

RESULTS

Seventy-eight patients were included. TEM was indicated or preferred in 43 patients; of these, 11 underwent neoadjuvant RT. Morbidity was significantly lower after TEM (p < 0.001). The median follow-up was 70 (36-140) months. A higher local recurrence rate was noted after TEM (26 %), compared to neoadjuvant RT + TEM (0 %) and LR (9 %) (p = 0.070). Overall, 5-year survival rate was 76 % after TEM, 77.8 % after RT + TEM, and 96 % after LR, respectively (p = 0.134).

CONCLUSIONS

While TEM alone may only be considered a palliative treatment, it might allow similar oncologic results to abdominal resection in responders to neoadjuvant RT. Large prospective randomized trials are awaited to confirm these findings.

Genes implicated in insulin resistance are down-regulated in primary aldosteronism patients

Primary aldosteronism (PA) patients display an increased incidence of insulin resistance. Herein we demonstrate the decreased gene expression of lipid metabolism genes PCK1, PLIN, ADIPOQ and PPARG in the visceral adipose tissue (VAT) of PA patients compared to age-, sex- and BMI-matched controls. In VAT, the expression of PCK1, PLIN, ADIPOQ and PPARG was inversely correlated with aldosterone levels; furthermore, PLIN and ADIPOQ gene expression was correlated with potassium levels. Therefore, raised aldosterone and low potassium may contribute to the reduced expression of these genes in PA patients. Finally, incubation of primary cultures of human adipocytes with aldosterone resulted in a decrease in the expression of PCK1, PLIN and ADIPOQ and this effect was blocked by eplerenone. Therefore, the characteristic aldosterone excess of PA patients may mediate the down-regulation of PCK1, PLIN and ADIPOQ in VAT that in turn may contribute to the insulin resistance observed in PA patients.

Laparoscopic versus open colorectal resections in patients with symptomatic stage IV colorectal cancer

BACKGROUND

The purpose of this study was to evaluate short-term and oncologic outcomes of laparoscopic resection (LR) for patients with symptomatic stage IV colorectal cancer compared with open resection (OR).

METHODS

This study is a retrospective analysis of a prospective database. Patients with a minimum follow-up of 12 months after LR or OR for metastatic colorectal cancer were included. All analyses were performed on an "intention-to-treat" basis.

RESULTS

A total of 162 consecutive patients submitted to LR and 127 submitted to OR were included. In the LR group, conversion rate was 26.5 %, mostly due to locally advanced disease (88.4 %). A greater risk of conversion was observed among patients with a tumor size greater than 5 cm regardless the tumor site (P = 0.07). Early postoperative outcome was significantly better for LR group, with a shorter hospital stay (P = 0.008), earlier onset of adjuvant treatment, and similar postoperative complications (P = 0.853) and mortality rates (P = 0.958). LR for rectal cancer was associated with a higher morbidity compared with colon cancer (P = 0.058). During a median follow-up time of 72 months, there was no significant difference in overall survival between the two groups (P = 0.622).

CONCLUSIONS

LR for symptomatic metastatic CRC is safe and, compared with OR, is associated with a shorter hospital stay and with similar survival rates. Concerns remain about LR of bulky tumors and rectal cancers due to the increased risk of conversion and postoperative complications.

Centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Charged-particle multiplicity density at midrapidity in central Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ± 76(syst), which corresponds to 8.3 ± 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at √ S NN = 2.76 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.

Midrapidity antiproton-to-proton ratio in pp collisons at sqrt[s]=0.9 and 7 TeV measured by the ALICE experiment

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at sqrt[s]=0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45<p_{t}<1.05  GeV/c and rapidity |y|<0.5. The ratio is measured to be R_{|y|<0.5}=0.957±0.006(stat)±0.014(syst) at 0.9 TeV and R_{|y|<0.5}=0.991±0.005(stat)±0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.

Electrothermal bipolar vessel sealing system vs. harmonic scalpel in colorectal laparoscopic surgery: a prospective, randomized study

PURPOSE

This study was designed to compare the efficacy and safety of laparoscopic colorectal surgery performed with the aid of LigaSure vessel-sealing system or Ultracision.

METHODS

Patients eligible for elective laparoscopic right or left hemicolectomy or anterior resection of rectum were randomly assigned to either the use of Ligasure or Ultracision. The primary end point was intraoperative reduction of blood loss. Secondary end points were intraoperative and postoperative morbidity and operative time.

RESULTS

Between April 2005 and December 2006, 140 consecutive patients were included in the study (70 Ligasure and 70 Ultracision. We performed 31 right hemicolectomies, 69 left hemicolectomies, and 40 anterior resections of rectum. Blood loss was 109.6 ml (Ultracision 107.9 ml vs. Ligasure 111.2 ml, P value = 0.72). Intraoperative complication rate was 2.8 percent (Ultracision 1.4 percent vs. Ligasure 4.2 percent, P value < 0.01). Postoperative mortality was 0.7 percent. The overall conversion rate was 7.8 percent, 6 in the Ligasure group and 5 in the Ultracision group (P value = 0.09). Operative time, considered from pneumoperitoneum to minilaparotomy, was 115.7 minutes (Ultracision 114.8 minutes vs. Ligasure 116.3 minutes, P value = 0.89).

CONCLUSIONS

Results showed that Ligasure and Ultracision are both useful instruments for laparoscopic colorectal surgery with no significant difference in terms of intraoperative/postoperative morbidity and operative time. Choice of which technique to perform should be according to the surgeon's preference.

Roles of clinical criteria, computed tomography scan, and adrenal vein sampling in differential diagnosis of primary aldosteronism subtypes

CONTEXT

In patients with primary aldosteronism (PA), it is fundamental to distinguish between subtypes that benefit from different therapies. Computed tomography (CT) scans lack sensitivity and specificity and must be followed by adrenal venous sampling (AVS). Because AVS is not widely available, a list of clinical criteria that indicate the presence of an aldosterone-producing adenoma (APA) has been suggested.

OBJECTIVE AND DESIGN

The objective of the study was to test the sensitivity and specificity of the last generation CT scans, test prospectively the usefulness of clinical criteria in the diagnosis of APA, and develop a flow chart to be used when AVS is not easily available.

SETTING

Hypertensive patients referred to our hypertension unit were included in our study.

PATIENTS

Seventy-one patients with confirmed PA participated in our study.

INTERVENTION

All patients had a CT scan and underwent AVS.

MAIN OUTCOME MEASURE

Final diagnosis of APA was the main measure.

RESULTS

A total of 44 and 56% of patients were diagnosed as having an APA and a bilateral adrenal hyperplasia (BAH), respectively. Twenty percent of patients with PA displayed hypokalemia. CT scans displayed a sensitivity of 0.87 and a specificity of 0.71. The posture test displayed a lower sensitivity and specificity (0.64 and 0.70, respectively). The distribution grades of hypertension were not significantly different between APA and BAH. Biochemical criteria of high probability of APA displayed a sensitivity of 0.32 and a specificity of 0.95.

CONCLUSIONS

This study underlines the central role of AVS in the subtype diagnosis of PA. The use of the clinical criteria to distinguish between APA and BAH did not display a satisfactory diagnostic power.

Outcome of antegrade continence enema procedures for faecal incontinence in adults

BACKGROUND

Faecal incontinence has major consequences. Colostomy has been the mainstay of therapy when other options fail. Operations such as the Malone procedure have been proposed as an alternative. The aim of this study was to evaluate the outcomes and quality of life of patients having a Malone procedure for the treatment of faecal incontinence.

METHODS

Charts of patients who had had a Malone procedure or equivalent between 1998 and 2004 were reviewed. The patients completed a Short Form (SF) 36 quality of life questionnaire.

RESULTS

The study included 25 patients (17 female; median age 47 years). In seven, the appendix was used; an ileoneoappendicostomy was performed in the other 18. Three patients were lost to follow-up; the remaining 22 were followed for a median (range) of 21 (1-61) months. Five patients had a cutaneous stenosis; another had the appendicostomy removed and replaced by a colostomy. Four patients no longer used the stoma for irrigation. All other patients were completely clean except one, who reported occasional night-time seepage. The mean SF-36 showed a good physical recovery (43.9) but persisting psychological distress (36.0).

CONCLUSION

The Malone procedure or equivalent achieves good results in the management of faecal incontinence, although psychological distress persists after surgery.

Possible impact of autologous blood towards elective open and laparoscopic surgery for colorectal carcinoma

BACKGROUND/AIMS

An alternative approach to the allogeneic transfusion is patient's blood collection before the operation, using or not using the human recombinant erythropoietin. The aim of this study is to evaluate the percentage of people undergoing an elective operation for colorectal carcinoma who could avoid allogeneic blood due to blood predonation.

METHODOLOGY

From January 1999 to April 2002, 249 patients (140 males and 109 females) underwent an operation for colorectal cancer. The most important parameter, used to estimate which patients are candidates for autologous blood predonation, is the before-treatment hemoglobin level. The other parameters we considered are the age of the patient, the absence of uncontrolled hypertension or clinically significant pathologies (except colorectal cancer), and the iron shortage.

DESIGN

Retrospective cohort study.

RESULTS

36.5% of the patients satisfied every criterion to begin autologous predonation without using the human recombinant erythropoietin; instead, 23.7% of patients needed the administration of the human recombinant erythropoietin and additional iron. The valuation of the transfusional prospects, based on sex and cancer location is very interesting.

CONCLUSIONS

Autologous blood predeposit in preoperational time turns out to be a method of increasing importance, thanks to the human recombinant erythropoietin.

Ultrasonic versus standard electric dissection in laparoscopic colorectal surgery: a prospective randomized clinical trial

OBJECTIVE

To assess the safety and efficacy of the ultrasonic dissection (UC) compared with standard electrosurgery (ES) in laparoscopic colorectal surgery.

BACKGROUND DATA

High-frequency ultrasound energy was introduced in laparoscopic surgery to improve dissection and coagulation. Very limited data have been published on its use in laparoscopic colorectal surgery.

METHODS

Patients eligible for elective laparoscopic right or left hemicolectomy (RH and LH), sigmoidectomy (SG), or low anterior resection (LAR) were randomized to either UC or ES. The following data were collected and analyzed: preoperative data (individual patient data, indication for surgery), intraoperative data (conversion to open surgery, conversion ES to UC, operative time, blood loss, complication rate), and postoperative data (morbidity and mortality, volume of drainage, hospital stay).

RESULTS

Between January 2002 and December 2003, 171 patients underwent elective laparoscopic colorectal resection. Twenty-5 patients did not satisfy the inclusion criteria and were excluded. The diagnosis of the remaining 146 patients was diverticulitis (44), colonic adenoma (31), adenocarcinoma (70), or epidermoid carcinoma (1). These patients underwent laparoscopic RH (28), LH (31), SG (47), or LAR (40). There were no differences in preoperative data. The overall conversion rate to open surgery was 11.6%, with no differences between the two groups; 20.8% undergoing ES were converted to UC, more frequently during right hemicolectomy or low anterior resection. Operative time, the primary endpoint of this study, did not differ between the two groups: UC 93 minutes versus ES 102.6 minutes (P = 0.46). Intraoperative blood loss was significantly less in UC 140.8 mL versus ES 182.6 mL (P = 0.032). No differences were observed in postoperative morbidity or other preoperative or postoperative parameters.

CONCLUSIONS

UC is a useful device in laparoscopic colorectal surgery that facilitates completion of difficult cases and reduces intraoperative blood loss. Nevertheless, the majority of laparoscopic procedures can be completed with ES. Therefore, selective use of UC appears to be the most cost-effective policy.

Laparoscopic versus open surgery for extraperitoneal rectal cancer: a prospective comparative study

BACKGROUND

The role of laparoscopic resection (LR) in the management of extraperitoneal rectal cancer still is unclear. This study aimed to compare perioperative and long-term results of laparoscopic and open resection (OR) for low and midrectal cancer.

METHODS

A prospective nonrandomized trial comparing patients submitted to OR or LR for low and midrectal cancer at a single institution was conducted.

RESULTS

The study included 191 consecutive patients: 98 patients who underwent LR and 93 who underwent OR. The mean follow-up period was 46.3 months for LR and 49.7 months for OR. The conversion rate for LR was 18.4%. With the use of LR, the mean time for complete patient mobilization was shorter (1.7 vs 3.3 days; p < 0.001) and patients were earlier in passing flatus (2.6 vs 3.9 days; p < 0.001) and stools (3.8 vs 4.7 days; p < 0.01), and in resuming oral intake (3.4 vs 4.8 days; p < 0.001). The mean hospital stay was shorter for LR, but the difference did not reach significance (11.4 vs 13 days). Morbidity and mortality rates were similar: LR (24.4% and 1%) and OR (23.6% and 2.2%). Laparoscopic patients presented a higher rate of anastomotic fistulas (13.5% vs 5.1%) and reoperations (6.1% vs 3.2%) but the difference was statistically nonsignificant. Laparoscopic resection presented a significantly lower local recurrence rate (3.2% vs 12.6%; p < 0.05). The cumulative survival and disease-free rates at 5 years were, respectively, 80% and 65.4% after LR and 68.9% and 58.9% after OR (nonsignificant difference). Stage-by-stage comparison showed prolonged cumulative survival for stages III and IV cancer in LR (82.5% vs 40.5%; p = 0.006 and 15.8% vs 0%; p = 0.013, respectively) and a reduced rate of cancer-related death for stage III in LR (11.4% vs 51.9%; p = 0.001).

CONCLUSIONS

As compared with conventional open surgery, LR for low and midrectal cancer is characterized by a faster recovery and similar overall morbidity (but a higher rate of anastomotic leakages), and does not present any adverse oncologic effect.

Laparoscopic total mesorectal excision-the Turin experience

Improved local control and survival rates in the treatment of rectal cancer have been reported after total mesorectal excision (TME). We performed an analysis of TME for rectal cancer by laparoscopic approach during a prospective nonrandomized trial. A prospective consecutive series of 98 laparoscopic total mesorectal excision (LTME) procedures for low and mid-rectal tumors. All patients had a sphincter-saving procedure. Case selection, surgical technique, and clinical and oncological results were reviewed. The distal limit of rectal neoplasm was on average 5.4 cm (range 3-12) from the anal verge. The mean operative time was 192.5 min (range 125-360). The conversion rate was 18.4%. The mean postoperative stay was 11.6 days (range 4-61). The 30-day mortality rate was 1% (1/98) and the overall postoperative morbidity was 18.4% including 10 anastomotic leakages. Concerning long-term oncological results, we evaluated 93 (94.8%) patients with a median follow-up of 46.3 months (range 12-132). During this period, 15.1% (14/93) died of cancer and 7.5% (7/93) are alive with metastatic disease. The port-site metastases rate was 2.1% (2/93). The locoregional pelvic recurrence rate was 2.1% (2/93): 1 stage II at 12 months and 1 stage III at 18 postoperative months, respectively. LTME is a feasible but technically demanding procedure (18.4% conversion rate). Our series confirms the safety of the procedure, while oncological results are at present comparable to the open published series with the limitation of a short follow-up period. Further studies and possibly randomized series will be necessary to evaluate long-term clinical outcome in cancer patients.

Is laparoscopic adrenalectomy feasible for adrenocortical carcinoma or metastasis?

OBJECTIVE

To review our experience with laparoscopic adrenalectomy (LA), to evaluate the effectiveness and safety of this procedure in patients with adrenal malignancy.

PATIENTS AND METHODS

The study included patients who underwent LA from 1995 to 2002, with histologically identified adrenocortical cancer (ACC) or metastasis. Indications for LA were adrenal masses with no radiological evidence of involvement of the surrounding structures, or solitary metastasis with well-controlled primary cancer. The variables evaluated were: size of the lesion, operative duration, estimated blood loss, intraoperative complications, local, port-site and intra-abdominal recurrence, distant metastasis, and survival time.

RESULTS

Fourteen malignant adrenal lesions in 205 LAs (7%) were confirmed with histological diagnoses that showed a primary ACC in six and metastasis in another seven (in one there was bilateral metastasis). The mean (sd) size of the malignant lesions was 5.9 (2.8) cm. The 12 unilateral procedures required a mean operative duration of 164 (47) min; the bilateral procedure lasted 215 min. There was one conversion to open surgery caused by local infiltration, whereas there were no intraoperative complications. The mean follow-up was 30 months, during which three patients died, one from endoperitoneal and trocar port-site seeding.

CONCLUSION

When the malignancy is confined to the adrenal gland, LA seems to be a feasible option if the principles of oncological surgery are respected. Nevertheless, further investigations are required to evaluate the appropriateness of this operation.

Robot-assisted vs laparoscopic adrenalectomy: a prospective randomized controlled trial

BACKGROUND

The aim of this study was to assess the benefits and disadvantages of robot-assisted laparoscopic surgery for disorders of the adrenal gland in terms of feasibility, safety, and length of hospitalization.

METHODS

Twenty consecutive patients with benign lesions of adrenal gland were randomized into two groups: Patients in the laparoscopic group underwent traditional laparoscopic adrenalectomy (LAP), whereas those in the robotic group underwent robot-assisted adrenalectomy (ROBOT) using the da Vinci robotic system.

RESULTS

There was no significant difference between the groups in terms of age, sex, body mass index, and size or locations of lesions. Operative times were significant longer in the ROBOT group (total operative time, 169.2 min [range, 136-215] vs 115.3 min (range, 95-155) p < 0.001. Skin-to-skin time was 107 m (range, 77-154) vs 82.1 min (range, 55-120) (p < 0.001). There were no conversions to open surgery. However, conversion to standard laparoscopic surgery was necessary in four of 10 ROBOT patients (40%; left, one right). Perioperative morbidity was higher in the ROBOT group (20% vs 0%). There was no difference in length of hospital stay. In the following ROBOT group, hospital stay was 5.7 days (range, 4-9) vs 5.4 days (range, 4-8) in the LAP group (p = NS). The total cost of the ROBOT procedure ($3,467) was significantly higher than that for LAP ($2,737) (p < 0.01).

CONCLUSION

Laparoscopic adrenalectomy is superior to robot-assisted adrenalectomy in terms of feasibility, morbidity, and cost.

[Laparoscopic adrenalectomy in multiple endocrine tumors, in secreting and non-secreting lesions]

AIM

Personal experience in laparoscopic adrenalectomies (LA) for secreting and non-secreting tumors is presented.

METHODS

Between March 1995 and December 2001 a total of 111 LA (58 left, 49 right and 4 bilateral) were performed in 60 females and 51 males, mean age 47.5 (range 8-81) years, for: 38 Conn diseases, 24 incidentalomas, 15 pheochromocytomas, 13 Cushing diseases, 4 kysts, 3 angiomyolipomas, 1 adreno-genital syndrome, 1 hydatidosis, 1 hyperplasia, 1 ganglioneuroma, 1 oncocyte adenoma, 1 adrenal fibrous tumor, 4 cortical carcinomas and 4 metastases (from renal carcinoma, breast carcinoma, leiomyosarcoma and rabdoid sarcoma, respectively). In all cases LA was transabdominal with a lateral flank approach.

RESULTS

Mean global operative time was 88.6 minutes (range 35-240). Conversion rate was 1.8% (2/111). There was low postoperative pain. Mean hospital stay was 4.3 days (range 2-13). There were 0.9% (1/111) 30-day mortality and 4.5% (5/111) morbidity. During a mean follow-up of 41 months (range 1-81), the 67 secreting patients were disease-free. Concerning 8 malignant cases, mean follow-up was 40.5 months (range 9-72) with 3 cortical carcinomas disease-free and 1 dead for stroke, 2 metastases (1 leiomyosarcoma and 1 breast carcinoma) dead for disease and 2 disease-free. There was no port-site metastases.

CONCLUSIONS

LA seems safe and effective when performed in experienced Centers on endocrine surgery and laparoscopy.

Laparoscopic total mesorectal excision: a consecutive series of 100 patients

OBJECTIVE

To analyze total mesorectal excision (TME) for rectal cancer by the laparoscopic approach during a prospective nonrandomized trial.

SUMMARY BACKGROUND DATA

Improved local control and survival rates in the treatment of rectal cancer have been reported after TME.

METHODS

The authors conducted a prospective consecutive series of 100 laparoscopic TMEs for low and mid-rectal tumors. All patients had a sphincter-saving procedure. Case selection, surgical technique, and clinical and oncologic results were reviewed.

RESULTS

The distal limit of rectal neoplasm was on average 6.1 (range 3-12) cm from the anal verge. The mean operative time was 250 (range 110-540) minutes. The conversion rate was 12%. Excluding the patient who stayed 104 days after a severe fistula and reoperation, the mean postoperative stay was 12.05 (range 5-53) days. The 30-day mortality was 2% and the overall postoperative morbidity was 36%, including 17 anastomotic leaks. Of 87 malignant cases, 70 (80.4%) had a minimum follow-up of 12 months, with a median follow-up of 45.7 (range 12-72) months. During this period 18.5% (13/70) died of cancer and 8.5% (6/70) are alive with metastatic disease. The port-site metastasis rate was 1.4% (1/70): a rectal cancer stage IV presented with a parietal recurrence at 17 months after surgery. The locoregional pelvic recurrence rate was 4.2% (3/70): three rectal cancers stage III at 19, 13, and 7 postoperative months.

CONCLUSIONS

Laparoscopic TME is a feasible but technically demanding procedure (12% conversion rate). This series confirms the safety of the procedure, while oncologic results are at present comparable to the open published series with the limitation of a short follow-up period. Further studies and possibly randomized series will be necessary to evaluate long-term clinical outcome in cancer patients.

Does adrenal mass size really affect safety and effectiveness of laparoscopic adrenalectomy?

OBJECTIVES

To evaluate the effectiveness and safety of laparoscopic adrenalectomy with regard to adrenal mass size, as well as to consider its clinical and pathologic patterns. Laparoscopy is today considered the first-choice treatment of many adrenal diseases, although its use is still controversial for large adrenal masses and incidentally found adrenal cortical carcinoma.

METHODS

A total of 125 patients underwent lateral transperitoneal laparoscopic adrenalectomy. The indications were either functioning or nonfunctioning adrenal masses, without any radiologic evidence of involvement of the surrounding structures. The correlation between the size and the operative times, estimated blood loss, incidence of intraoperative and postoperative complications, and length of hospital stay were studied with Pearson's correlation coefficient, Fisher's exact test, and the chi-square test. The analysis of variance test was used to evaluate any possible correlation between the size and clinicopathologic features and the results.

RESULTS

A slight correlation was observed between the size and operative time (P = 0.004), but no correlation was observed between the size and the other parameters. Statistical analysis showed a significant correlation between the clinicopathologic patterns (nonfunctioning benign adrenal masses, Conn's adenoma, Cushing's adenoma, pheochromocytoma, adrenal cortical cancer, and other tumor metastasis) and the operative time (P = 0.011), but not with the other parameters.

CONCLUSIONS

Laparoscopic adrenalectomy is also effective and safe for large lesions. The results of our series confirms that the risk of encountering an incidental adrenal cortical cancer is significantly increased for large lesions, and therefore, in these cases, additional attention is required to observe oncologic surgical principles.

Abdominal wall recurrences after colorectal resection for cancer: results of the Italian registry of laparoscopic colorectal surgery

PURPOSE

The purpose of the present study was to evaluate prospectively the abdominal wall recurrence rate after laparoscopic resection for colorectal cancer, to analyze the impact of the learning curve on abdominal wall recurrence, and to assess the outcome of those patients.

METHODS

The Italian Registry of Laparoscopic Colorectal Surgery database was analyzed to obtain data on cancer patients with abdominal wall recurrence, concomitant local or distant metastases, and interval between initial surgery and diagnosis of trocar site or minilaparotomy recurrences. The records of the initial procedures and the technique of specimen removal were reviewed.

RESULTS

From January 1992 to July 2000, 2,583 patients (1,753 cases of carcinomas and 830 cases of benign diseases) were recorded. The malignant lesions were located on the right colon in 19 percent, the left colon in 48.8 percent, and rectum in 32.2 percent. Sixteen patients with histologic evidence of colorectal adenocarcinoma recurrences at the abdominal wall were observed (0.9 percent). Ten patients presented an advanced stage (III for 7 patients and IV for 3 patients). Eleven cases occurred during the learning curve period (the first 50 consecutive cases). The median survival time after abdominal wall recurrence diagnosis was 16 (range, 12-60) months. By July 2000 only two patients were alive.

CONCLUSIONS

The results of the Italian prospective Registry of Laparoscopic Colorectal Surgery confirm that the incidence of abdominal wall recurrences is similar to that reported in open studies (<1 percent). Most abdominal wall recurrences occurred in the learning curve period, suggesting that surgical experience may play a role in the development of this outcome. The prognosis of these patients is very poor.

Safe retroperitoneal endoscopic resection of pheochromocytomas

Although endoscopic adrenalectomy is advocated for small adrenocortical tumors, questions remain about the safety of endoscopic retroperitoneal resection of pheochromocytomas. In this study we evaluated the outcome of retroperitoneal endoscopic adrenalectomy for pheochromocytoma. Between June 1995 and September 1999 we performed 18 retroperitoneal endoscopic adrenalectomies for a pheochromocytoma or paraganglioma. All patients received adequate alpha-adrenergic blockade. The adrenal vein was ligated at the end of the procedure. Operative blood pressure values were recorded and evaluated. Altogether 15 patients (11 women, 4 men; mean age 47.2 years) were operated on for 17 pheochromocytomas and 1 extraadrenal tumor (4 right, 11 left, 3 bilateral). One female patient was operated on at 13 weeks' gestation. Hypertensive episodes at operation were seen in 4 (26.7%) patients, and tachycardia occurred in 5 (33%). Hemodynamic changes could be corrected in all cases using simple measures without morbidity or detrimental effects. The mean operating time was 125 minutes (80-180 minutes), and the conversion rate was 5.6% (1/18). The median hospital stay was 5 days (3-28 days). Morbidity was 20% (3/15). Endoscopic retroperitoneal adrenalectomy for pheochromocytoma is safe and effective, and it is associated with limited morbidity.

Gasless laparoscopy could avoid alterations in hepatic function

BACKGROUND

In a previous clinical study, we showed that the duration and level of pneumoperitoneum are responsible for changes in hepatic function during laparoscopic procedures. These findings encouraged us to evaluate hepatic function during laparoscopy with and without carbon dioxide (CO(2)) pneumoperitoneum in a clinical setting.

METHODS

We performed 63 laparoscopic cholecystectomies and 30 non-hepatobiliary laparoscopic procedures in 93 consecutive patients with normal preoperative liver function tests. The anesthesiologic protocol was uniform, using drugs at low hepatic metabolism. We performed laparoscopic cholecystectomies in 43 patients with a pneumoperitoneum; in the remaining 20, we used a gasless technique. We randomized the 43 laparoscopic cholecystectomies into 23 performed with pneumoperitoneum at 14 mmHg and 20 performed at 10 mmHg. All non-hepatobiliary laparoscopic procedures were performed with a pneumoperitoneum of 14 mmHg. The postoperative serologic levels of AST, ALT, and bilirubin, and the prothrombin time were measured at 6, 24, 48, and 72 h. The alterations in the serologic hepatic tests were then related to the type of procedure, its duration, and the level of pneumoperitoneum.

RESULTS

The study group was comprised of 93 patients, 39 male and 54 female, with a mean age of 50.5 years (range, 15-74). There were no deaths. There was no morbidity in the pneumoperitoneum group, but there was one case of accidental omental injury during the placement of the abdominal, wall retractor in the gasless group. All patients had postoperative changes in serologic hepatic tests. Slow return to normality occurred 48 or 72 h after the operation. The increase in AST and ALT was statistically significant and correlated to the level and duration of pneumoperitoneum. The serologic change in the gasless group were significantly lower than in the laparoscopic cholecystectomy group with pneumoperitoneum at 14 mmHg. There was no statistically significant difference between the gasless group and the laparoscopic cholecystectomy group with pneumoperitoneum at 10 mmHg. There was a statistically the significant increase in the non-hepatobiliary laparoscopy group over the gasless group, despite the absence of hepatobiliary injuries in the first group. No symptoms were related to these serologic hepatic changes.

CONCLUSIONS

The gasless technique causes smaller alterations in serological hepatic parameters than pneumoperitoneum at 14 mmHg. By contrast, the gasless technique and low-pressure pneumoperitoneum have the same effect on hepatic function. Therefore, the use of a subcutaneous abdominal wall retractor combined with a low-pressure pneumoperitoneum is recommended for patients with severe hepatic failure. Transaminases