Syngas biomethanation: In a transfer limited process, is CO inhibition an issue?

Syngas biomethanation is a promising technology in the process chain converting wastes to methane. However, gas-liquid mass transfer is a limiting factor of the biomethanation process. To reach high methane productivity, increasing the pressure is an interesting strategy to improve mass transfer. However, the CO content in the syngas raises concerns about a potential inhibition of the microorganisms. Therefore, the aim of the research was to assess the ability to work at high CO partial pressures. In this regard, a pressurized continuous stirred column with a working volume of 10L was implemented and a consortium adapted for syngas-biomethanation for 22 months was submitted to 100% CO and increasing pressure. No inhibition phenomenon was observed for logarithmic P_CO as high as 1.8 bar (inlet pressure 5.0 bar), which was the first time that such a high CO partial pressure was tested in continuous mode. Mass transfer limitations allowed for the carboxydotrophic microorganisms to consume CO faster than it was transferred, allowing for the dissolved CO concentration to remain under inhibitory concentrations. These results question the habitual consensus that CO inhibition is a limiting factor of syngas biomethanation.

Syngas biomethanation: Study of process performances at high syngas flow rate in pressurized stirred column

Syngas biomethanation is a promising technology for waste to energy conversion. However, it had not yet been tested at high syngas flow rates. The aim of this study was to assess the possibility for syngas biomethanation to reach high methane productivity at higher syngas inflow rate. A pressurized stirred column was implemented. The syngas inflow rate was gradually increased, and two different increase strategies were compared. The highest methane productivity achieved yet with syngas-biomethanation was obtained, with 23.2 L_CH4/L/d, with high conversion efficiencies of 89% for H₂ and 82% for CO. The mass transfer performances of the process were investigated, and the existence of a biological enhancement factor was observed. Considering an enhancement factor in bioprocesses is a pioneering concept that could change the way we design bioreactor to improve mass transfer. The high methane productivity obtained in this study paves the way for the process industrialization.

Pectoralis Major Muscle Belly Rupture in a 17-Year-Old Female Softball Player: A Case Report

CASE

We report the case of a healthy 17-year-old female softball player with a subacute full-thickness intramuscular tear of the pectoralis major (PM) muscle. A successful muscle repair was obtained using a modified Kessler technique.

CONCLUSIONS

Despite initially being a rare injury pattern, the incidence of PM muscle rupture is likely to increase as interest in sports and weight training increases, and although this injury pattern is more common in men, it is becoming more common in women as well. Furthermore, this case presentation provides support for operative treatment of intramuscular ruptures of the PM muscle.

Augmentation of Arthroscopic Rotator Cuff Repair With Cannulated Dermal Allograft Implant

Arthroscopic rotator cuff repair (RCR) is a popular treatment for rotator cuff tears. Retear after RCR remains a significant concern even with modern techniques. Augmentation of RCR has been described using multiple different grafts, one option including a cannulated dermal allograft implant (DePuy Mitek). The utilization of this implant avoids significantly increased surgical time, allows for augmentation at the weakest area of repair, and does not lead to any wasted allograft material.

Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) R47H Variant Causes Distinct Age- and Sex-Dependent Musculoskeletal Alterations in Mice

Previous studies proposed the Triggering Receptor Expressed on Myeloid Cells 2 (TREM2), a receptor expressed in myeloid cells including microglia in brain and osteoclasts in bone, as a link between brain and bone disease. The TREM2 R47H variant is a known risk factor for Alzheimer's disease (AD), the most common form of dementia. To investigate whether altered TREM2 signaling could contribute to bone and skeletal muscle loss, independently of central nervous system defects, we used mice globally hemizygous for the TREM2 R47H variant (TREM2R47H/+ ), which do not exhibit AD pathology, and wild-type (WT) littermate control mice. Dxa/Piximus showed bone loss in female TREM2R47H/+ animals between 4 and 13 months of age and reduced cancellous and cortical bone (measured by micro-computed tomography [μCT]) at 13 months, which stalled out by 20 months of age. In addition, they exhibited decreased femoral biomechanical properties measured by three-point bending at 13 months of age, but not at 4 or 20 months. Male TREM2R47H/+ animals had decreased trabecular bone geometry but increased ultimate strain and failure force at 20 months of age versus WT. Only male TREM2R47H/+ osteoclasts differentiated more ex vivo after 7 days with receptor activator of nuclear factor κB ligand (RANKL)/macrophage colony-stimulating factor (M-CSF) compared to WT littermates. Yet, estrogen receptor alpha expression was higher in female and male TREM2R47H/+ osteoclasts compared to WT mice. However, female TREM2R47H/+ osteoclasts expressed less complement 3 (C3), an estrogen responsive element, and increased protein kinase B (Akt) activity, suggesting altered estrogen signaling in TREM2R47H/+ cells. Despite lower bone volume/strength in TREM2R47H/+ mice, skeletal muscle function measured by plantar flexion and muscle contractility was increased in 13-month-old female mutant mice. Overall, these data demonstrate that an AD-associated TREM2 variant can alter bone and skeletal muscle strength in a sex-dimorphic manner independent of central neuropathology, potentially mediated through changes in osteoclastic intracellular signaling. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Arthroscopy Should be Used With Caution for Gunshot Wounds to the Hip

Purpose

To evaluate the safety and efficacy of hip arthroscopy immediately following gunshot wound (GSW) to the hip.

Methods

Patients who received hip arthroscopy for GSWs from 2006 to 2020 by 2 surgeons at a level I trauma center were identified by Current Procedural Terminology codes. Inclusion criteria were those patients who suffered a GSW to the hip, received hip arthroscopy for treatment, and had a minimum follow-up of 2 months. The exclusion criteria were any patients younger than 18 years of age. Medical records were reviewed for patient demographics, surgical details, clinical outcomes, and complications.

Results

A total of 50 hip arthroscopy cases were identified by Current Procedural Terminology codes. Of the 50 cases identified, 8 patients met the inclusion criteria. All 8 patients were male, African-American, and the mean age was 31 years (range, 19-54 years) with mean follow-up of 14 months. Five of 8 cases were noted to have poor visualization with arthroscopy. Common reasons for poor visualization were difficult access to the bullet fragments, morbid obesity, hematoma formation, and pre-existing arthritis. Of these 5 cases, 2 were converted to open procedures to retrieve the remaining bullet fragments. One patient developed abdominal compartment syndrome, most likely due to increased pulse pressure over a prolonged operative period and involvement of the acetabular fovea. Emergent exploratory laparotomy and abdominal compartment fluid release were performed, and the patient had an otherwise unremarkable hospital course.

Conclusions

There are risks with the use of arthroscopic methods to remove GSW fragments, which may be greater than elective hip arthroscopy. Certain factors, such as the surgeon’s arthroscopic experience, locations of bullets fragments, visual quality, length of procedure, and concomitant acetabular fractures, must be considered before proceeding with arthroscopy.

Level of Evidence

Therapeutic case series.

Seasonal differences in emergency department visits for scooter associated injuries

Hoverboards and electric scooters have surged in popularity in the past decade. These devices carry their own injury profiles and have caused increasing emergency department visits for injury. The purpose of this study was to compare both hoverboards and electric scooters to more traditional scooters and evaluate seasonal variations in their injury patterns. The National Electronic Injury Surveillance System (NEISS) database was used, downloading cases with the appropriate consumer product codes. Four distinct scooter groups were created, and were: non-powered scooters, powered scooters, electric scooters, and hoverboards. Statistical analyses were first performed with SUDAAN software to account for the stratified and weighted nature of the data to obtain national estimates of injuries and associated demographic variables. Cosinor analyses were performed to analyze the estimated number of emergency department (ED) visits for rhythmic variation by month and weekday of injury. Weekday by month analyses were studied using a three-dimensional topographic concept. Overall, there were over 1 million ED visits over the 20 years for injuries due to the four different types of scooters (75.8% nonmotorized scooters, 12.4% motorized scooters, 6.8% hoverboards, and 2.4% electric scooters). Cosinor analyses demonstrated that there was a peak in injuries in the summer and on weekends for all scooters, except for hoverboards. For hoverboards 21% of all ED visits occurred in December, with mostly occurring exactly around Christmas Day. This study confirms previous findings that scooter injuries occur mostly in warmer months and is the first to demonstrate a topographical "Christmas Effect" of hoverboard injuries. This information can be used in health care resource allocation as well as design of potential prevention strategies.

"Biomethanation of syngas by enriched mixed anaerobic consortium in pressurized agitated column"

In a circular economy approach, heterogeneous wastes can be upgraded to energy in the form of syngas via pyrogasification, and then to methane via biomethanation. Working at high pressure is a promising approach to intensify the process and to reduce gas-liquid transfer limitations. However, raising the pressure could lead to reaching the CO inhibition threshold of the microorganisms involved in syngas-biomethanation. To investigate the impact on pressure on the process, a 10L continuous stirred tank reactor working at 4 bars and 55 °C was implemented. Syngas (40% CO, 40% H₂, 20% CO₂) biomethanation was performed successfully and methane productivity as high as 6.8 mmol_CH4/L_reactor/h with almost full conversion of CO (97%) and H₂ (98%) was achieved. CO inhibition was investigated and carboxydotrophs appeared less resistant to high CO exposition than methanogens.

Working toward a common HSPA framework

HSPA has been viewed by international organisations, including the WHO, as primarily a country-specific process for which there is no single accepted template. As a result, while HSPA efforts generally agree on the basics, the practice of their application for assessing health systems varies depending on the methodology of a specific approach, capacity to conduct a comprehensive evaluation, as well as on county context.

The UHC2030 Technical Working Group sought to examine the similarities and differences across various tools used to carry out health system assessment to make use of the information they collect in a more harmonised and performance-focussed way. This was done through a rigorous review of existing tools and frameworks, as well as through conceptual work on further development of HSPA process to link health system functions and sub-functions to performance across specific assessment areas, intermediate health system objectives and final goals.

This presentation will provide an overview of the approach taken to harmonise the existing tools, which led to the creation of the HSPA framework for UHC. It will introduce the methodology and the basic analytical framework, and put this work into a wider context of the role of health systems.

Oncological strategies for locally advanced rectal cancer with synchronous liver metastases, interval strategy versus rectum first strategy: a comparison of short-term outcomes

BACKGROUND

The goal of treatment for patients with synchronous liver metastases (SLM) from rectal cancer is to achieve a complete resection of both tumor locations. For patients with symptomatic locally advanced rectal cancer with resectable SLM at diagnosis, our usual strategy has been the rectum first approach (RF). However, since 2014, we advocate for the interval approach (IS) that involves the administration of chemo-radiotherapy followed by the resection of the SLM in the interval of time between rectal cancer radiation and rectal surgery.

METHODS

From 2010 to 2016, 16 patients were treated according to this new strategy and 19 were treated according RF strategy. Data were collected prospectively and analyzed with an intention-to-treat perspective. Complete resection rate, duration of the treatment and morbi-mortality were the main outcomes.

RESULTS

The complete resection rate in the IS was higher (100%, n = 16) compared to the RF (74%, n = 14, p = 0.049) and the duration of the strategy was shorter (6 vs. 9 months, respectively, p = 0.006). The incidence of severe complications after liver surgery was 14% (n = 2) in the RF and 0% in the IS (p = 1.000), and after rectal surgery was 24% (n = 4) and 12% (n = 2), respectively (p = 1.000).

CONCLUSION

The IS is a feasible and safe strategy that procures higher level of complete resection rate in a shorter period of time compared to RF strategy.

Long-term outcomes of patients with 10 or more colorectal liver metastases

BACKGROUND

Although the number of colorectal liver metastases (CLM) is decreasingly considered as a contraindication to surgery, patients with 10 CLM or more are often denied liver surgery. This study aimed to evaluate the outcome after liver surgery and to identify prognostic factors of survival in such patients.

METHODS

The study population consisted of a multicentre cohort of patients with CLM (N=12 406) operated on, with intention to resect, from January 2005-June 2013 and whose data were prospectively collected in the LiverMetSurvey registry.

RESULTS

Overall, the group ⩾10 CLM (N=529, 4.3%) experienced a 5-year overall survival (OS) of 30%. A macroscopically complete (R0/R1) resection (72.8% of patients) was associated with a 3- and 5-year OS of 61% and 39% vs 29% and 5% for R2/no resection patients (P<0.0001). At multivariate analysis, R0/R1 resection emerged as the strongest favourable factor of OS (HR 0.35 (0.26-0.48)). Other independent favourable factors were as follows: maximal tumour size <40 mm (HR 0.67 (0.49-0.92)); age <60 years (HR 0.66 (0.50-0.88)); preoperative MRI (HR 0.65 (0.47-0.89)); and adjuvant chemotherapy (HR 0.73 (0.55-0.98)). The model showed that 5-year OS rates of 30% was possible provided R0/R1 resection associated with at least an additional favourable factor.

CONCLUSIONS

Liver resection might provide long-term survival in patients with ⩾10 CLM staged with preoperative MRI, provided R0/R1 resection followed by adjuvant therapy. A validation of these results in another cohort is needed.

Faux Pas: Assessing Theory of Superior Mind. A Control-case Study

Often, children with autism spectrum disorder (ASD) can present deficits for acquiring superior level of theory of mind (ToM) in the detection of false beliefs o blunder situations. The objective of this study is to assess 51 subjects with a primary education level (18 with ASD compared to 33 control subjects) comparing ToM level by using the test of Faux Pas test by Baron-Cohen et al. (1999) in two groups divided in 2 layers by age of 7 and 11 years. Results showed significant differences in this construct (ToM) between control group and ASD group only at the age of 11 years (z-score = 2.26; P = .023), but not at the age of 7 years (z-score = 1.89; P = .062). This suggests that ToM's superior capacity acquires greater expression and maturity towards late childhood, just before transition to adolescence stage.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

PARAGON II - A single arm multicentre phase II study of neoadjuvant therapy using irinotecan bead in patients with resectable liver metastases from colorectal cancer

PURPOSE

Perioperative chemotherapy confers a 3-year progression free survival advantage following resection of colorectal liver metastases (CRLM), but is associated with significant toxicity. Chemoembolisation using drug eluting PVA microspheres loaded with irinotecan (DEBIRI) allows sustained delivery of drug directly to tumour, maximising response whilst minimising systemic exposure. This phase II single arm study examined the safety and feasibility of DEBIRI before resection of CRLM.

METHODS

Patients with resectable CRLM received lobar DEBIRI 1 month prior to surgery, with a radiological endpoint of near stasis. The trial had a primary end-point of tumour resectability (R0 resection). Secondary end-points included safety, pathologic tumour response and overall survival.

RESULTS

40 patients received DEBIRI, with a median dose of 103 mg irinotecan (range 64-175 mg). Morbidity was low (2.5%, CTCAE grade 2) with no evidence of systemic chemotoxicity. All patients proceeded to surgery, with 38 undergoing resection (95%, R0 resection rate 74%). 30-day post-operative mortality was 5% (n = 2), with neither death TACE related. 66 lesions were resected, with histologic major or complete pathologic response seen in 77.3% of targeted lesions. At median follow up of 40.6 months, 12 patients (34.3%) had died of recurrent disease with a median overall survival of 50.9 months. Nominal 1, 3 and 5-year OS was 93, 78 & 49% respectively.

CONCLUSIONS

Resection after neoadjuvant DEBIRI for CRLM is feasible and safe. Single treatment with DEBIRI resulted in tumour pathologic response and median overall survival comparable to that seen after systemic neoadjuvant chemotherapy. Registered at clinicaltrials.gov (NCT00844233).

Expert opinion on advanced techniques for hemostasis in liver surgery

BACKGROUND

Reduction of perioperative blood loss and intraoperative transfusion are two major factors associated with improving outcomes in liver surgery. There is currently no consensus as to the best technique to achieve this.

METHODS

An international Panel of Experts (EP), made up of hepatobiliary surgeons from well-known high-volume centres was assembled to share their experience with regard to the management of blood loss during liver resection surgery. The process included: a review of the current literature by the panel, a face-to-face meeting and an on-line survey completed by the EP prior to and following the face-to-face meeting, based on predetermined case scenarios. During the meeting the most frequently researched surgical techniques were appraised by the EP in terms of intraoperative blood loss.

RESULTS

All EP members agreed that high quality research on the subject was lacking. Following an agreed risk stratification algorithm, the EP concurred with the existing research that a haemostatic device should always be used along with any user preferred surgical instrumentation in both open and laparoscopic liver resection procedures, independently from stratification of bleeding risk. The combined use of Ultrasonic Dissector (UD) and saline-coupled bipolar sealing device (Aquamantys(®)) was the EP preferred technique for both open and laparoscopic surgery.

CONCLUSIONS

This EP propose the use of a bipolar sealer and UD for the best resection technique and essential equipment to minimise blood loss during liver surgery, stratified according to transfusion risk, in both open and laparoscopic liver resection.

Is radical surgery feasible in liver hydatid cysts in contact with the inferior vena cava?

BACKGROUND

Cysts in contact with the inferior vena cava (IVC) represent a challenge for hepato-pancreatico-biliary surgeons. Although the literature on the topic is scarce, the most widely accepted approach is conservative surgery. Partial cyst resection is recommended, because radical resection is considered a high-risk procedure.

STUDY DESIGN

This was a retrospective study over the period January 2007-December 2012. We operated on 103 patients with liver hydatidosis. A total of 32 patients (31 %) had a liver cyst in contact with the IVC. We proposed a cyst classification based on location of the cyst and length of contact and degrees of involvement of the IVC.

RESULTS

Median size of the contacting cyst measured by computed tomography (CT) was 12 cm. On CT, median length of contact with the IVC was 37 mm. The median degree of involvement was 90°. Radical surgery was performed in 20 patients (62.5 %). No IVC resection was done. Morbidity rate was 28 %, and mortality was 3 %. In follow-up (median 27 months), no relapses or problems related to IVC flow were detected. Postoperative stay and transfusion rate were higher in the conservative surgery group, but these patients presented fewer complications. There was no relationship between circumferential grades and length of contact with the IVC and the type of surgery performed.

CONCLUSIONS

Liver hydatid cysts in contact with the IVC are large cysts usually located in the right liver. They do not normally cause clinical symptoms related to IVC contact. Radical surgery is feasible, and was performed in 60 % of our series, but it is technically demanding. We propose a classification of cysts in contact with the IVC.

Randomized clinical trial of pancreaticogastrostomy versus pancreaticojejunostomy on the rate and severity of pancreatic fistula after pancreaticoduodenectomy

BACKGROUND

Anastomotic leakage of pancreaticojejunostomy (PJ) remains the single most important source of morbidity after pancreaticoduodenectomy (PD). The primary aim of this randomized clinical trial comparing PG with PJ after PD was to test the hypothesis that invaginated PG would result in a lower rate and severity of pancreatic fistula.

METHODS

Patients undergoing PD were randomized to receive either a duct-to-duct PJ or a double-layer invaginated PG. The primary endpoint was the rate of pancreatic fistula, using the definition of the International Study Group on Pancreatic Fistula. Secondary endpoints were the evaluation of severe abdominal complications (Clavien-Dindo grade IIIa or above), endocrine and exocrine function.

RESULTS

Of 123 patients randomized, 58 underwent PJ and 65 had PG. The incidence of pancreatic fistula was significantly higher following PJ than for PG (20 of 58 versus 10 of 65 respectively; P = 0.014), as was the severity of pancreatic fistula (grade A: 2 versus 5 per cent; grade B-C: 33 versus 11 per cent; P = 0.006). The hospital readmission rate for complications was significantly lower after PG (6 versus 24 per cent; P = 0.005), weight loss was lower (P = 0.025) and exocrine function better (P = 0.022).

CONCLUSION

The rate and severity of pancreatic fistula was significantly lower with this PG technique compared with that following PJ.

REGISTRATION NUMBER

ISRCTN58328599 (http://www.controlled-trials.com).

[Outcome at two years corrected age of a cohort of very low birth weight infants from hospitals within the neonatal SEN1500 network]

OBJECTIVE

To describe growth and neurodevelopmental status of 4,944 children who completed a follow-up at two years of corrected age out of the 10,456 newborns with weight ≤1500g born between the years 2002-2007 and discharged from hospitals within the network SEN1500. A total of 522 newborns were excluded as they had some type of malformation. The total number of children assessed represents the 49.76% of children discharged alive and without malformations.

METHODS

A retrospective review was conducted using prospectively collected data in the SEN1500 database. We compared growth data at two years of corrected age according to birth weight and sex. Motor impairment, incidence of cerebral palsy, visual and hearing disabilities, and abnormal neurodevelopment for gestational age were analysed between groups. We studied the associations between cerebral palsy (CP) and perinatal factors.

RESULTS

At 2 years of age 44.2% of children had a weight <2 SD for corrected age. Children with birth weight ≤1000g showed worse outcomes in growth. Some type of motor impairment was observed in 6.96% of the infants, and 4.56% of them were diagnosed with CP. The incidence was higher among males with birth weight ≤1000g. There was an incidence of 5.21% of visual disability, with 0.5% of children being blind in one or both eyes. Cerebral palsy was associated with retinopathy of prematurity, severe intraventricular haemorrhage, and periventricular leukomalacia, in particular cystic periventricular leukomalacia.

Preoperative treatment with bevacizumab in combination with chemotherapy in patients with unresectable metastatic colorectal carcinoma

PURPOSE

This prospective observational study assessed the efficacy of bevacizumab in combination with chemotherapy as preoperative treatment to downsize tumours for radical resection in patients with unresectable metastatic colorectal cancer (mCRC).

PATIENTS/METHODS

Patients with mCRC initially unresectable according to predefined criteria were included. Preoperative treatment consisted of bevacizumab (5 mg/kg) combined with oxaliplatin- or irinotecan-based chemotherapy, which was followed by surgery in patients showing clinical benefit. Resection rate was the primary endpoint. Response rate (RR) and clinical benefit of preoperative chemotherapy, and overall survival (OS) were secondary endpoints.

RESULTS

A total of 120 eligible patients were included and received preoperative treatment. Chemotherapy was irinotecan-based in 73 (61 %) patients, oxaliplatin-based in 25 (21 %) and 22 (18 %) patients received more than one line. A RR of 30 % and a clinical benefit rate of 73 % were observed with preoperative chemotherapy. Metastatic resection was possible in 61 (51 %) patients. Median OS was 33 months (95 % CI 31-NA months) for patients undergoing surgery, and 15 months (95 % CI 11-25 months) in non-operated patients. Thirty-five patients experienced 59 postoperative complications (morbidity rate 57 %).

CONCLUSION

Preoperative bevacizumab-based chemotherapy offers a high surgical rescue rate in patients with initially unresectable mCRC.

Cysto-biliary communication in liver hydatidosis

BACKGROUND

Liver hydatidosis is a severe health problem in endemic areas. Due to migration from these countries to other zones, now it is a worldwide problem. Liver hydatidosis can provoke many complications (abscess, fistula to adjacent organs, migration, etc.), but the most frequent and one of the most severe complication is the communication between the cyst and the biliary tree.

AIM

The aim of this study is to perform a review on the epidemiology, clinical features, diagnostic methods, and therapeutic options to treat the communication between the cyst and the biliary tree.

RESULTS

Due to the lack of randomized clinical trial or meta-analysis on this topic, we performed a classical review and included our personal algorithm.

CONCLUSIONS

The communication between the cyst and the biliary tree varies from a small communication to a frank intrabiliary rupture. The percentage of patients with the communication between the cyst and the biliary tree is not well known because there is no accepted definition. The therapeutic options are multiple and related to the size of the communication, the location of the cyst, and the experience of the hepatobiliary surgeon. ERCP is now an important tool for the treatment of the communication between the cyst and the biliary tree.

Complex liver resection for hepatic tumours involving the inferior vena cava

BACKGROUND

Resection of liver tumours with involvement of inferior vena cava (IVC) is considered to have a high surgical risk.

AIM

We retrospectively reviewed 23 patients who underwent hepatectomy with IVC resection in two West-European liver surgery Units.

METHODS

The tumours included liver metastases (n = 13), hepatocellular carcinoma (n = 4), intrahepatic cholangiocarcinoma (n = 3), liver haemangioma (n = 1), primary hepatic lymphoma (n = 1) and recurrent right adrenal gland carcinoma (n = 1).

RESULTS

IVC resection was associated with right hepatectomy in 8 cases, extended right hepatectomy in 9 cases, extended left hepatectomy in 3 cases, minor liver resection in 2 cases, and right hepatectomy with nephrectomy in one case. In 16 patients the IVC wall involvement was <30% of its circumference, and a tangential vena cava resection was performed. In 7 patients (30%) with >50% involvement, a caval segment was resected and replaced with a 20 mm ringed polytetrafluoroethylene graft. R0-resection was achieved in all patients. Median intraoperative blood loss was 1.100 ml (range 490-15,000). Fourteen patients were transfused with a median of 3 PRC units per patient (range 1-25). Major complications occurred in 9 patients. Postoperative stay in ICU was 2.3 ± 3.4 days (range 1-14) and hospital stay was 17.3 ± 2.6 days (range 5-62). In 14 patients, final pathology demonstrated microscopic IVC infiltration.

CONCLUSIONS

In selected patients with malignant involvement of the liver and IVC, surgical resection en bloc with IVC is the only possibility to achieve R0 resection, with acceptable mortality and morbidity, in units specialized in liver surgery.

PLIO: a generic tool for real-time operational predictive optimal control of water networks

This paper presents a generic tool, named PLIO, that allows to implement the real-time operational control of water networks. Control strategies are generated using predictive optimal control techniques. This tool allows the flow management in a large water supply and distribution system including reservoirs, open-flow channels for water transport, water treatment plants, pressurized water pipe networks, tanks, flow/pressure control elements and a telemetry/telecontrol system. Predictive optimal control is used to generate flow control strategies from the sources to the consumer areas to meet future demands with appropriate pressure levels, optimizing operational goals such as network safety volumes and flow control stability. PLIO allows to build the network model graphically and then to automatically generate the model equations used by the predictive optimal controller. Additionally, PLIO can work off-line (in simulation) and on-line (in real-time mode). The case study of Santiago-Chile is presented to exemplify the control results obtained using PLIO off-line (in simulation).

Customized birthweight standards for a Spanish population

OBJECTIVE

To analyse the biological factors affecting birthweight and to derive customized birthweight standards for a Spanish population.

METHODS

A retrospective cohort was created with all the singleton pregnancies delivered at term and free of pathology in our Institution. Birthweight was modeled by multiple linear regression from maternal (ethnic origin, maternal height, booking weight, smoking, and parity), and fetal (gender, gestational age) characteristics.

RESULTS

In addition to gestational age and sex, height, booking weight, ethnic origin, parity, and smoking all have significant and independent effects on birthweight. Women from East-Asia, Morocco and South-America had newborns on average 83 g, 74 g and 95 g heavier than White-European Spanish women. The effect of smoking was found to be dose-related.

CONCLUSION

We found the relative effect of the maternal and fetal characteristics to be very similar to that reported in previous studies. We report coefficients for ethnic groups that account for a sizeable proportion of the population composition of several European countries.

Platelet deposition in remote cardiac regions after coronary occlusion

BACKGROUND

Activated platelets might contribute to endothelial dysfunction in non-ischaemic territories during acute myocardial infarction. We assessed platelet deposition, coronary flow reserve and contractile function in remote cardiac regions after transient coronary occlusion and their association with systemic platelet activation.

MATERIALS AND METHODS

In 10 pigs (series A) subjected to 48-min occlusion of the left anterior descending coronary artery (LAD), 99mTc-platelet content in the right coronary artery (RCA) and its dependent myocardium was counted after reflow. In 10 pigs (series B) receiving the same occlusion of the RCA, the hyperaemic response at the LAD and systolic shortening in LAD-dependent myocardium were monitored after reperfusion. P-selectin expression on circulating platelets was assessed in both series by flow cytometry.

RESULTS

In series A, platelet counts in the RCA and non-ischaemic myocardium were correlated with platelet content, polymorphonuclear leukocyte infiltration and infarct size in the reperfused zone, as well as with the percentage of P-selectin-positive platelets after reflow. In series B, a transient reduction in peak hyperaemic response in the LAD and sustained contractile dysfunction in non-ischemic myocardium were observed after releasing the RCA occlusion, these changes being also correlated with platelet activation status.

CONCLUSIONS

Ischaemic injury triggers macro- and microvascular platelet deposition and causes an impairment in coronary flow reserve and contractile function in distant regions of the heart, which are related to activation of circulating platelets.

Surgical treatment of liver metastases from colorectal carcinoma in elderly patients. When is it worthwhile?

BACKGROUND

The elderly are under-represented in series of patients operated on for colorectal liver metastases (LM).

OBJECTIVE

To analyse the influence of age on surgery of colorectal LM, and the identification of factors that could be used as exclusion criteria.

PATIENTS AND METHODS

Six hundred and forty-eight patients underwent liver resection between 1990 and 2006. Demographic data, primary tumour related variables, stage of the disease, morbidity, mortality, survival and recurrence were prospectively recorded.

RESULTS

One hundred and sixty of 648 patients (25%) were 70 years old or older. Postoperative mortality was significantly higher in elderly patients (8% vs. 3%, p=0.008). Morbidity was also higher (41% vs. 34%, p=0.008). Survival rate at 1, 3 and 5 years was 88%, 62% and 45% respectively in patients younger than 70 years, and 82%, 48% and 36% in the elderly (p=0.007). Excluding the postoperative mortality, the figures were 90%, 64% and 46%. 90%, 53% and 38% (p=0.061). Disease-free survival rates at 1, 3 and 5 years excluding postoperative mortality were 68%, 32% and 25% in younger patients, compared to 68%, 34% and 30% (p=0.71) in the elderly. Major liver resections increased mortality in the elderly. In the multivariate analyses only a tumour size equal to or more than 10 cm significantly increased the postoperative mortality risk in elderly patients.

CONCLUSIONS

The elderly have a higher mortality. In recent years that difference has been markedly reduced. Excluding the postoperative mortality, the overall survival and disease-free survival are similar between both groups. The criteria to indicate surgery must be the same in both groups.

Effect of subcentimeter nonpositive resection margin on hepatic recurrence in patients undergoing hepatectomy for colorectal liver metastases. Evidences from 663 liver resections

OBJECTIVE

To elucidate if a nonpositive <1-cm resection margin has any effect on hepatic recurrence in patients undergoing liver resection for colorectal liver metastases.

PATIENTS AND METHODS

Six hundred and nine patients underwent 663 liver resections. Patients with positive margin were excluded from the analysis. Two groups were studied: group A, <1-cm resection margin and group B, > or =1-cm resection margin.

RESULTS

A total of 545 liver resections in 523 patients were carried out with nonpositive resection margins. With a median follow-up of 25 months, the 5-year cumulative hepatic recurrence reached 54% in group A (n = 206) and 41% in group B (n = 339). Factors associated with hepatic recurrence were synchronic metastases (P = 0.0015), bilobar (P < 0.001), two or more metastases (P < 0.001), margin <1 cm (P = 0.0123) and extrahepatic disease (P = 0.0037). A strong correlation between resection margin and number of metastases was confirmed (P < 0.001). At multivariate analysis only two factors were independent predictors of hepatic recurrence: multinodular disease in the liver specimen [> or =4 metastases hazard ratio (HR) = 3.45; 95% confidence interval (CI): 2.2-5.38; P < 0.001] and extrahepatic disease at hepatectomy (HR = 1.58; 95% CI: 1.58-3.32).

CONCLUSION

Subcentimeter nonpositive resection margins do not directly influence hepatic recurrence in patients undergoing hepatectomy for colorectal liver metastases.

[Radiofrequency ablation of hepatic tumors]

This article aims to review the state of the art in ablation techniques for hepatic lesions. In addition to discussing the indications, outcomes, and potential complications of the technique, we illustrate the spectrum of imaging findings after treatment. Recent years have seen the development of a wide variety of minimally invasive techniques to treat liver cancer. These include ethanol injection, and thermal ablation using radiofrequency, laser, microwaves, or cryosurgery. Percutaneous radiofrequency ablation is one of the most promising non-surgical treatments for hepatic neoplasms. The results of several studies show that radiofrequency ablation enables adequate local control of tumors with few complications, achieving acceptable survival rates. Radiofrequency ablation can be performed using any imaging technique, although it is most commonly performed under ultrasound guidance. CT and MRI show the degree of tumor necrosis better and are more frequently employed in follow up. This article reviews the indications and contraindications for the procedure, potential complications, long-term outcome, and imaging findings for percutaneous radiofrequency ablation of hepatic tumors.

TP53 status is an important prognostic marker for patients with hepatic metastases from colorectal carcinoma

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Background: The aim of this study was to analyze the value of TP53 gene mutations as a prognostic marker to improve the selection of patients candidates to surgery in a consecutive series of liver metastases from colorectal cancer patients. Methods: 91 patients with liver metastases from colorectal carcinoma (CRC) were included. Mutational study of TP53 gene, exons 4 to 10, was assessed both in paraffin-embedded hepatic metastasis and normal liver parenchyma by SSCP (Single Strand Chain Polymorphism) followed by sequencing of abnormal electrophoretic mobility patterns. Immunostaining of P53 and P21 proteins were assessed in the same group of patients. Results: Forty-eight out 91 (50.05%) metastases showed mutation in TP53. Higher incidence of mutations was detected in exons 5–8, although exons 9 and 10 were mutated in 28.26% of metastases. Protein-truncating mutations (nonsense and frameshift) occur in 47.8% of metastasis harboring TP53 mutations. TP53 mutation was associated with poor prognosis in univariate (P=0.0062) and multivariate Cox proportional hazard model (P=0.012) analysis. Prognosis association was maintained in the group of patients undergoing radical resection, named R0 series (n=79; P=0.008). High prevalence of TP53 mutations happen in patients with >3 metastases (65.6%; P=0.034), primary tumors Duke’s C-D stages (57.4%; 63.0%; respectively; p=0.026) and patients with age <57 years at resection. Interestingly, patients with TP53 mutations in their metastases relapsed earlier after the resection of the primary tumor (P=0.026). Postoperative 5-FU-based chemotherapy showed a better survival outcome in patients with wild-type TP53 hepatic metastases (HR: 2.92; 95% CI: 1.32–6.46; P=0.006). Conclusions: TP53 mutational status seems to be an important prognostic factor in patients with hepatic metastases from CRC.

No significant financial relationships to disclose.

LiverMetSurvey: Analysis of clinicopathologic factors associated with the efficacy of preoperative chemotherapy in 2,122 patients with colorectal liver metastases

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Background: LiverMetSurvey is an international, internet-based registry designed to assess the efficacy of multimodality treatment options for colorectal liver metastases (CLM) by analyzing outcomes following hepatic resection (HR) in a large number of patients. Methods: Data were analyzed for the 2,122 patients entered into LiverMetSurvey by six hepatobiliary centers from inception to August 2004 (HR: 1974 to 2004; 1,306 men: 816 women; mean age: 61 years). The distributions of potential prognostic factors including age, sex, primary tumor site, timing of metastasis diagnosis, tumor number, diameter of the largest metastasis, bilaterality, and treatment with chemotherapy were compared to survivals using univariate and multivariate statistics. Results: Metastases originated in the colon in 69% of patients and were synchronous (diagnosed within 3 mo of primary tumor treatment) in 49% of patients. 34% of patients had ≥ 3 metastases and tumors were distributed bilaterally in 43% of cases. The mean size of the largest metastasis was 41.8 mm. 55% of patients were treated with preoperative systemic chemotherapy. Following resection, 60-day mortality was 1.2% and median, 5-year, and 10-year overall survivals (OS) were 46 mo, 42%, and 26%, respectively. Variables independently associated with poor prognosis included number of metastases > 3 (p<0.0001), bilateral metastases (p=0.0002), and size of the largest metastasis > 5 cm (p=0.03). Preoperative chemotherapy (PC) did not appear to benefit patients with solitary CLM (5-yr OS: PC 45% vs. no PC 58%), but was associated with improved survival in patients with > 5 metastases (5-yr OS: PC 22% vs. no PC 12%). Conclusions: Assessment of outcomes for the first 2,122 registrants to LiverMetSurvey not only confirms the prognostic importance of intrahepatic tumor burden, but also indicates that the ability of preoperative systemic chemotherapy to improve survivals is limited to patients with multiple (> 5) metastases. In addition, this analysis demonstrates the potential for LiverMetSurvey, which is now prospectively enrolling patients from over 40 centers, to determine the therapeutic value of current and future treatment strategies.

No significant financial relationships to disclose.

Severe hypernatremic dehydration secondary to undetected lactation failure: usefulness of sodium levels in breast milk

There is a concern that lactation failure and neonatal morbidity might be more common than previously thought. Maybe the early discharge, the lack of timely follow-up, or poor information during pregnancy or after delivery play important roles. A case of severe hypernatremic dehydration secondary to lactation failure is reported and we analyze recent recommendations.

Clinical and virological effects during two years of ongoing adefovir dipivoxil in the treatment of lamivudine-resistant chronic hepatitis B infection

OBJECTIVE

Our aim was to evaluate the efficacy and safety of adding adefovir to lamivudine therapy for hepatitis B virus (HBV)-infected patients resistant to Ramivudine.

PATIENTS AND METHODS

Among 17 studied patients, 7 had chronic active HBV infection and 10 were posttransplant with HBV infection (9 with de novo HBV). They received lamivudine plus adefovir therapy for 2 years. We assessed reductions in serum HBV-DNA and alanine aminotransferase (ALT) levels, loss of HBeAg (in HBeAg+ cases), and HBsAg clearance.

RESULTS

A virological response, as defined by HBV-DNA below the cut off by hybridization, was observed in 12 (70.6%) patients and loss of HBeAg in 4 (44.4%) of the 9 initially HBeAg-positive cases. A biochemical response, defined as a decreased serum ALT to the normal range, occurred in 4 (26.7%) patients. Median serum creatinine increased in 3 of 15 (20%) patients, excluding those on hemodialysis. There were two noteworthy cases of sustained HBsAg seroconversion with adefovir (11.8%): one patient with de novo HBV infection posttransplantation and positive hepatitis C virus-RNA serology, and one patient with decompensated HBV cirrhosis in whom viral replication ceased, making him eligible for transplantation.

CONCLUSIONS

Currently, adefovir is an effective rescue therapy that broadens the existing range of options for patients with lamivudine-resistant chronic hepatitis B infection, particularly those with decompensated cirrhosis awaiting a liver graft, and those with recurrent posttransplantation HBV. The relatively small biochemical response seen in these patients may be attributable to the high prevalence of concomitant hepatitis C virus infection (41%).

Resultados iniciales del Registro Nacional de Cirugía Hepática por Laparoscopia

INTRODUCTION

Experience in laparoscopic liver surgery is limited, and multicenter studies with large series are required for a critical evaluation of this type of surgery.

OBJECTIVE

To analyze the results of the National Registry of Laparoscopic Liver Surgery. Indications, technical features, conversion rates, morbidity, and mortality were analyzed.

PATIENTS AND METHOD

Seventy-four patients from 10 centers who underwent surgery between February 2000 and April 2005 were included. There were 58 women and 16 men, with a mean age of 55 years. More than one lesion was present in 16 patients. Consequently, 74 patients with 156 lesions were treated.

RESULTS

Forty-six patients had cystic lesions (26 simple cysts, 13 polycystic disease, five hydatid cysts and two cystic adenomas). Surgical treatment consisted of 37 fenestrations, five cystopericystectomies, two atypical resections, one segmentectomy and one bisegmentectomy of segments II-III. In 28 patients the lesions were solid (four adenomas, six focal nodular hyperplasias, three hemangiomas, four hepatocarcinomas, five colorectal metastases, two lung metastases, one breast metastasis, one malignant melanoma metastasis, one pancreatic vipoma metastasis, and one lymphoma). Ten bisegmentectomies of segments II-III, 17 atypical resections and one segmentectomy of segment III were performed. Other surgery was associated in 23 patients. The mean operating time was 160.5 minutes and the conversion rate was 8%. The mean length of hospital stay was 5.6 days and was less than 5 days in 78% of the patients. Analgesia was administered for less than 48 hours in 55%. Morbidity was observed in eight patients (10.8%). Reoperations were performed in three patients. There was no mortality in this series.

CONCLUSIONS

Laparoscopic hepatic resection is safe and feasible in selected patients. Large, controlled series are required to determine long-term outcomes. The national registry provides a good basis for evaluating laparoscopic liver surgery in Spain.