Review: Towards the next-generation models of the rumen microbiome for enhancing predictive power and guiding sustainable production strategies

The rumen ecosystem harbours a galaxy of microbes working in syntrophy to carry out a metabolic cascade of hydrolytic and fermentative reactions. This fermentation process allows ruminants to harvest nutrients from a wide range of feedstuff otherwise inaccessible to the host. The interconnection between the ruminant and its rumen microbiota shapes key animal phenotypes such as feed efficiency and methane emissions and suggests the potential of reducing methane emissions and enhancing feed conversion into animal products by manipulating the rumen microbiota. Whilst significant technological progress in omics techniques has increased our knowledge of the rumen microbiota and its genome (microbiome), translating omics knowledge into effective microbial manipulation strategies remains a great challenge. This challenge can be addressed by modelling approaches integrating causality principles and thus going beyond current correlation-based approaches applied to analyse rumen microbial genomic data. However, existing rumen models are not yet adapted to capitalise on microbial genomic information. This gap between the rumen microbiota available omics data and the way microbial metabolism is represented in the existing rumen models needs to be filled to enhance rumen understanding and produce better predictive models with capabilities for guiding nutritional strategies. To fill this gap, the integration of computational biology tools and mathematical modelling frameworks is needed to translate the information of the metabolic potential of the rumen microbes (inferred from their genomes) into a mathematical object. In this paper, we aim to discuss the potential use of two modelling approaches for the integration of microbial genomic information into dynamic models. The first modelling approach explores the theory of state observers to integrate microbial time series data into rumen fermentation models. The second approach is based on the genome-scale network reconstructions of rumen microbes. For a given microorganism, the network reconstruction produces a stoichiometry matrix of the metabolism. This matrix is the core of the so-called genome-scale metabolic models which can be exploited by a plethora of methods comprised within the constraint-based reconstruction and analysis approaches. We will discuss how these methods can be used to produce the next-generation models of the rumen microbiome.

Comparative prognostic value of parameters of right ventricular pulsatile afterload in patients with advanced heart failure awaiting heart transplantation

Background

Right ventricular (RV) function demonstrated a strong impact on survival of patients with advanced heart failure with reduced ejection fraction (HFrEF). In particular, increased RV pulsatile afterload (RVPA) was associated with poor prognosis. Several right heart catheterization-derived parameters have been proposed to characterize RVPA, including pulmonary artery compliance (PAC), elastance (PAE) and pulsatile index (PAPi). However, among these indices, the best prognostic indicator is undetermined.

Purpose

To assess the prognostic relevance of RVPA parameters in patients with advanced HFrEF evaluated for heart transplantation.

Methods

149 patients with end-stage HFrEF underwent right heart catheterization during the evaluation for heart transplantation. All patients were clinically followed up until death or any censoring events including heart transplantation, left ventricular assist device (LVAD) and hospitalization for acute heart failure. Cox regression and ROC-curve analysis were used to test the prognostic value of RVPA determinants. Multivariate regression models with C-statistics were used to test the independent predictive value of RVPA indices.

Results

The mean age of the study population was 56.6±10.1 years and 85.2% were male. The most frequent aetiology of HFrEF was ischemic cardiomyopathy (52.3%). Mean LV ejection fraction was 25.7±10.2%.

During a mean follow up time of 17±15 months, 29 (19.5%) patients met the primary endpoint: 9 (6%) patients died, 4 (2.68%) patients underwent an urgent heart transplantation, 11 (7.3%) patients underwent urgent LVAD implantation (as bridge to transplantation therapy) and 5 (3.3%) were hospitalized for HF.

Patients who met the primary endpoint were significantly older patients (61.2±7.8 vs 55.4±10.2, p=0.006) and with worse hemodynamic profile than event-free survivors (PAC [1.8±0.8 vs. 2.7±2.0, p=0.01], mPAP [33.5±11.3 vs. 29.3±11.0, p=0.05], PVR [3.0±1.6 vs. 2.6±2.0, p=0.09] and PAE [1.12±0.5 vs. 0.98±0.6, p=0.04]).

Among the RVPA parameters PAC<1.9 mL/mmHg (HR 4.0, CI 1.3–6.0, p=0.007) and PAE>0.9 mmHg/mL (HR 2.5, 95% CI 1.1–5.2, p=0.02) were associated with the primary endpoint. On the contrary, PAPi was not significantly associated with the outcome.

PAC demonstrated a superior predictive value for the composite adverse outcome compared with pulmonary vascular resistances (PVR) (AUC comparison p=0.019) and PAPi (p=0.03) but similar compared with PAE (p=0.19) and mPAP (p=0.51). In multivariable regression models, PAC, but not PAE showed incremental prognostic value compared with cardiac index (p=0.02).

Conclusions

Hemodynamic indices of RVPA are associated with worse survival in patients with end-stage heart failure. In particular, PAC and PAE demonstrated superior prognostic value compared with PAPi and steady-state PVR. Moreover, PAC showed incremental prognostic value compared with cardiac index in patients awaiting heart transplantation.

Funding Acknowledgement

Type of funding sources: None.

A method for bivalve shells characterization by FT-IR Photoacoustic Spectroscopy as a tool for environmental studies

Fourier Transform Infrared Spectroscopy has been employed to investigate the composition of the shells of two marine bivalves Mytilus galloprovincialis and Corbula gibba from four samples collected from the Mar Piccolo of Taranto (Ionian Sea, Southern Italy). Bivalve shells are composed of 95–99.9% calcium carbonate (CaCO₃), while the remaining portion is constituted by organic matrix, which in some cases may incorporate pollutants from the surrounding environment. Recognizing the role of bivalves in the carbon biogeochemical cycle and their economic importance for aquaculture, we aimed to develop a methodology for shells powder samples preparation and analysis. The main objective of the study was to demonstrate the feasibility of Fourier Transform Infrared photoacoustic spectroscopy to perform a fast sample analysis in order to detect the possible presence of pollutants in the shells.

The results revealed an unbiased differentiation between the shell compositions of the two bivalve selected species. Moreover, the spectra interpretation indicated that C. gibba specimens recorded a shell matrix contaminated by organic pollutants present in the surrounding environment. In conclusion, the described methodology including sample preparation tailored for photoacoustical investigations demonstrated to be a tool for the characterization of bivalve shells contamination enhancing environmental studies of polluted marine areas.•

Bivalve species were collected from sampling stations located in the Mar Piccolo of Taranto (Ionian Sea, Southern Italy).

•

Samples preparation stages include: sonication, grinding and fractioning by sieving.

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FT-IR PAS spectral region of interest is in the mid-infrared between 4000 and 400 cm⁻¹.

The transCampus Metabolic Training Programme Explores the Link of SARS-CoV-2 Virus to Metabolic Disease

Currently, we are experiencing a true pandemic of a communicable disease by the virus SARS-CoV-2 holding the whole world firmly in its grasp. Amazingly and unfortunately, this virus uses a metabolic and endocrine pathway via ACE2 to enter our cells causing damage and disease. Our international research training programme funded by the German Research Foundation has a clear mission to train the best students wherever they may come from to learn to tackle the enormous challenges of diabetes and its complications for our society. A modern training programme in diabetes and metabolism does not only involve a thorough understanding of classical physiology, biology and clinical diabetology but has to bring together an interdisciplinary team. With the arrival of the coronavirus pandemic, this prestigious and unique metabolic training programme is facing new challenges but also new opportunities. The consortium of the training programme has recognized early on the need for a guidance and for practical recommendations to cope with the COVID-19 pandemic for the community of patients with metabolic disease, obesity and diabetes. This involves the optimal management from surgical obesity programmes to medications and insulin replacement. We also established a global registry analyzing the dimension and role of metabolic disease including new onset diabetes potentially triggered by the virus. We have involved experts of infectious disease and virology to our faculty with this metabolic training programme to offer the full breadth and scope of expertise needed to meet these scientific challenges. We have all learned that this pandemic does not respect or heed any national borders and that we have to work together as a global community. We believe that this transCampus metabolic training programme provides a prime example how an international team of established experts in the field of metabolism can work together with students from all over the world to address a new pandemic.

Activities and vectors responsible for the biological pollution in the Taranto Seas (Mediterranean Sea, southern Italy): a review

Biological pollution, caused by the negative impact of alien species, also known as non-indigenous species (NIS), is regarded as one of the greatest threat to marine ecosystems. The recent upsurge in the number and spread of these species drew attention to putative vectors such as shipping and shellfish importation for culture and consumption. The port of Taranto in Southern Italy is a hub for several vectors as it serves commercial and military shipping, fishing and recreational boating, in addition to shellfish importation. An analysis of anthropogenic activities and possible vectors in Taranto Seas was recently carried out within the framework of the RITMARE Project, involving local stakeholders. Different categories of stakeholders answered dedicated questionnaires with a high degree of reticence, and this highlighted a general lack of awareness of the problems associated with alien species. Consequently, there is a strong need to instil a truly ecological awareness among the general public and stakeholders.

Microbenthic community structure and trophic status of sediments in the Mar Piccolo of Taranto (Mediterranean, Ionian Sea)

This study aimed to assess the benthic ecosystem trophic status in a heavily polluted marine area and the response of the microbenthic community to multiple and diffuse anthropogenic impacts, integrating information coming from the active and resting (plankton's cysts) components of microbenthos. Two sampling campaigns were carried out in the period 2013-2014 and four sampling sites at different levels of industrial contamination were chosen within the first and second inlet of the Mar Piccolo of Taranto. The chemical contamination affected to a higher extent the active microbenthos than the resting one. In the central part of the first inlet, characterised by more marine features, thrives a very rich and biodiverse microbenthic community. In contrast, at the polluted site near the military navy arsenal, extremely low densities (9576 ± 1732 cells cm(-3)) were observed for active microbenthos, but not for the resting community. Here, the high level of contamination selected for tychopelagic diatom species, i.e., thriving just above the surface sediments, while the other life forms died or moved away. Following the adoption of a 10 μm mesh, for the first time, resting spores produced by small diatoms of the genus Chaetoceros were found. Our results further indicate that although the Mar Piccolo is very shallow, the benthic system is scarcely productive, likely as a consequence of the accumulated contaminants in the surface sediments that probably interfere with the proper functioning of the benthic ecosystem.

Incretins or anti-incretins? A new model for the "entero-pancreatic axis"

The role of incretins in glucose homeostasis is well known. Yet, in recent years, the sustained weight loss and rapid glycemic control following bariatric surgery has challenged our understanding of the intestinal-pancreatic interaction. This in turn led to the introduction of metabolic surgery, an innovative medical discipline in which a surgical manipulation of the gastrointestinal tract (e. g., through a Roux-en-Y gastric bypass, RYGB, or Bilio-Pancreatic-Diversion, BPD) yields a sustained remission of diabetes mellitus. The pathophysiological background of this metabolic effect is, amongst other things, based on the anti-incretin theory. This theory postulates that in addition to the well-known incretin effect, nutrient passage through the GI-tract could also activate negative feedback mechanisms (anti-incretins) to balance the effects of incretins and other postprandial glucose-lowering mechanisms (i. e., suppression of ghrelin, glucagon, and hepatic glucose production via activation of nutrient sensing). This in turn prevents postprandial hyperinsulinemic hypoglycemia. The bypass of the duodenum, the entire jejunum and the first portion of the ileum by BPD induce normalization of peripheral insulin sensitivity, while the bypass of a shorter intestinal tract by RYGB mainly improves the hepatic insulin sensitivity. In addition, RYGB greatly increases insulin secretion. Therefore, metabolic surgery highlights the important role of the small intestine in glucose homeostasis, while until few years ago, it was only the pancreas and the liver that were thought to represent the regulatory organs for glucose disposal.

[Time course of excretion of tebuconazole and its metabolites in vineyard workers]

Tebuconazole (TEB) is a fungicide widely used in vineyards. This work aimed at the identification of urinary metabolites of TEB for the biological monitoring of exposure, and to study their kinetics of excretion. Major urinary metabolites of TEB in rats are t-butyl-hydroxy-and-carboxy-tebuconazole (TEB-OH and TEB-COOH). TEB and these metabolites were determined in urine samples of 5 wine growers who collected each void before (24 hours), during and after (48 hours) TEB application. These chemicals were found in 95%, 100% and 100% of the samples with levels of < 1.5-13.4 microg/L for TEB, 5.2-749 microg/L for TEB-OH e 2.8-234 microg/l for TEB-COOH. TEB-OH is the major metabolite of TEB, its concentration increases at the end of exposure and peaks after 16-24 hours. TEB-COOH has similar pattern. TEB-OH and TEB -COOH are promising candidates for biological monitoring of TEB exposure; preliminary results suggest the day after the application as the best sampling time.

Bariatric surgery: an IDF statement for obese Type 2 diabetes

The International Diabetes Federation Taskforce on Epidemiology and Prevention of Diabetes convened a consensus working group of diabetologists, endocrinologists, surgeons and public health experts to review the appropriate role of surgery and other gastrointestinal interventions in the treatment and prevention of Type 2 diabetes. The specific goals were: to develop practical recommendations for clinicians on patient selection; to identify barriers to surgical access and suggest interventions for health policy changes that ensure equitable access to surgery when indicated; and to identify priorities for research. Bariatric surgery can significantly improve glycaemic control in severely obese patients with Type 2 diabetes. It is an effective, safe and cost-effective therapy for obese Type 2 diabetes. Surgery can be considered an appropriate treatment for people with Type 2 diabetes and obesity not achieving recommended treatment targets with medical therapies, especially in the presence of other major co-morbidities. The procedures must be performed within accepted guidelines and require appropriate multidisciplinary assessment for the procedure, comprehensive patient education and ongoing care, as well as safe and standardized surgical procedures. National guidelines for bariatric surgery need to be developed for people with Type 2 diabetes and a BMI of 35 kg/m² or more.

Does the nasogastric tube has a role in elective colo-rectal surgery?

INTRODUCTION

Routine use of nasogastric tubes (NGT) after abdominal operations is intended to hasten the return of bowel function, diminish the risk of anastomotic leakage and prevent pulmonary complications. The aim of our study was to prospectively assess the tolerability and the safety of the non use of NGT after elective colorectal open operations.

PATIENTS AND METHODS

Between March 2009 and December 2010, 110 consecutive patients underwent colo-rectal elective open surgery for neoplasm without nasogastric decompression. We analyzed the incidence of nausea and vomiting, the pulmonary complications, the return of bowel function the deep wound breakdown (fascial dehiscence) and the anastomotic leakage.

RESULTS

Only 15 patients (13,6%) reported nausea without vomiting immediately after surgery and 9 cases of vomiting were observed (8%), requiring the insertion of the NGT (nasogastric tube) in 5 (4,5%). A total of 105 patients (96,3%) were NGT free. No deep wound dehiscence was observed and only one real pneumonia occurred. Anastomotic dehiscence occurred in 4 patients (3,6%) and a second surgical procedure was needed in three cases. The return of bowel function, except in the last four patients, occurred in 3,8 days average (range 2-7 days).

CONCLUSION

We confirm the uselessness of the NGT in the framework of fast track program adopted in elective open colo-rectal surgery.

Bariatric surgery: an IDF statement for obese Type 2 diabetes

The International Diabetes Federation Taskforce on Epidemiology and Prevention of Diabetes convened a consensus working group of diabetologists, endocrinologists, surgeons and public health experts to review the appropriate role of surgery and other gastrointestinal interventions in the treatment and prevention of Type 2 diabetes. The specific goals were: to develop practical recommendations for clinicians on patient selection; to identify barriers to surgical access and suggest interventions for health policy changes that ensure equitable access to surgery when indicated; and to identify priorities for research. Bariatric surgery can significantly improve glycaemic control in severely obese patients with Type 2 diabetes. It is an effective, safe and cost-effective therapy for obese Type 2 diabetes. Surgery can be considered an appropriate treatment for people with Type 2 diabetes and obesity not achieving recommended treatment targets with medical therapies, especially in the presence of other major co-morbidities. The procedures must be performed within accepted guidelines and require appropriate multidisciplinary assessment for the procedure, comprehensive patient education and ongoing care, as well as safe and standardized surgical procedures. National guidelines for bariatric surgery need to be developed for people with Type 2 diabetes and a BMI of 35 kg/m(2) or more.

Bariatric surgery: an IDF statement for obese Type 2 diabetes

The International Diabetes Federation Taskforce on Epidemiology and Prevention of Diabetes convened a consensus working group of diabetologists, endocrinologists, surgeons and public health experts to review the appropriate role of surgery and other gastrointestinal interventions in the treatment and prevention of Type 2 diabetes. The specific goals were: to develop practical recommendations for clinicians on patient selection; to identify barriers to surgical access and suggest interventions for health policy changes that ensure equitable access to surgery when indicated; and to identify priorities for research. Bariatric surgery can significantly improve glycaemic control in severely obese patients with Type 2 diabetes. It is an effective, safe and cost-effective therapy for obese Type 2 diabetes. Surgery can be considered an appropriate treatment for people with Type 2 diabetes and obesity not achieving recommended treatment targets with medical therapies, especially in the presence of other major co-morbidities. The procedures must be performed within accepted guidelines and require appropriate multidisciplinary assessment for the procedure, comprehensive patient education and ongoing care, as well as safe and standardized surgical procedures. National guidelines for bariatric surgery need to be developed for people with Type 2 diabetes and a BMI of 35 kg/m(2) or more.

The effect of bilio-pancreatic diversion on type 2 diabetes in patients with BMI <35 kg/m2

AIMS/HYPOTHESIS

To aim of the study was to investigate the effect of bilio-pancreatic diversion (BPD) on type 2 diabetes in patients with BMI <35 kg/m(2).

METHODS

OGTTs were performed and anthropometric data were compared between five diabetes patients (BMI 27-33 kg/m(2)) following BPD and seven diabetes patients after a low-energy diet. Insulin secretion was computed by C-peptide deconvolution. A euglycaemic-hyperinsulinaemic clamp was performed only in the BPD group and the M value measured.

RESULTS

One month after BPD, fasting and 2 h post-OGTT glycaemia decreased from 15.22 +/- 3.22 to 6.22 +/- 0.51 mmol/l (p = 0.043), while insulin sensitivity increased significantly. No significant changes were observed in the low-energy diet group. Insulin secretion did not differ significantly after either intervention. Diabetes amelioration (change in HbA(1c) level) was observed up to 18 months after BPD without pharmacological therapy.

CONCLUSIONS/INTERPRETATION

BPD can achieve adequate control of type 2 diabetes also in patients with BMI <35 kg/m(2). The rapid postoperative remission of diabetes is primarily related to an improvement in insulin sensitivity.

Bariatric surgery for metabolic disorders

Help for diabetics

[Feasibility and reliability of the study of sentinel lymph nodes with immunohistochemical technique in colonic carcinoma]

Sentinel lymph node sampling, in patients with resectable colon cancer, improved identification of lymph node disease and identified patients likely to benefit from adjuvant therapy. This study examined whether sentinel node sampling accurately predicted lymph node status for patients with resectable colon cancer.

Obesity surgery: evidence-based guidelines of the European Association for Endoscopic Surgery (EAES)

BACKGROUND

The increasing prevalence of morbid obesity together with the development of laparoscopic approaches has led to a steep rise in the number of bariatric operations. These guidelines intend to define the comparative effectiveness and surrounding circumstances of the various types of obesity surgery.

METHODS

A consensus panel representing the fields of general/endoscopic surgery, nutrition and epidemiology convened to agree on specific questions in obesity surgery. Databases were systematically searched for clinical trial results in order to produce evidence-based recommendations. Following two days of discussion by the experts and a plenary discussion, the final statements were issued.

RECOMMENDATIONS

After the patient's multidisciplinary evaluation, obesity surgery should be considered in adults with a documented BMI greater than or equal to 35 and related comorbidity, or a BMI of at least 40. In addition to standard laboratory testing, chest radiography, electrocardiography, spirometry, and abdominal ultrasonography, the preoperative evaluation of obesity surgery patients also includes upper gastrointestinal endoscopy or radiologic evaluation with a barium meal. Psychiatric consultation and polysomnography can safely be restricted to patients with clinical symptoms on preoperative screening. Adjustable gastric banding (GB), vertical banded gastroplasty (VBG), Roux-en-Y gastric bypass (RYGB) and biliopancreatic diversion (BPD) are all effective in the treatment of morbid obesity, but differ in degree of weight loss and range of complications. The choice of procedure therefore should be tailored to the individual situation. There is evidence that a laparoscopic approach is advantageous for LAGB, VBG, and GB (and probably also for BPD). Antibiotic and antithromboembolic prophylaxis should be used routinely. Patients should be seen 3 to 8 times during the first postoperative year, 1 to 4 times during the second year and once or twice a year thereafter. Outcome assessment after surgery should include weight loss and maintainance, nutritional status, comorbidities and quality-of-life.

[Work, cardiopathy, and sports]

BACKGROUND

Heart disease is the main cause of early disability and premature death in Europe. Regular physical activity may prevent heart disease, diabetes, ictus, and obesity. Nevertheless, a certain resistance to a dynamic lifestyle, lack of free time, lack of motivation and other factors are frequently encountered.

OBJECTIVES

To stress the importance of physical activity in the prevention of cardiovascular disease.

METHODS

A literature review of the main risk factors for cardiovascular disease was carried out.

RESULTS AND CONCLUSION

It has been shown that physical exercise is beneficial to the cardiovascular apparatus and to the bones and joints, by improving some metabolic parameters. Recent studies have shown that a personalized, moderate physical activity should be suggested for primary and secondary prevention, in particular for subjects with coronary artery disease and left ventricular dysfunction. An increase in sports activity and physical exercise at work and at school is recommended so as to improve quality of life and promote home rehabilitation. Some promising experience has already been made among workers and their families with excellent results, as shown by a follow-up period of three years.

Laparoscopic total mesorectal excision (TME) for rectal cancer surgery: long-term outcomes

BACKGROUND

Total mesorectal excision (TME) offers the lowest reported rates of local recurrence and the best survival results in patients with rectal cancer. However, the laparoscopic approach to resection for colorectal cancer remains controversial due to fears that oncologic principles will be compromised. We assessed the feasibility, safety and long-term outcome of laparoscopic rectal cancer resections following the principles of TME. The aim of this study was to evaluate the perioperative outcome and long-term results of laparoscopic TME.

METHODS

We reviewed the prospective database of 102 consecutive unselected patients undergoing laparoscopic TME for rectal cancer between November 1991 and December 2000. Follow-up was done through office charts or direct patient contact. Recurrence and survival curves were generated by the Kaplan-Meier method.

RESULTS

Laparoscopic TME was completed successfully in 99 patients, whereas conversion to an open approach was required in three cases (3%). The overall morbidity and mortality rates were 27% and 2%, respectively, with an overall anastomotic leak rate of 17%. Of the 102 patients, four were excluded from the oncologic evaluation because final pathology was not confirmatory (two had anal canal squamous cell carcinoma and two had villous adenoma with dysplasia). In 90 of the 98 remaining patients (91.8%), the resection was considered curative. The remainder had a palliative resection due to synchronous metastatic disease or locally advanced disease. Mean follow-up was 36 months (range, 6-96). There were no trocar site recurrences. The local recurrence rate was 6%, and the cancer-specific survival of all curatively resected patients was 75% at 5 years. The overall survival rate of all curatively resected patients was 65% at 5 years; mean survival time was 6.23 years (95% confidence interval [CI], 5.39-7.07).

CONCLUSION

Laparoscopic TME is feasible and safe. The laparoscopic approach to the surgical treatment of operable rectal cancer does not seem to entail any oncologic disadvantages.

Endoscopic endocrine neck surgery with carbon dioxide insufflation: the effect on intracranial pressure

Background

The endoscopic approach to the thyroid and parathyroid glands requires insufflation with carbon dioxide at 10–15 mmHg. This may decrease the cerebral venous return and increase intracranial pressure (ICP). The aim of this study was to evaluate the effect of carbon dioxide neck insufflation on ICP and haemodynamic variables.

Methods

Twelve 25-kg pigs underwent endoscopic thyroid dissection using carbon dioxide insufflation at 0 mmHg (sham), 10 mmHg (G10), 15 mmHg (G15) and 20 mmHg (G20). Three pigs were used in each group. ICP, mean arterial pressure, central venous blood pressure (CVP), cardiac output and blood gas were measured at baseline, 30, 60 and 120 min.

Results

There were no differences in mean ICP between the sham group and G10. However, ICP significantly increased in G15 and G20. The partial pressure of carbon dioxide was similar in G10 and G15 (mean(s.d.) 49·8(2·4) and 49·8(5·2) mmHg respectively at 120 min), while it was dramatically increased in G20 (63·1(6·9) mmHg at 120 min). Haemodynamic parameters were stable in all groups except for G20 in which CVP significantly increased with respect to baseline (8·5(2·1) versus 1·3(1·5) mmHg; P &lt; 0·01). Jugular vein collapse occurred during endoscopic dissection at all insufflation pressures, but pigs operated at 10 mmHg were able to maintain an intermittent blood flow.

Conclusion

A severe increase in ICP occurs with insufflation pressures higher than 15 mmHg, possibly owing to decreased cervical venous blood flow. Carbon dioxide insufflation up to 10 mmHg does not alter ICP, and is recommended for clinical application in endoscopic endocrine neck surgery.

Endoscopic approach for carotid artery surgery

BACKGROUND

Although recent advances in the treatment of carotid artery stenosis have included endovascular angioplasty and stent placement, carotid endarterectomy is still the approach of choice for carotid disease and is one of the most commonly performed operations today. Minimally invasive surgeries involving the neck have recently been performed for thyroid and parathyroid diseases. The purpose of this study was to evaluate the feasibility of an endoscopic approach for carotid artery surgery in a large animal model.

METHODS

Eight 25- to 30-kg pigs were used. Animals underwent endoscopic carotid dissection with carbon dioxide insufflation at 10 mmHg. A 1.5- to 2-cm arteriotomy was made in the common carotid artery. Four animals underwent direct arteriotomy closure, and four animals underwent synthetic patch graft placement using intracorporeal suturing techniques. Open examination of the operative site and carotid angiograms were performed at the end of the procedure. Operative time was recorded in the last four cases.

RESULTS

All animals tolerated the procedure well and carotid artery repair was successfully performed in all cases using a four-trocar technique. The entire extent of the cervical common and internal carotid arteries was exposed up to the cranial base. Cranial nerves and cervical structures were clearly visualized and preserved. No bleeding occurred at the end of the procedure. Carotid angiograms confirmed patent, nonstenotic vessels in all cases.

CONCLUSION

Endoscopic approach for carotid surgery is technically feasible in the porcine model. This approach may represent a valuable option for surgery of the carotid artery since it offers the advantages of minimally invasive techniques while maintaining the benefits of surgical arterial repair.

Is the identification of the external branch of the superior laryngeal nerve mandatory in thyroid operation? Results of a prospective randomized study

BACKGROUND

The aim of this study was to investigate the incidence of injury to the external branch of the superior laryngeal nerve (EBSLN) with 2 different surgical approaches.

METHODS

From 1998 to 2000, 289 consecutive patients undergoing thyroidectomy were randomly divided into 2 groups. In group A (137 patients [215 upper pole ligations]), the superior thyroid artery was ligated after identification of the EBSLN. In group B (152 patients [244 upper pole ligations]), the superior thyroid artery's branches were ligated separately close to the gland. In all patients, a phoniatric evaluation with videostrobolaryngoscopy and spectrographic examination was performed.

RESULTS

The 2 groups were well matched regarding age, sex, thyroid pathological findings, and type of operation. In group A, the EBSLN was not clearly identified in 11.6% of cases. Alterations of EBSLN function were absent in both groups of patients, either postoperatively or 1 and 6 months after operation. Group B showed statistically significant shorter operative time compared with that for group A.

CONCLUSIONS

Even if the EBSLN often crosses the superior thyroid pedicle, especially in large goiters, this study demonstrated that accurate distal ligation of the branches of the superior thyroid artery is a safe technique to prevent EBSLN injury.

Laparoscopic aortorenal bypass using a PTFE graft: survival study in the porcine model

PURPOSE

To verify the technical feasibility of laparoscopic aortorenal bypass in a porcine model and to evaluate renal pathologic findings after a short survival time.

MATERIALS AND METHODS

Laparoscopic aorta-to-left-renal artery bypass using an interposition Gore-Tex graft was performed in five animals. Renal function was assessed 1 week postoperatively and euthanasia performed after 14 days for histologic examination.

RESULTS

The median surgical time was 210 minutes (range 160-260 minutes). The median time needed to perform the aorta-to-graft anastomosis was 65 minutes (range 50-75 minutes), and the median time required to create the graft-to-renal artery anastomosis was 50 minutes (range 45-60 minutes). No conversion to open surgery was needed. Two intraoperative complications were observed: one large-bowel perforation, which was managed laparoscopically, and one obstruction of the aorta-to-graft anastomosis caused by clots, which was managed by removal of clots with a balloon catheter. No major postoperative complications were observed. The mean preoperative and postoperative serum creatinine concentrations were 0.8 +/- 1.2 and 0.7 +/- 1.6 mg/dL, respectively. At autopsy, all but one of the pigs were found to have a patent aortorenal bypass. In one pig, we found a partially clotted graft. Histologic examination demonstrated an unremarkable kidney in four cases and a kidney showing aspects of coagulative necrosis with viable cells in the animal with the partially clotted graft.

CONCLUSIONS

Laparoscopic aortorenal bypass is feasible. The short-term effect of the bypass on kidney vascularization seems promising, as demonstrated by pathologic findings. Laparoscopic aortorenal bypass could extend the indications for renal revascularization surgery.

Arterial PCO2 and cardiovascular function during endoscopic neck surgery with carbon dioxide insufflation

BACKGROUND

Endoscopic parathyroidectomy and thyroidectomy were introduced into clinical practice in 1995. Concerns about the use of carbon dioxide insufflation in the neck exist owing to reports of potential adverse metabolic and hemodynamic changes.

HYPOTHESIS

Carbon dioxide insufflation in the neck may cause adverse effects on hemodynamic and blood gas levels. These adverse effects may reflect the level of pressure and duration of insufflation.

METHODS

Fifteen pigs, 5 per group, underwent endoscopic thyroidectomy at 10, 15, and 20 mm Hg. Partial pressure of carbon dioxide (arterial), pH, cardiac output, central venous pressure, heart rate, and mean arterial pressure (MAP) were measured at baseline, 1 and 2 hours after carbon dioxide insufflation, and 30 minutes after desufflation.

RESULTS

At 10 mm Hg, PaCO2 increased slightly but not significantly, and neither acidosis nor adverse hemodynamic changes were observed. Hypercarbia, moderate acidosis, and a slight increase in MAP occurred in pigs undergoing surgery at 15 mm Hg (MAP increased to 88 +/- 2.4 mm Hg from a baseline value of 78 +/- 3.53 mm Hg; P<.05). Pigs undergoing surgery at 20 mm Hg experienced severe hypercarbia and acidosis, as well as a significant decrease in MAP (P<.05). Central venous pressure decreased at 1 hour (P<.05) and increased at 2 hours (P<.05) in pigs undergoing surgery at 15 and 20 mm Hg. After desufflation, PaCO2 and pH levels were normal for the 10 and 15 mm Hg groups, while pigs undergoing surgery at 20 mm Hg developed a higher degree of hypercarbia and acidosis (P =.001).

CONCLUSIONS

Carbon dioxide neck insufflation is safe at 10 mm Hg. The use of insufflation pressures higher than 15 mm Hg should be avoided due to the potential risk for metabolic and hemodynamic complications.

Hepatic outflow occlusion in laparoscopic hepatectomy

BACKGROUND

The application of laparoscopic techniques to major hepatic resection has been limited by the risk of hepatic vein laceration leading to massive bleeding or gas embolism. A balloon catheter has therefore been designed to occlude hepatic vein flow during experimental laparoscopic hepatectomy.

METHODS

The procedure was attempted in 8 pigs weighing around 50 kg and submitted to laparoscopic left hemihepatectomy. A specially designed balloon catheter was inserted via the femoral vein and advanced into the retrohepatic segment of inferior vena cava (IVC). After inflation of the balloon with 17 ml contrast, angiography confirmed complete occlusion of this segment, while a central rigid channel allowed passage of blood from IVC to right atrium. Haemodynamic studies were performed during resection of the left and left paramedial lobes of the liver, which was completed laparoscopically using ultrasonic coagulating shears and vascular linear staplers.

RESULTS

Inflation of the balloon reduced mean arterial pressure to 75-79% and central venous pressure to 29-42% of baseline values, while cardiac output also fell (to 69-73% of basal). IVC blood flow decreased to 58% and hepatic venous flow to only 16% of pre-inflation values. Left hemihepatectomy was successfully achieved by the laparoscopic route in all 8 animals with a mean balloon inflation time of 30 min and blood loss of 166 ml. Haemodynamic indices returned to normal after deflation of the balloon at the end of the resection.

DISCUSSION

This preliminary study shows that hepatic venous outflow can be occluded by this special balloon catheter and that animals can tolerate the associated haemodynamic disturbance. Similar techniques in man might permit major hepatectomy to be safely achieved by a laparoscopic approach.

Endoscopic endocrine neck surgery with carbon dioxide insufflation: the effect on intracranial pressure in a large animal model

BACKGROUND

Endoscopic endocrine neck surgery requires insufflation with carbon dioxide (CO(2)) at 10 to 15 mm Hg, which may decrease the cerebral venous return and increase intracranial pressure. This study evaluated the effect of CO(2) neck insufflation on intracranial pressure (ICP) and hemodynamic parameters.

METHODS

Fifteen pigs underwent endoscopic thyroid dissection. Insufflation was performed with CO(2) at 0 (sham), 10, 15, and 20 mm Hg and with helium at 20 mm Hg with 3 pigs in each group. ICP, mean arterial pressure, central venous pressure (CVP), cardiac output, and blood gas were measured at baseline, 30, 60, and 120 minutes.

RESULTS

There were no differences in mean ICP between the sham group and CO(2) insufflation at 10 mm Hg. Mean ICP increased significantly with CO(2) at 15 and 20 mm Hg and with helium at 20 mm Hg. A significant increase in CVP occurred in pigs operated with CO(2) at 20 mm Hg. We observed jugular vein collapse under all insufflation pressures; however, pigs operated at 10 mm Hg were able to maintain an intermittent blood flow.

CONCLUSIONS

A severe increase in ICP occurs with insufflation pressures higher than 15 mm Hg, possibly as a result of decreased cervical venous blood flow. Carbon dioxide insufflation up to 10 mm Hg does not alter ICP and is recommended for clinical application in endoscopic neck surgery.

Minimally invasive spine surgery: an animal model for endoscopic approach to the anterior cervical and upper thoracic spine

BACKGROUND

Minimally invasive video-assisted techniques are currently used for thoracic and lumbar spine surgery with the aim of reducing the morbidity. Recently, an endoscopic approach has been used for endocrine neck surgery, with reduced pain and improved cosmetic results.

PURPOSE

To develop an animal model for an endoscopic neck approach to the anterior cervical and upper thoracic spine.

METHODS

Five pigs were used. A combination of one 5- and two 3-mm laparoscopic instruments was used to dissect the spine, and dedicated instrumentation was then used to perform discectomies. Carbon dioxide was insufflated at 10 mm Hg. Dissection was carried out upward and downward on the anterior aspect of the spine; discectomy was performed at various levels and evaluated at autopsy.

RESULTS

All pigs tolerated the procedure well. Visibility of the cervical spine was excellent, and exposure from C1 to T3 was obtained. For discectomy, an additional 10-mm trocar was inserted, and discectomy of C3-C4 and C4-C5 was performed. Proper location and adequacy were confirmed at autopsy.

CONCLUSION

The endoscopic neck approach allows exposure of the entire cervical spine and the upper thoracic spine in the porcine model. This approach has the potential to reduce the morbidity associated with the open cervical approach and provides a wider view and exposure than conventional open surgery. The availability of the porcine model allows the acquisition of the necessary technical skills before introducing this advanced procedure in humans.

Review and case report of idiopathic lower extremity compartment syndrome and its treatment in diabetic patients

Diabetic muscle infarction is a rare complication of diabetes mellitus. However, idiopathic compartment syndrome in the diabetic patient is even a rarer disease, which has been reported only in three cases up to date. The disease seems to occur in patients affected by type 1 diabetes mellitus with a history of poorly controlled glucose levels. MRI aids in the diagnosis by delineating the edema of the muscle. However, definitive diagnosis is made using the Stryker needle unit. Treatment is accomplished by immediate two-incision fasciotomy. We present a case where a 34 yr-old female with a long standing history of poorly controlled Type 1 diabetes mellitus presented with a painful right lower extremity and was diagnosed with compartment syndrome. In our patient, a single incision fasciotomy to release the pressure was sufficient and might be considered as an alternative and less morbid procedure in the diabetic patient with already poorly healing tissues. We conclude that the muscle infarction in these patients is from diffuse microangiopathic disease leading to muscular infarction and fluid accumulation in the cells causing a decrease in the space in the compartment in question causing compartment syndrome.

Valsalva leak point pressure: how to chose the best method

Urinary continence is ensured as long as the urethral closure pressure remains greater than the intravesical pressure, in the presence of adequate support to the bladder and the proximal urethra. In order to select the appropriate surgical treatment, a correct diagnosis must be made; recently urodynamic evaluation has assumed a central role. In particular, the introduction of a new urodynamic parameter, the Valsalva Leak Point Pressure (VLPP), has provided new impetus to research in this area, even if different technical approaches have limited universal acceptance. The aim of the work is to describe the reasons why the authors have been led to prefer double measurement, both at partial filling and at maximum cystometric capacity, considering that this does not involve any additional economic burden. The authors underline the promising potential of the method, once standardized, in the urodynamic evaluation of urinary incontinence.

Minimally invasive, totally gasless video-assisted thyroid lobectomy

BACKGROUND

Neck surgery is one of the newest fields of application of video-assisted surgery. We developed a technique for minimally invasive, totally gasless video-assisted thyroid lobectomy.

METHODS

The procedure was accepted by a patient with a follicular nodule of the left lobe of the thyroid. We performed a left thyroid lobectomy through a single 20-mm horizontal skin incision, just above the sternal notch, after inserting a 5-mm 30 degrees laparoscope, by using both endoscopic and conventional instrumentation.

RESULTS

The recurrent laryngeal nerve and the parathyroid glands were easily identified and preserved. The operating time was 2.5 hours. No complication occurred. The postoperative stay was 2 days. The cosmetic result was excellent

CONCLUSIONS

We concluded that our technique is feasible and safe. This makes us optimistic about the future of minimally invasive, video-assisted thyroid surgery.

Prognostic factors in differentiated thyroid carcinoma: a multivariate analysis of 234 consecutive patients

BACKGROUND AND OBJECTIVES

The clinical characteristics and patient outcome of a group of patients treated for differentiated thyroid carcinoma (DTC) were analyzed in order to assess the relative influence of different prognostic factors.

MATERIALS AND METHODS

We retrospectively reviewed data about sex, age, size and histologic behavior of the tumor, extrathyroid extension of the tumor, lymph node status, distant metastasis at diagnosis, surgical procedures, and overall survival from 234 patients treated for DTC. Data were submitted to a statistical analysis.

RESULTS

Using a univariate analysis, we found that survival rates were significantly influenced by age (P = 0.0001), size (P = 0.018), extrathyroidal extension (P = 0.000001), lymph node involvement (P = 0.03), and distant metastases (P = 0.049). Age and size were independent prognostic factors at multivariate analysis (t = 2.694 and t = 2.443, respectively).

CONCLUSIONS

On the basis of our results and of a review of the literature, we conclude that total thyroidectomy is the treatment of choice in DTC, except for small (<1 cm) papillary carcinoma, that could be treated by lobectomy plus isthmectomy, while lymphadenectomy is indicated only in case of macroscopic involvement.

[Varicocele in young recruits]

The authors, after an examination of the literature on the subject, present the results of a retrospective study in which the incidence of varicocele among selected young soldiers population called up at SARVAM (Viterbo) from May 1993 until October 1995 is evaluated.

Increased transforming growth factor-beta1 plasma concentration is associated with high plasma 3,3',5'-tri-iodothyronine in elderly patients with nonthyroidal illnesses

OBJECTIVE

To study transforming growth factor-beta1 (TGF-beta1) plasma concentrations in elderly patients with nonthyroidal illnesses (NTI).

DESIGN

Case-control study.

METHODS

We measured plasma concentrations of tri-iodothyronine (T3), reverse T3 (rT3), thyroxine (T4), free T3 (fT3) and free T4 (fT4) estimates, TSH, and TGF-beta1 in 48 elderly NTI patients consecutively admitted in our Division of Internal Medicine and Metabolic Diseases, and in 11 healthy age- and sex-matched controls.

RESULTS

The data on thyroid hormones enabled us to identify three groups: Group A, subjects (8 patients) with T3 and fT3 levels comparable to those in controls: Group B, subjects (30 patients) with T3 and fT3 levels lower than controls but rT3 levels comparable to those of controls; Group C, subjects (10 patients) with T3 and fT3 levels lower than those of controls and higher rT3 levels. The patients of Group C showed higher plasma levels of TGF-beta1 compared with controls. Moreover, we found a positive correlation between TGF-beta1 and rT3 (rs = 0.38, P < 0.01) in the whole group of NTI patients.

CONCLUSIONS

Our data seem to confirm the hypothesis that TGF-beta1 could play a role in the pathogenesis of some modifications of thyroid function observed in patients with nonthyroidal illnesses.

Reduced plasma concentrations of transforming growth factor β1 (TGF-β1) in obese women

OBJECTIVE

To evaluate Transforming Growth Factor beta1, (TGF-beta1) plasma concentrations and the possible relationship between this growth factor and various hormones in obese women.

DESIGN

Case-control study.

SETTING

Outpatient's Service for the Prevention and Treatment of Obesity at the University Hospital.

SUBJECTS

Twenty-five women with mild to moderate obesity, and 15 non-obese healthy women were used as controls.

MEASUREMENTS

Evaluation of TGF-beta1, insulin, prolactin, sex-hormone binding globulin, androstenedione, free triiodothyronine, free tetraiodothyronine, thyroid-stimulating hormone, dehydroepiandrosterone-sulfate, testosterone, insulin-like growth factor 1, cortisol and adrenocorticotropic hormone plasma concentrations in obese women. Blood samples were taken from fasting subjects for the determination of the above parameters.

RESULTS

In obese women plasma TGF-beta1 concentrations were lower than in controls. The obese subjects also had lower GH, IGF-1 and SHBG plasma concentrations and increased insulinaemia. A positive correlation was found between TGF-beta1 and both IGF-1 (r = 0.52; P < 0.01) and DHEA-S (r = 0.43; P < 0.05), while a negative correlation was found between TGF-beta1 and SHBG (r = -0.49; P < 0.05).

CONCLUSIONS

The reduction in TGF-beta1, an antilipogenic factor, may play a role in the pathogenesis of obesity and could be involved in the development of some obesity-related endocrine alterations.