Robotic esophagomyotomy for achalasia: technical note and review of the literature

INTRODUCTION

The treatment of achalasia has undergone continuous evolution with the advancement of technology. Since the beginning of the new millennium, the employment of robotics has led to technical facilitation with the execution of the myotomy and consequently to improvement of outcomes and decrease perioperative morbidity.

EVIDENCE ACQUISITION

We provide a detailed description of the surgical procedure and the perioperative management together with a literature search of Electronic PubMed/Medline database and Cochrane Library. English written studies on robotic assisted myotomy (case reports, reviews, single arm and comparative studies) were included.

EVIDENCE SYNTHESIS

Between 2001 and 2020, 10 case reports, 13 single arm studies, 10 comparative studies, 2 meta-analysis, 11 reviews and 2 technical notes on robotic assisted esophagomyotomy for achalasia were published.

CONCLUSIONS

As reported by the studies available in the literature and evaluated in this manuscript, robotic assisted cardiomyotomy seems not only feasible but also a safer operation compared with traditional laparoscopic Heller myotomy, due to a significant lower incidence of intraoperative esophageal perforation. Also if large and randomized controlled studies are advocated, robotic assisted esophagocardiomyotomy might be considered superior to laparoscopic Heller myotomy that, until now, is mostly considered the gold standard in the surgical treatment of achalasia.

Hydrolysis of xylan at high temperature by co-action of the xylanase from Anoxybacillus flavithermus BC and the beta-xylosidase/alpha-arabinosidase from Sulfolobus solfataricus Oalpha

AIMS

It is evaluated the effectiveness of the combined action of two highly thermostable enzymes for the hydrolysis of xylans at high temperature in order to produce D-xylose.

METHODS AND RESULTS

Xylans from different sources were hydrolyzed at high degree at 70 degrees C by co-action of a xylanase from the thermophilic bacterium Anoxybacillus flavithermus BC and the novel beta-xylosidase/alpha-arabinosidase from the hyperthermophilic crenarchaeon Sulfolobus solfataricus Oalpha. Beechwood xylan was the best substrate among the xylans tested giving, by incubation only with xylanase, 32.8 % hydrolysis after 4 h. The addition of the beta-xylosidase/alpha-arabinosidase significantly improved the rate of hydrolysis, yielding 63.6% conversion after 4 h incubation, and the main sugar identified was xylose.

CONCLUSIONS

This study demonstrates that a significant degree of xylan degradation was reached at high temperature by co-action of the two enzymes. Xylose was obtained as a final product in considerable yield.

SIGNIFICANCE AND IMPACT OF THE STUDY

Although the xylan represents the second most abundant polysaccharide in nature, it still doesn't have significant utilization for the difficulties encountered in its hydrolysis. Its successful hydrolysis to xylose in only one stage process could make of it a cheap sugar source and could have an enormous economic potential for the conversion of plant biomass into fuels and chemicals.

Laparoscopic Conversion of an Omega in a Roux-en-y Reconstruction After Mini-invasive Total Gastrectomy for Cancer

INTRODUCTION

Few cases of laparoscopic total gastrectomy have been published. Reconstruction of the digestive tract was generally accomplished with a Roux-en-y esophagojejunal mechanical anastomosis. Here we report the first 2 cases of laparoscopic conversion of an omega in a Roux-en-y reconstruction due to the occurrence of a severe alkaline esophagitis after mini-invasive total gastrectomy for cancer.

MATERIALS AND METHODS

Two male patients presented in 2004. One year prior, at another facility, they had undergone laparoscopic total gastrectomy for cancer, with reconstruction of digestive tract by means of an esophagojejeunostomy with a jejunal loop and Braun's side-to-side enteroanastomosis. They complained of daily symptoms of nausea, regurgitation, heartburn, and early postprandial fullness with reduction of appetite and weight loss of almost 15 kg. Instrumental examination diagnosed alkaline esophagitis. Intervention was performed via laparoscopic approach and the digestive reconstruction was reconfigured in a Roux-en-y type with a proximal limb of almost 60 cm.

RESULTS

Operative time was 135 to 180 minutes. No postoperative complications occurred. After 1-year follow-up, symptoms resolution and esophagitis healing have been observed in both patients.

CONCLUSIONS

Laparoscopic gastrectomy is gaining wide acceptance. In our opinion, a standardization of the technique is necessary: we believe Roux-en-y should be considered the preferred reconstruction route ensuring the best protection of the esophagus from alkaline reflux.

The role of scintigraphic defecography in the assessment of bowel function after restorative proctocolectomy for ulcerative colitis

BACKGROUND

The aim of the study was to evaluate the efficiency of defecation in patients with ileal pouch for ulcerative colitis by using the mean of scintigraphic defecography.

METHODS

Sixteen patients were classified into two groups according to the presence of good (group A) or poor (group B) pouch function. Emptying efficiency was calculated by scintigraphic defecography and measured as percentage of evacuation. This involves the use of up to 200 ml of an artificial stool made up of methyl cellulose paste labeled with 180 MBq of technetium-99 m (Tc-99 m) methylene diphosphonate. Potential causes of increased frequency in the absence of additional associated symptoms of dysfunction were excluded in all patients. Maximum tolerated volume (MTV) and balloon expulsion tests were also performed on all patients.

RESULTS

No patient in both groups showed evidence of organic pouch dysfunction. Percentage of emptying was higher in patients of group A (n=6) than in group B (n=10) (81+/-9 vs 71+/-9%, respectively, P<0.05; correlation, -0.51, P<0.04). Mean MTV was similar in the two groups (group A: 361+/-118 ml and group B: 338+/-77 ml, P=0.7). Results of the balloon expulsion test were normal in all patients except for one individual in group B.

CONCLUSION

In patients with ileal pouch for ulcerative colitis, increased frequency of defecation without any evidence of pouch dysfunction may be correlated with an alteration of emptying efficiency. Scintigraphic defecography is appropriate to use for investigation of this condition with no disadvantages for the patients.

Gastroesophageal junction adenocarcinoma: what are the factors influencing long-term survival?

The incidence of gastroesophageal junction adenocarcinoma is increasing. About 30% of the tumors cannot be completely resected, and 40% of the patients relapse after complete resection. There is much controversy over the role of neoadjuvant therapy, the approach route, lymphadenectomy, and the extent of esophageal resection. The aim of our study was to report our experience in the treatment of gastroesophageal junction adenocarcinoma. From January 1987 until February 2005, 157 patients (125 men, 32 women), mean age 72.1 +/- 3.2 years, came for observation. One hundred sixteen patients underwent curative intervention. Mean operative time was 185 +/- 45 minutes. Mean postoperative hospital stay was 16.4 +/- 6.1 days. Postoperative complications were observed in 25 patients (21.6%); 6 patients (5.2%) died during the postoperative period. Overall survival was 36.2% and 27.6% at 3- and 5-year follow-up, respectively. Five-year survival rate was significantly lesser in R1/R2 versus R0 resections (0% versus 33.7%), N+ versus N- patients (11.3% versus 53.3%), and worsened with progression of pT histological staging (T1, 100%; T2, 24.1%; T3, 15.1%; T4, 0%). Determining prognostic factors are the radicality of resection, lymph nodal invasion, and histological staging.

A mesenteric window to approach a posterior side leak after laparoscopic assisted stapled strictureplasty for Crohn's disease

Strictureplasty leak in patients with Crohn's disease increases considerably morbidity rate. Intra-operative evaluation of the integrity of suture line and proficient management of any leakage after strictureplasty is mandatory to prevent post-operative complications. When a leakage is detected at the posterior side, through intra-operative insufflation or methylene blue test, it may be difficult to repair as the suture line is completely covered up by mesentery. The AA. describe the creation of a mesenteric window to reinforce the posterior side of a side-to-side stapled strictureplasty performed by laparoscopic assisted procedure. As far as we know, this new technical strategy may allow avoiding resection of small bowel.

Effects of short-chain fructo-oligosaccharides on glucose and lipid metabolism in mild hypercholesterolaemic individuals

BACKGROUND

The intake of 10 g/day of short-chain-fructo-oligosaccharides (sc-FOS) has been shown to increase significantly bifidus counts and to produce high amounts of short-chain fatty acids (SCFA), presumed to influence glucose and lipid metabolism.

AIM

To evaluate the effects of moderate intake of sc-FOS on glucose and lipid metabolism in individuals with mild hypercholesterolaemia.

DESIGN

A randomized double-blind sequential cross-over study.

SUBJECTS AND METHODS

Thirty subjects of both genders (20 M/10 F), mean age 45.5+/-9.9 years (M+/-SD), BMI 26.6+/-2.2 kg/m(2), with plasma cholesterol >5.17 and <7.76 mmol/l and plasma triglycerides <3.45 mmol/l, participated in the study. The study was performed after a wash-out period of 1 month and a run-in period of 1 month to stabilize patients on a standard diet (CHO 50%, fat 30%, protein 20%, fibre 20 g/day) plus placebo (maltodextrine plus aspartame 15 g/day). At the end of run-in, subjects were randomly assigned to receive sc-FOS (Actilight) (10.6g/day) or placebo (maltodextrine plus aspartame 15 g/day) with tea and/or coffee for a duration of 2 months and thereafter switched to the other treatment for additional 2 months. Plasma glucose, total and lipoprotein (VLDL, LDL, HDL) cholesterol and triglyceride concentrations were measured in the fasting state at the end of run-in and of each treatment period. At the end of the two treatment periods, patients consumed a standard test meal (protein 15%, carbohydrate 34%, fat 51%, kJ 3988) 1h after the administration of 5.3g of sc-FOS or placebo; plasma glucose, insulin, free fatty acid (FFA) and triglyceride responses to the test meal were evaluated.

RESULTS

No significant difference in fasting parameters was detected between the two treatments. After sc-FOS and placebo plasma cholesterol levels were, respectively, 6.47+/-0.70 and 6.44+/-0.78 mmol/l (n.s.) and plasma triglycerides were 1.53+/-0.71 and 1.56+/-0.53 mmol/l (n.s.). No significant differences were observed in cholesterol and triglyceride content of VLDL, LDL and HDL and in plasma Apo A1 levels; conversely, fasting plasma Lp(a) concentrations were significantly increased after sc-FOS (37+/-38 vs. 33+/-35 mg/dl; P<0.005). Postprandial responses of glucose, FFA and triglycerides were not significantly different between sc-FOS and placebo, while postprandial insulin response (incremental area) was significantly reduced after sc-FOS compared to placebo (14,490+/-7416 vs. 17,760+/-7710 pmol/l x 300 min; P<0.02).

CONCLUSIONS

A moderate intake of sc-FOS has no major effects on lipid metabolism, both in the fasting and in the postprandial period, in individuals with mild hypercholesterolaemia. A small but significant increase of Lp(a) concentrations was observed with sc-FOS consumption together with a reduction of the postprandial insulin response; however, the clinical relevance of these small effects is unclear.

In vitro reactivity of the antineoplastic drug carmustin and acrolein with model peptides

The in vitro interaction of the antineoplastic drug 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU) and acrolein with model peptides has been investigated in order to provide a detailed description of their electrophilic reactivity towards biological macromolecules. Following incubation with these substances, the modified species were separated by HPLC and identified by fast atom bombardment mass spectrometry, whereas the reactive amino acids within the peptide structure were assigned by tandem mass spectrometry. Incubation with BCNU led essentially to the formation of an N-terminal carbamoyl derivative that slowly decomposed to form three isomeric structures and a very minor ethylated adduct. Alkylation with acrolein gave rise to a mixture of different adducts due to the reaction of both the double bond and the carbonyl group. Two species containing intramolecular cross-links were also observed. These results constitute the prerequisite for in vitro and in vivo studies on the modification of haemoglobin in patients following treatment with antineoplastic drugs.

Structural characterization by mass spectrometry of hemoglobin adducts formed after in vivo exposure to methyl bromide

A mass spectrometric procedure is described for the structural study of the adducts formed in human hemoglobin by in vitro exposure of erythrocytes to the alkylating agent methyl bromide using different protein to reagent ratios. Peptide mapping by HPLC and tandem mass spectrometry allowed location of methylated amino acids within the protein sequence. A prominent reactivity of several nucleophilic side chains in human hemoglobin subunits was observed, which was modulated by the concentration of the alkylating agent. Cysteine residues, the main reactive sites, were fully methylated in hemoglobin exposed to a 10-fold excess of methyl bromide, differently from other residues, including histidines, showing a heterogeneous pattern of methylation that was largely directed by their environment. No evidence of methylation was found at the heme proximal histidines beta92 and alpha87. A more selective methylation was obtained when the ratio methyl bromide: hemoglobin was lowered to about 1:1. In this last case only specific residues were reactive. Among them, the N-terminal amino group of both alpha- and beta-globins, cysteine 104 in the alpha-chain and cysteine 93 (not cysteine 112) in the beta-chain, indicating a different accessibility to reaction of the sulfhydryl groups on the protein chain. Thus hemoglobin side chains are selectively modified and the degree of modification at each site is a function of the position of the single amino acid residue within the protein quaternary structure, raising the possibility that alterations of structure and functional properties of human hemoglobin following exposure to alkylating agents may be mediated through such covalent protein modifications. The results obtained demonstrate the usefulness of the analytical approach for the characterization of hemoglobin adducts with methyl bromide or similar compounds, which can constitute the basis for biomonitoring of human exposure.

Mass spectrometric analysis of haemoglobin adducts formed by methyl bromide in vitro

An analytical procedure is described for the identification of the adducts formed by interaction of methyl bromide and haemoglobin. The reaction products of in vitro incubation of haemoglobin with methyl bromide have been characterised by electrospray mass spectrometry and gas chromatography-mass spectrometry. A prominent reactivity of several potential nucleophilic sites of haemoglobin was observed. Analogous results were recorded on blood samples of workers exposed to methyl bromide. The results obtained represent the basis for the complete structural characterisation of the modified haemoglobin and demonstrate the usefulness of the proposed analytical approach for the evaluation of alkylation degree and the identification of modified amino acids in proteins.

Mass spectrometric analysis of rat hemoglobin by FAB-overlapping. Primary structure of the alpha-major and of four beta constitutive chains

1. The globin chain components of Sprague-Dawley rat hemoglobin were obtained by reverse-phase HPLC which showed the presence of two alpha-chain and four beta-chains. 2. The accurate molecular weight of each globin chain was determined by means of electrospray mass spectrometry. Extensive mass spectrometric analysis on several enzymatic digests by fast atom bombardment mass spectrometry (FAB-overlapping) meant to determine the complete sequence of the alpha-major and of the four beta-globins. 3. The primary structure of the alpha-major globin was found in agreement with literature data (Garrick et al., 1975 Biochem. J. 149, 245-258; Chua et al., 1987). 4. Sequence analysis of the four beta-globin chains showed that amino acid differences are restricted to two protein portions: the region 22-25 and 123-125, the remaining portions of the molecule being unchanged in the four globins. Furthermore, all the amino acid replacements correspond to single point DNA mutations and (with the exception of the substitution Asp 22-->Asn in the beta 2-globin) involve uncharged substitutions.

Study of interaction of styrene oxide with angiotensin by mass spectrometry

The present study describes how mass spectrometry was extensively applied to the characterization and quantification of modified amino acids within the polypeptide chain of Angiotensin I, chosen as model substrate, combining the use of fast atom bombardment mass spectrometry with gas chromatography--mass spectrometry. The reaction products after in vitro incubation of Angiotensin I with styrene oxide, a well known carcinogen, under different conditions, have been characterized: a prominent reactivity of several potential nucleophilic sites of Angiotensin I was shown, including two histidine residues and a tyrosine residue; it is worth noting that it has never been stated that tyrosine is highly reactive with styrene oxide. The results obtained demonstrate the usefulness of mass spectrometry for the structural determination of chemically modified amino acids in peptides and proteins, and the presence of a reliable relationship between reaction conditions and the production of alkylated amino acids. This characterization procedure offers the possibility of identifying reactive sites following exposure to unknown alkylating agents.