Factors influencing lower esophageal sphincter relaxation after deglutition

AIM:To study the relationship between upper esophageal sphincter (UES) relaxation,peristaltic pressure and lower esophageal sphincter (LES) relaxation following deglutition in non-dysphagic subjects.METHODS:Ten non-dysphagic adult subjects had a high-resolution manometry probe passed transnasally and positioned to cover the UES,the esophageal body and the LES.Ten water swallows in each subject were analyzed for time lag between UES relaxation and LES relaxation,LES pressure at time of UES relaxation,duration of LES relaxation,the distance between the transition level (TL) and the LES,time in seconds that the peristaltic wave was before (negative value) or after the TL when the LES became relaxed,and the maximal peristaltic pressure in the body of the esophagus.RESULTS:Relaxation of the LES occurred on average 3.5 s after the bolus had passed the UES and in most cases when the peristaltic wave front had reached the TL.The LES remained relaxed until the peristaltic wave faded away above the LES.CONCLUSION:LES relaxation seemed to be caused by the peristaltic wave pushing the bolus from behind against the LES gate.

Effects and mechanisms of electroacupuncture at PC6 on frequency of transient lower esophageal sphincter relaxation in cats

AIM: To investigate the effects of electroacupuncture (EA) at neiguan (PC6) on gastric distention-induced transient lower esophageal sphincter relaxations (TLESRs) and discuss the mechanisms of this treatment. METHODS: ProtocolⅠ: Twelve healthy cats underwent gastric distention for 60 min on the first day. Electrical acupoint stimulation was applied at the neiguan or a sham point on the hip in randomized order before gastric distention, on the third day and fifth day. Those cats that underwent EA at neiguan on the fifth day were named "Neiguan Group" and the cats that underwent EA at a sham acupoint on the fifth day were named "Sham Group" (control group). During the experiment the frequency of TLESRs and lower esophageal sphincter (LES) pressure were observed by a perfused sleeve assembly. Plasma levels of gastrin (GAS) and motilin (MTL) were determined by radioimmunoassay. Nitrite/nitrate concentration in plasma and tissues were measured by Griess reagent. The nuclei in the brain stem were observed by immunohistochemistry method of c-Fos and NADPH-d dyeing. Protocol Ⅱ: Thirty six healthy cats were divided into 6 groups randomly. We gave saline (2 mL iv. control group), phaclofen (5 mg/kg iv. GABA-B antagonist), cholecystokinin octapeptide (CCK-8) (1 μg/kg per hour iv.), L-Arginine (200 mg/kg iv.), naloxone (2.5 μmol/kg iv.) and tacrine (5.6 mg/kg ip. cholinesterase inhibitor) respectively before EA at Neiguan and gastric distention. And the frequencies of TLESRs in experimental groups were compared with the control group.RESULTS: ProtocolⅠ: Not only the frequency of gastric distention-induced TLESR in 60 min but also the rate of common cavity during TLESRs were significantlydecreased by EA at neiguan compared to that of sham acupoint stimulation. C-Fos immunoreactivity and NOS reactivity in the solitarius (NTS) and dorsal motor nucleus of the vagus (DMV) were significantly decreased by EA at neiguan compared to that of the sham group. However, the positive nuclei of C-Fos and NOS in reticular formation of the medulla (RFM) were increased by EA at neiguan. Protocol Ⅱ: The inhibited effect of EA at neiguan on TLESR’s frequency was completely restored by pretreatment with CCK (23.5/h vs 4.5/h, P < 0.05), L-arginine (17.5/h vs 4.5/h, P < 0.05) and naloxone(12/h vs 4.5/h, P < 0.05). On the contrary, phaclofen (6/h vs 4.5/h, P > 0.05) and tacrine (9.5/h vs 4.5/h, P > 0.05) did not influence it. CONCLUSION: Electric acupoint stimulation at Neiguan significantly inhibits the frequency of TLESR and the rate of common cavity during TLESR in cats. This effect appears to act on the brain stem, and may be mediated through nitric oxide (NO), CCK-A receptor and mu-opioid receptors. But the GABAB receptor and acetylcholine may not be involved in it.

Neuro-regulation of lower esophageal sphincter function as treatment for gastroesophageal reflux disease

The junction between the esophagus and the stomach is a specialized region, composed of lower esophageal sphincter (LES) and its adjacent anatomical structures, the gastric sling and crural diaphragm. Together these structures work in a coordinated manner to allow ingested food into the stomach while preventing reflux of gastric contents across the esophago-gastric junction (EGJ) into the esophagus. The same zone also permits retrograde passage of air and gastric contents into esophagus during belching and vomiting. The precise coordination required to execute such a complicated task is achieved by a finely-regulated high-pressure zone. This zone keeps the junction between esophagus and stomach continuously closed, but is still able to relax briefly via input from inhibitory neurons that are responsible for its innervation. Alterations of the structure and function of the EGJ and the LES may predispose to gastroesophageal reflux disease (GERD).

Investigation of cholecystokinin receptors in the human lower esophageal sphincter

AIM: To compare the binding of cholecystokinin (CCK)-8 to CCK receptors in sling and clasp fibers of the human lower esophageal sphincter.

In vitro effect of pantoprazole on lower esophageal sphincter tone in rats

AIM:To investigate the in vitro effects of pantoprazole on rat lower esophageal sphincter(LES)tone.METHODS:Rats weighing 250-300 g,provided by the Yeditepe University Experimental Research Center(Yü-DETAM),were used throughout the study.They were anesthetized before decapitation.LES tissues whose mucosal lining were removed were placed in a stan-dard 30-mL organ bath with a modif ied Krebs solution and continuously aerated with 95% oxygen-5% carbon dioxide gas mixture and kept at room temperature.The tissues were allowed to stabilize for 60 min.Sub-sequently,the contractile response to 10-6 mol/L carba-chol was obtained.Different concentrations of freshly prepared pantoprazole were added directly to the tis-sue bath to generate cumulative concentrations of 5×10-6 mol/L,5×10-5 mol/L,and 1.5×10-4 mol/L.Activi-ties were recorded on an online computer via a 4-channeltransducer data acquisition system using the software BSL PRO v 3.7,which also analyzed the data.RESULTS:Pantoprazole at 5×10-6 mol/L caused a small,but statistically insignif icant,relaxation in the car-bachol-contracted LES(2.23% vs 3.95%).The 5×10-5 mol/L concentration,however,caused a signif icant relax-ation of 10.47% compared with the control.1.5×10-4 mol/L concentration of pantoprazol caused a 19.89% relaxation in the carbachol contracted LES(P<0.001).CONCLUSION:This is the fi rst study to demonstrate that pantoprazole has a relaxing effect in isolated LESs.These results might have signif icant clinical implications for the subset of patients using proton pump inhibitors who do not receive full symptomatic alleviation from gastroesophageal reflux disease.

Lower esophageal sphincter relaxation is impaired in older patients with dysphagia

AIM: To characterize the effects of age on the mechanisms underlying the common condition of esophageal dysphagia in older patients, using detailed manometric analysis. METHODS: A retrospective case-control audit was performed on 19 patients aged ≥ 80 years (mean age 85 ± 0.7 year) who underwent a manometric study for dysphagia (2004-2009). Data were compared with 19 younger dysphagic patients (32 ± 1.7 years). Detailed manometric analysis performed prospectively included basal lower esophageal sphincter pressure (BLESP), pre-swallow and nadir LESP, esophageal body pressures and peristaltic duration, during water swallows (5 mL) in right lateral (RL) and upright (UR) postures and with solids. Data are mean ± SE; a P-value < 0.05 was considered significant. RESULTS: Elderly dysphagic patients had higher BLESP than younger patients (23.4 ± 3.8 vs 14.9 ± 1.2 mmHg; P < 0.05). Pre-swallow LESP was elevated in the elderly in both postures (RL: 1 and 4 s P = 0.019 and P = 0.05; UR: P < 0.05 and P = 0.05) and solids (P < 0.01). In older patients, LES nadir pressure was higher with liquids (RL: 2.3 ± 0.6 mmHg vs 0.7 ± 0.6 mmHg, P < 0.05; UR: 3.5 ± 0.9 mmHg vs 1.6 ± 0.5 mmHg, P = 0.01) with shorter relaxation after solids (7.9 ± 1.5 s vs 9.7 ± 0.4 s, P = 0.05). No age-related differences were seen in esophageal body pressures or peristalsis duration. CONCLUSION: Basal LES pressure is elevated and swallow-induced relaxation impaired in elderly dysphagic patients. Its contribution to dysphagia and the effects of healthy ageing require further investigation.

Effect of electrical stimulation of the lower esophageal sphincter in gastroesophageal reflux disease patients refractory to proton pump inhibitors

AIM: To evaluate the efficacy of lower esophageal sphincter(LES)-electrical stimulation therapy(EST) in a subgroup of patients that reported only partial response to proton pump inhibitors(PPIs) therapy, compared to a group of patient with complete response.METHODS: Bipolar stitch electrodes were laparoscopically placed in the LES and connected to an implantable pulse generator(EndoS tim BV, the Hague, the Netherlands), placed subcutaneously in the anterior abdominal wall. Stimulation at 20 Hz, 215 μsec, 3-8 m Amp in 30 min sessions was delivered starting on day 1 post-implant. Patients were evaluated using gastroesophageal reflux disease(GERD)-HRQL, symptom diaries; esophageal p H and esophageal manometry before and up to 24 mo after therapy and results were compared between partial and complete responders.RESULTS: Twenty-three patients with GERD on LESEST were enrolled and received continuous per-protocol stimulation through 12 mo and 21 patients completed 24 mo of therapy. Of the 23 patients, 16(8 male, mean age 52.1 ± 12 years) had incomplete response to PPIs prior to LES-EST, while 7 patients(5 male, mean age 52.7 ± 4.7) had complete response to PPIs. In the sub-group with incomplete response to PPIs, median(IQR) composite GERD-HRQL score improved significantly from 9.5(9.0-10.0) at baseline on-PPI and 24.0(20.8-26.3) at baseline off-PPI to 2.5(0.0-4.0) at 12-mo and 0.0(0.0-2.5) at 24-mo follow-up(P < 0.05 compared to on-and off-PPI at baseline). Median(IQR) % 24-h esophageal pH < 4.0 at baseline in this sub-group improved significantly from 9.8%(7.8-11.5) at baseline to 3.0%(1.9-6.3) at 12 mo(P < 0.001) and 4.6%(2.0-5.8) at 24 mo follow-up(P < 0.01). At their 24-mo follow-up, 9/11 patients in this sub-group were completely free of PPI use. These results were comparable to the sub-group that reported complete response to PPI therapy at baseline. No unanticipated implantation or stimulation-related adverse events, or any untoward sensation due to stimulation were reported in either group and LES-EST was safely tolerated by both groups. CONCLUSION: LES-EST is safe and effective in controlling symptoms and esophageal acid exposure in GERD patients with incomplete response to PPIs. These results were comparable to those observed PPI responders.

Nitric oxide activation of a potassium channel (BK_(Ca)) in feline lower esophageal sphincter

AIM:To assess the effect of nitric oxide (NO) on the large conductance potassium channel (BKCa) in isolated circular (CM) and sling (SM) muscle cells and muscle strips from the cat lower esophageal sphincter (LES) to determine its regulation of resting tone and relaxation.METHODS:Freshly enzymatically-digested and isolated circular smooth muscle cells were prepared from each LES region.To study outward K + currents,the perforated patch clamp technique was employed.To assess LES resting tone and relaxation,muscle strips were mounted in perfused organ baths.RESULTS:(1) Electrophysiological recordings from isolated cells:(a) CM was more depolarized than SM (-39.7 ± 0.8mV vs-48.1 ± 1.6 mV,P < 0.001),and maximal outward current was similar (27.1 ± 1.5 pA/pF vs 25.7 ± 2.0 pA/pF,P > 0.05);(b) The NO donor sodium nitroprusside (SNP) increased outward currents only in CM (25.9 ± 1.9 to 46.7 ± 4.2 pA/pF,P < 0.001) but not SM (23.2 ± 3.1 to 27.0 ± 3.4 pA/pF,P > 0.05);(c) SNP added in the presence of the BK Ca antagonist iberiotoxin (IbTX) produced no increase in the outward current in CM (17.0 ± 2.8 vs 13.7 ± 2.2,P > 0.05);and (d) L-NNA caused a small insignificant inhibition of outward K + currents in both muscles;and (2) Muscle strip studies:(a) Blockade of the nerves with tetrodotoxin (TTX),or BK Ca with IbTX had no significant effect on resting tone of either muscle;and (b) SNP reduced tone in both muscles,and was unaffected by the presence of TTX or IbTX.CONCLUSION:Exogenous NO activates BK Ca only in CM of the cat.However,as opposed to other species,exogenous NO-induced relaxation is predominantly by a non-BK Ca mechanism,and endogenous NO has minimal effect on resting tone.

Effect of 5-hydroxytryptamine Receptor in the Lower Esophageal Sphincter Regulation Mechanism

As a neurotransmitter and avascular active substance,the 5-hydroxytryptamine(5-HT,serotonin)is widely distributed in the central nervous system and surrounding tissues.The 5-HT can play its role by acting on its corresponding 5-HT receptor.Nowadays,the 5-HT receptor can be classified into seven,according to different signal transduction method of receptors,the 5-HT3 receptor belongs to the ligandgated ion channels,while other six 5-HT receptors are involved into the G protein-coupled receptors and play the biological role by binding to specific G protein-coupled receptors(GPCRs)on the surface of the cell membrane.The 5-HT plays an important role in the brain-gut information transmission and studies showed that the physiological stimulations like having meals,and pathological stimulations like ischemia and stress could promote the release of the 5-HT.In the gastrointestinal tract,the 5-HT is closely related to gastrointestinal sensitivity,gastrointestinal movement and secretion regulation,as well as many gastrointestinal dysfunction disorders,such as gastrointestinal power and visceral sensitivity abnormality and abnormalities of brain-gut axis.

Effects of 5-hydroxytryptamine Receptor on the Reaction of the Lower Esophageal Sphincter Under the Electrical Field Stimulation

In the first and second parts of this study,5-hydroxytryptamine(5HT)receptors,including 5-HT3 and 5-HT4 with the highest expression level,were found in clasp and sling fibres of the lower esophageal sphincter(LES).Specific 5-HT3 and 5-HT4 receptor agonists can induce the contraction effect of clasp and sling fibres of the LES while specific 5-HT7 receptor agonists showed no effects.In the study of this part,the in-vitro muscle tension measurement technology and EFS methods were used to detect the effect of the selective 5-HT receptor antagonist on the clasp and sling fibres of the in-vitro LES under the electrical field stimulation(EFS),and further to ensure the effect of 5-HT receptor in the LES neuroregulatory pathway,and deeply explore the effect of 5-HT receptor in the systolic and diastolic function regulation of the LES.

Effect of bilateral supraclavicular postoperative radiotherapy in middle and lower thoracic esophageal carcinoma

AIM: To evaluate whether postoperative radiotherapy is an alternative to neck lymph node surgery and if it provides a survival benefit for those receiving two-field, chest and abdomen, lymphadenectomy.

Thoracoscopic resection of a large lower esophageal schwannoma:A case report and review of the literature

BACKGROUND Esophageal schwannomas originating from Schwann cells are extremely rare esophageal tumors.They commonly occur in the upper and middle esophagus but less frequently in the lower esophagus.Herein,we report a rare case of a large lower esophageal schwannoma misdiagnosed as a leiomyoma.We also present a brief literature review on lower esophageal schwannomas.CASE SUMMARY A 62-year-old man presented with severe dysphagia lasting 6 mo.A barium esophagogram showed that the lower esophagus was compressed within approximately 5.5 cm.Endoscopy revealed the presence of a large submucosal protuberant lesion in the esophagus at a distance of 32-38 cm from the incisors.Endoscopic ultrasound findings demonstrated a 4.5 cm×5.0 cm hypoechoic lesion.Chest computed tomography revealed a mass of size approximately 53 mm×39 mm×50 mm.Initial tests revealed features indicative of leiomyoma.After multidisciplinary discussions,the patient underwent a video-assisted thoracoscopic partial esophagectomy.Further investigation involving immunohistochemical examination confirming palisading spindle cells as positive for S100 and Sox10 led to the final diagnosis of a lower esophageal schwannoma.There was no tumor recurrence or metastasis during follow-up.CONCLUSION The final diagnosis of esophageal schwannoma requires histopathological and immunohistochemical examination.The early appropriate surgery favors a remarkable prognosis.

The molecular pathogenesis of achalasia:a paired lower esophageal sphincter muscle and serum 4D label-free proteomic study

Background:Achalasia is a primary esophageal motility disorder with potential molecular pathogenesis remaining uncertain.This study aimed to identify the differentially expressed proteins and potential pathways among achalasia subtypes and controls to further reveal the molecular pathogenesis of achalasia.Methods:Paired lower esophageal sphincter(LES)muscle and serum samples from 24 achalasia patients were collected.We also collected 10 normal serum samples from healthy controls and 10 normal LES muscle samples from esophageal cancer patients.The 4D label-free proteomic analysis was performed to identify the potential proteins and pathways involved in achalasia.Results:Analysis of Similarities showed distinct proteomic patterns of serum and muscle samples between achalasia patients and controls(both P<0.05).Functional enrichment analysis suggested that these differentially expressed proteins were immunity-,infection-,inflammation-,and neurodegeneration-associated.The mfuzz analysis in LES specimens showed that proteins involved in the extracellular matrix–receptor interaction increased sequentially between the control group,type III,type II,and type I achalasia.Only 26 proteins altered in the same directions in serum and muscle samples.Conclusions:This first 4D label-free proteomic study of achalasia indicated that there were specific protein alterations in both the serum and muscle of achalasia,involving immunity,inflammation,infection,and neurodegeneration pathways.Distinct protein clusters between types I,II,and III revealed the potential molecular pathways associated with different disease stages.Analysis of proteins changed in both muscle and serum samples highlighted the importance of further studies on LES muscle and revealed potential autoantibodies.

Upper esophageal sphincter abnormalities on high-resolution esophageal manometry and treatment response of type Ⅱ achalasia

BACKGROUND Little is known about the clinical significance of upper esophageal sphincter(UES)motility disorders and their association with the treatment response of typeⅡachalasia.None of the three versions of the Chicago Classification of Esophageal Motility Disorders has defined UES abnormality metrics or their function.UES abnormalities exist in some patients and indicate a clinically significant problem in patients with achalasia.AIM To demonstrate the manometric differentiation on high-resolution esophageal manometry between subjects with abnormal UES and normal UES,and the association between UES type and the treatment response of typeⅡachalasia.METHODS In total,498 consecutive patients referred for high-resolution esophageal manometry were analyzed retrospectively.The patients were divided into two groups,those with normal and abnormal UES function.UES parameters were analyzed after determining lower esophageal sphincter(LES)function.Patients with typeⅡachalasia underwent pneumatic dilation for treatment.Using mixed model analyses,correlations between abnormal UES and treatment response were calculated among subjects with typeⅡachalasia.RESULTS Of the 498 consecutive patients,246(49.40%)were found to have UES abnormalities.Impaired relaxation alone was the most common UES abnormality(52.85%,n=130).The incidence rate of typeⅡachalasia was significantly higher in subjects with abnormal UES than those with normal UES(9.77%vs 2.58%,P=0.01).After pneumatic dilation,LES resting pressure,LES integrated relaxation pressure,and UES residual pressure were significantly decreased(41.91±9.20 vs 26.18±13.08,38.94±10.28 vs 16.71±5.65,and 11.18±7.93 vs 5.35±4.77,respectively,P<0.05).According to the Eckardt score,subjects with typeⅡachalasia and abnormal UES presented a significantly poorer treatment response than those with normal UES(83.33%vs 0.00%,P<0.05).CONCLUSION Impaired relaxation alone is the most common UES abnormality.The incidence of typeⅡachalasia is associated with abnormal UES.TypeⅡachalasia with abnormal UES has a poorer treatment response,which is a potentially prognostic indicator of treatment for this disease.

Upper esophageal sphincter abnormalities are strongly predictive of treatment response in patients with achalasia

AIM: To investigate the relationship between upper esophageal sphincter abnormalities achalasia treatment METHODS: We performed a retrospective study of 41 consecutive patients referred for high resolution esophageal manometry with a final manometric diagnosis of achalasia. Patients were sub-divided by presence or absence of Upper esophageal sphincter(UES) abnormality, and clinical and manometric profiles were compared.Correlation between UES abnormality and sub-type(i.e.,hypertensive, hypotensive or impaired relaxation) and a number of variables, including qualitative treatment response, achalasia sub-type, co-morbid medical illness,psychiatric illness, surgical history, dominant presentingsymptom, treatment type, age and gender were also evaluated.RESULTS: Among all 41 patients, 24(58.54%) had a UES abnormality present. There were no significant differences between the groups in terms of age, gender or any other clinical or demographic profiles. Among those with UES abnormalities, the majority were either hypertensive(41.67%) or had impaired relaxation(37.5%) as compared to hypotensive(20.83%), although this did not reach statistical significance(P = 0.42). There was no specific association between treatment response and treatment type received; however, there was a significant association between UES abnormalities and treatment response. In patients with achalasia and concomitant UES abnormalities, 87.5% had poor treatment response, while only 12.5% had favorable response. In contrast, in patients with achalasia and no UES abnormalities, the majority(78.57%) had good treatment response, as compared to 21.43% with poor treatment response(P = 0.0001). After controlling for achalasia sub-type, those with UES abnormality had 26 times greater odds of poor treatment response than those with no UES abnormality(P = 0.009). Similarly, after controlling for treatment type, those with UES abnormality had 13.9 times greater odds of poor treatment response compared to those with no UES abnormality(P = 0.017).CONCLUSION: The presence of UES abnormalities in patients with achalasia significantly predicted poorer treatment response as compared to those with normal UES function.

Tanshinone ⅡA improves functional recovery in spinal cord injury-induced lower urinary tract dysfunction

Tanshinone ⅡA, extracted from Salvia miltiorrhiza Bunge, exerts neuroprotective effects through its anti-inflammatory, anti-oxidative and anti-apoptotic properties. This study intravenously injected tanshinone ⅡA 20 mg/kg into rat models of spinal cord injury for 7 consecutive days. Results showed that tanshinone ⅡA could reduce the inflammation, edema as well as compensatory thickening of the bladder tissue, improve urodynamic parameters, attenuate secondary injury, and promote spinal cord regeneration. The number of hypertrophic and apoptotic dorsal root ganglion（L6–S1） cells was less after treatment with tanshinone ⅡA. The effects of tanshinone ⅡA were similar to intravenous injection of 30 mg/kg methylprednisolone. These findings suggested that tanshinone ⅡA improved functional recovery after spinal cord injury-induced lower urinary tract dysfunction by remodeling the spinal pathway involved in lower urinary tract control.

Botulinum Toxin A in the Treatment of Oropharyngeal or Esophageal Dysphagia

Objectives: In this retrospective analysis, we explored the effect of botulinum toxin A (BTA) injection to treat oropharyngeal dysphagia or esophageal dysfunction caused by diseases of the upper (UES) and lower (LES) esophageal sphincter. Methods: In total, 48 patients (17 patients with UES disorders, and 31 patients with LES dysfunction;mean age 64 years) were treated between 1996 and 2007 in our hospital. Comorbid diseases as well as maintenance medication were documented to evaluate the overall health status of our patients. The mean duration of symptoms, the number of pre-treatments and the specification of dysphagia were considered. Results: One month after injection, the response rates were 73.3% (UES group) and 76.6% (LES group). Most patients in the UES group received 30-40 units BTA (Botox?) whereas most patients in the LES group were treated with 100 units BTA. In cases of re-injection, 50% of patients in the UES group experienced an escalation of dosage (up to 75 units), whereas the other 50% received the same dosage. The dosages in the LES group were mostly kept constant. Conclusion: Comparing the two groups with esophageal dysfunction of fundamentally different etiologies (UES/LES), a discrepancy in the level of symptom relief, onset and a longer cessation of clinical benefit were observed in the LES group. In this analysis, we were able to show that injection of BTA is an effective and safe treatment for disorders of the UES and LES.

Stretta:A valuable endoscopic treatment modality for gastroesophageal reflux disease

One potential option for the management of refractory gastro-esophageal reflux disease(GERD)is the delivery of radiofrequency energy to the gastro-esophageal junction(Stretta).This endoscopic therapy is safe,effective,durable,and repeatable if necessary and serves an unmet need for many GERD sufferers.Stretta could be effective in decreasing esophageal sensitivity to acid and in decreasing the gastro-esophageal junction compliance,which in turn contributes to symptomatic benefit by decreasing refluxate volume.Therefore,Stretta may serve as an endoscopic pain modulator and should be considered in patients with refractory symptoms despite proton pump inhibitors,as well as in patients with functional heartburn.

Effects of anti-hypertensive drugs on esophageal body contraction

AIM:To clarify the effects of anti-hypertensive drugs on esophageal contraction and determine their possi-ble relationship with gastro-esophageal reflux disease.METHODS:Thirteen healthy male volunteers were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure were measured using high resolution manometry. All subjects were randomly examined on four separate occasions following administrations of nifedipine,losartan,and atenolol,as well as without any drug administration.RESULTS:Peristaltic contractions by the esophageal body were separated into three segments by two troughs. The peak peristaltic pressures in the mid and lower segments of the esophageal body under atenolol administration were signifi cantly higher than those without medication in a supine position. On the other hand,peristaltic pressures under nifedipine administration were lower than those observed without drug ad-ministration. Losartan did not change esophageal body peristalsis. Atenolol elevated LES pressure and slowed peristaltic wave transition,while the effects of nifedip-ine were the opposite. CONCLUSION:Among the anti-hypertensive drugs tested,atenolol enhanced esophageal motor activity,which was in contrast to nifedipine.

Magnetic challenge against gastroesophageal reflux

Almost 15 years have passed since the first paper on the possibility of using magnets to prevent gastro-esophageal reflux(GER)was published and so it is time to assess the results obtained with the first magnetic device available on the market,the Linx magnetic sphincter augmentation(MSA)and to consider what other options are forthcoming.MSA demonstrated an anti-reflux activity similar to that of Nissen fundoplication,considered the“gold standard”surgical treatment for GER disease,and caused less gas-bloating and a better ability to allow vomiting and belching.However,unlike Nissen fundoplication,this magnetic device is burdened by complications,which are roughly similar to those of the non-magnetic anti-reflux Angelchik prosthesis,that,after considerable use in the eighties,was shelved due to these complications.It is interesting to note that some of these complications show the same pathophysiological mechanism in both devices.The upcoming new magnetic devices should avoid these complications,as their anti-reflux magnetic mechanism is completely different.The experiments in animals regarding these new magnetic appliances were examined,remarking their advantages and drawbacks,but the way to apply them in surgical practice is long and difficult,although worthy,as they represent the future of magnetic surgery.