RESUMEN
BACKGROUND: Little grade A medical evidence exists to support the use of prosthetic material for hiatal closure. Therefore, the authors compiled and analyzed all the available literature to determine whether the use of prosthetic mesh in hiatoplasty for routine laparoscopic fundoplications (LF) or for the repair of large (>5 cm) paraesophageal hernias (PEH) would decrease recurrence. METHODS: A literature search was performed using an inclusive list of relevant search terms via Medline/PubMed to identify papers (n = 19) describing the use of prosthetic material to repair the crura of patients undergoing laparoscopic PEH reduction, LF, or both. RESULTS: Case series (n = 5), retrospective reviews (n = 6), and prospective randomized (n = 4) and nonrandomized (n = 4) trials were identified. Laparoscopic procedures (n = 1,368) were performed for PEH, gastroesophageal reflux disease (GERD), hiatal hernia, or a combination of the three. Group A (n = 729) had primary suture repair of the crura, and group B (n = 639) had repair with either interposition of mesh to close the hiatus or onlay of prosthetic material after hiatal or crural closure. The use of mesh was associated with fewer recurrences than primary suture repair in both the LF and PEH groups. The mean follow-up period did not differ between the groups (20.7 months for group A vs. 19.2 months for group B). None of the papers cited any instance of prosthetic erosion into the gastrointestinal tract. CONCLUSIONS: The current data tend to support the use of prosthetic materials for hiatal repair in both routine LF and the repair of large PEHs. Longer and more stringent follow-up evaluation is necessary to delineate better the safety profile of mesh hiatoplasty. Future randomized trials are needed to confirm that mesh repair is superior to simple crural closure.
Asunto(s)
Fundoplicación , Reflujo Gastroesofágico/cirugía , Hernia Hiatal/cirugía , Laparoscopía , Prótesis e Implantes , Mallas Quirúrgicas , Fundoplicación/métodos , Humanos , RecurrenciaRESUMEN
BACKGROUND: Thoracoscopic splanchnicectomy (SPL) has been reported to give excellent short-term pain relief in chronic pancreatitis. This study prospectively evaluates the long-term efficacy of SPL in pancreatitis patients. METHODS: Chronic pancreatitis patients with severe pain unrelieved by standard therapy completed a standard 10-point analogue pain scale prior to surgery and at postoperative visits. Midline and left-sided pain was treated with left SPL; right-sided pain was treated with right SPL. If pain recurred on the contralateral side, contralateral SPL was done. RESULTS: Fifteen patients underwent SPL. Eleven of them required narcotics preoperatively. Follow-up is complete and ranges from 4.2 to 6.1 years (median, 5.75). All patients had constant pain prior to surgery. Following SPL, it decreased in the short term to a mean of 3.9 attacks a month. At long-term follow-up, the mean number of attacks was 8.6 per month. Preoperatively, the mean score for worst pain within the last 2 months was 9.1. This score decreased to 3.9, but at long-term follow-up it had increased to near preoperative values (8.6). Current severity of pain decreased from 7.2 preoperatively to 2.9 at short-term follow-up, but at long-term follow-up it had increased. The degree of disability decreased from 9.1 preoperatively to 5.1 at short-term follow-up, but in the long term it increased toward preoperative values. Although eight patients were narcotic free at early follow-up, only three remained narcotic free in the long-term. CONCLUSION: Thoracoscopic SPL offers short-term relief of pain from chronic pancreatitis, but the relief is not durable in most cases. Similarly, there are short-term improvements in degree of disability, mood, and freedom from narcotic use that are not sustained in the long-term. Nevertheless, two-thirds of patients stated that they would have the surgery again.
Asunto(s)
Dolor Abdominal/cirugía , Pancreatitis/cirugía , Nervios Esplácnicos/cirugía , Toracoscopía/métodos , Dolor Abdominal/etiología , Adolescente , Adulto , Enfermedad Crónica , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Pancreatitis/complicaciones , Estudios Prospectivos , Resultado del TratamientoRESUMEN
BACKGROUND: The best technique for surgical esophagomyotomy to treat achalasia remains contentious. The controversies include the best approach (thoracoscopic or laparoscopic) and the need for an antireflux procedure. Postoperative pH studies have suggested pathologic gastroesophageal reflux (GER) in many cases; however, control studies of reflux patterns are scarce. This study presents pH studies before esophagomyotomy as well as long-term follow-up of patients undergoing esophagomyotomy. METHODS: Forty-nine patients underwent esophagomyotomy (45 thoracoscopically, 4 laparoscopically) for achalasia. Before treatment, 24-hour pH studies were conducted for 38 patients with achalasia. The patients were evaluated postoperatively for dysphagia and reflux. Results were classified as excellent, good, fair, or poor. RESULTS: The findings of the pretreatment pH studies were abnormal in 15 patients (39%). Twelve patients (32%) had GER either with esophageal fermentation (6 patients [16%]) or without fermentation (6 patients [16%]). Eight percent had esophageal fermentation alone. There was no correlation between GER and previous pneumatic dilatation. Twenty-three patients (60%) had normal pH scores; of these, 24% had esophageal fermentation, whereas 29% had neither reflux nor fermentation. Operative results were excellent in 70% of patients, good in 10%, and fair in 20%. All patients considered their conditions improved. Four patients required a subsequent operation because of dysphagia (n = 3) or reflux (n = 1), and their original procedures were classified as failures. Their current status is fair (n = 2), good (n = 1), and excellent (n = 1). GER was documented before the original operation in 3 of the 4 patients in whom the procedure failed. Fifteen patients were eligible for 5-year follow-up. Their results are excellent or good (n = 11) (73%) and fair (n = 4) (27%). CONCLUSIONS: A high percentage of patients with achalasia exhibit pathologic GER before surgical therapy and seem to be at higher risk for failed surgical treatment. Thoracoscopic esophagomyotomy resulted in improvement in 92% of patients, and long-term follow-up indicates that these results are durable.
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Acalasia del Esófago/cirugía , Esófago/cirugía , Reflujo Gastroesofágico/complicaciones , Toracoscopía , Adolescente , Adulto , Anciano , Estudios de Seguimiento , Determinación de la Acidez Gástrica , Humanos , Persona de Mediana EdadRESUMEN
Achalasia is characterized by the absence of peristalsis in the distal two thirds of the esophagus, failure of receptive relaxation of the lower esophageal sphincter, and dysphagia to both solids and liquids. Diagnosis is confirmed by barium swallow, esophageal manometry, and flexible endoscopy. Treatment is based primarily on disruption of the lower esophageal sphincter, which can be achieved by forceful dilation of surgical esophagomyotomy. Esophagomyotomy produces relief of symptoms in more than 90% of patients.
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Acalasia del Esófago/cirugía , Toracoscopía , Acalasia del Esófago/diagnóstico , Humanos , Toracoscopía/métodosRESUMEN
A review and updated report of an ongoing prospective investigation of two different adjustable silicone gastric banding devices is presented. One cohort of this study includes 40 subjects who have had a band placed by laparotomy. A second cohort includes 22 subjects who have had a newly designed adjustable silicone gastric band (ASGB) placed by laparoscopic or open technique. The goal of this investigation is to evaluate the achievement of sustained weight loss without the need for re-operation. Because of the frequent need for re-operation to correct life-threatening complications or ineffectiveness of ASGB devices, present clinical data indicate that improvements to the implantable system and the operative technique need to be made and verified by long-term study. At this point in development, ASGB remains an investigative procedure that has not fulfilled the scientific requirements of an accepted surgical treatment for severe obesity.
Asunto(s)
Gastroplastia/instrumentación , Obesidad Mórbida/cirugía , Siliconas , Estudios de Cohortes , Diseño de Equipo , Falla de Equipo , Estudios de Evaluación como Asunto , Estudios de Seguimiento , Gastroplastia/efectos adversos , Gastroplastia/métodos , Humanos , Laparoscopía , Laparotomía , Estudios Longitudinales , Estudios Prospectivos , Reoperación , Pérdida de PesoRESUMEN
The purpose of this study was to determine prospectively the safety and efficacy of an adjustable silicone gastric band and reservoir system for the treatment of morbid obesity. Between 1992 and 1995, forty primary procedures were performed. Twenty-six females and 14 males entered the study. The mean age of the subjects was 34 years (range 19 to 51 years). Mean body mass index was 50 kg/m2 (range 39 to 75 kg/m2). There were no deaths. Mean body mass index (in kg/m2) at follow-up visits was 38.4 at 1 year, 38.0 at 2 years, 40.2 at 3 years, and 40.4 at 4 years. These decreases were significant at P <0. 001. Thirty-two reoperations (12 intra-abdominal procedures and 20 abdominal wall procedures) have been necessary to maintain efficacy or correct complications. At the four-year interval, the reoperation rate of 80% was unsatisfactory. The excess weight loss has been 41% for those subjects who have an intact gastric band system and continue in the study. Improvements to the implantable band and/or operative technique must be implemented and studied long term if this procedure is to become an accepted surgical treatment for severe obesity.
Asunto(s)
Gastroplastia/efectos adversos , Obesidad Mórbida/cirugía , Pérdida de Peso , Adulto , Índice de Masa Corporal , Calibración , Ingestión de Energía , Diseño de Equipo , Falla de Equipo , Femenino , Estudios de Seguimiento , Gastroplastia/instrumentación , Gastroplastia/métodos , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Obesidad Mórbida/dietoterapia , Cuidados Posoperatorios , Estudios Prospectivos , Reoperación , Seguridad , Elastómeros de Silicona , Resultado del TratamientoRESUMEN
The objective of this paper is to summarize the goals, technical requirements, advantages, and potential risks of gastroplasty for treatment of severe obesity. Gastroplasty is preferred to more complex operations, as it preserves normal digestion and absorption and avoids complications that are peculiar to exclusion operations. The medical literature and a 30-year experience at the University of Iowa Hospitals and Clinics (UIHC) provides an overview of vertical banded gastroplasty (VBG) evolution. Preliminary 10-year results with the VBG technique currently used at UIHC are included. At UIHC the VBG is preferred to other gastroplasties because it provides weight control that extends for at least 10 years and the required objective, intraoperative quality control required for a low rate of reoperation. It is recommended that modifications of the operative technique not be attempted until a surgeon has had experience with the standardized operation--and then only under a carefully designed protocol. Realistic goals for surgery and criteria of success influence the choice of operation and the optimum, lifelong risk/benefit ratio. In conclusion, VBG is a safe, long-term effective operation for severe obesity with advantages over complex operations and more restrictive simple operations.
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Gastroplastia , Obesidad Mórbida/cirugía , Gastroplastia/métodos , HumanosRESUMEN
The usual available operating room table for general surgery procedures has a limitation of approximately 30 degrees ofhead up feet down tilt positioning. A recently developed accessory attachment for the Midmark 71OO General Surgery Table with the Extreme Reverse Trendelenburg Attachment (ERTA) has expanded the range ofhead up feet down tilt positioning to 62 degrees.
RESUMEN
BACKGROUND: Achalasia can be effectively treated by either hydrostatic balloon dilatation or transthoracic modified Heller myotomy. The purpose of this study was to determine whether thoracoscopic methods could be used to achieve surgical results equal to the transthoracic approach with less pain. METHODS: Twenty-one patients (10 men, 11 women; median age 42 years) had the diagnosis of achalasia confirmed by manometry, radiography, and endoscopy. All had dysphagia; five had weight loss. Median duration of symptoms was 12 months (range: 1 to 360 months). Eleven patients had undergone previous unsuccessful hydrostatic dilatation. Mean esophageal diameter was 5.5 +/- 2.2 cm. RESULTS: All patients underwent attempted modified Heller myotomy through a left thoracoscopic approach. Three patients required conversion to thoracotomy. The myotomy was extended < 1 cm past the squamocolumnar junction. There was one intraoperative perforation and no postoperative complications. All patients were begun on a regular diet on the first postoperative morning. Median length of stay was 2 days, Median follow-up was 22 months (range: 1 to 52 months). Sixteen patients (80%) had excellent relief of their dysphagia. Two patients (10%) had good relief, and two patients had only a fair result, although even they claim to be much improved. CONCLUSIONS: Thoracoscopic Heller myotomy reproduces the superior results of open esophagomyotomy with a reduced hospitalization and reduced incisional pain and disability.
Asunto(s)
Acalasia del Esófago/diagnóstico , Acalasia del Esófago/cirugía , Adulto , Anciano , Endoscopía , Acalasia del Esófago/diagnóstico por imagen , Femenino , Humanos , Masculino , Manometría , Persona de Mediana Edad , Dolor Postoperatorio/epidemiología , Dolor Postoperatorio/prevención & control , Radiografía , ToracoscopíaRESUMEN
BACKGROUND: The International (formerly National) Bariatric Surgery Registry began collecting data in January 1986. The aim of this study was to examine changes in the practice of surgical treatment of severe obesity that occurred during the decade of 1986 through 1995, as observed in the IBSR data. METHODS: All data submitted to the IBSR during the decade were transferred to the IBM mainframe computer for analysis. Characteristics of operative type populations were compared over time using analysis of variance (ANOVA) for age, body mass index (BMI), operative weight and Chi-square (chi2) test for gender. RESULTS: There has been a steady increase over the decade in mean patient weight. The operations used have changed from predominantly 'simple' operations to more frequent use of 'complex' operations. Within the categories of 'simple' and 'complex', an increase in the variety of operations occurred. As a group, patients with 'simple' operations have been heavier, more often male and public pay patients than those who have undergone 'complex' operations. One year weight loss was greater for Roux-en-Y gastric bypass (RGB) than vertical banded gastroplasty (VBG), but follow-up rates were too low to study the relative merits of the operations used. The reported incidence of operative mortality and serious complications (leak with peritonitis, abscess and pulmonary embolism) remained low. CONCLUSIONS: These observations and their implications can be summarized in three statements which relate to action for improved patient care in the beginning of the new century: (1) increasing weight of candidates for surgical treatment during this decade indicates the need for earlier use of operative treatment before irreversible complications of obesity can develop; (2) low risk of obesity surgery, decreasing postoperative hospital stay, and early weight control support the continued and increased use of surgical treatment; (3) continued widespread use of both 'simple' and 'complex' operations with increased modifications of standard RGB and VBG procedures emphasizes the need for standardized long-term data and analyses regarding both weight control and postoperative side-effects.
Asunto(s)
Obesidad Mórbida/cirugía , Adulto , Análisis de Varianza , Distribución de Chi-Cuadrado , Femenino , Estudios de Seguimiento , Gastroplastia/estadística & datos numéricos , Humanos , Masculino , Obesidad Mórbida/epidemiología , Complicaciones Posoperatorias/epidemiología , Sistema de Registros/estadística & datos numéricos , Factores de Riesgo , Factores de Tiempo , Pérdida de PesoRESUMEN
Esophageal perforation may occur spontaneously or as a complication of esophageal operations. Treatment often mandates emergency operative intervention to close the leak or to provide adequate drainage. Recurrent or persistent leak can lead to prolonged drainage before final healing. We describe herein a minimally invasive and inexpensive technique using fluorescein dye that can confirm the persistence of esophageal leak drained by tube thoracostomy without requiring expensive and potentially morbid invasive or radiological techniques. Application of this technique assists in diagnosis when previously described minimally invasive techniques are impractical or yield inconclusive results.
Asunto(s)
Perforación del Esófago/diagnóstico , Fluoresceínas , Colorantes Fluorescentes , Tubos Torácicos , Perforación del Esófago/terapia , Femenino , Fluoresceína , Humanos , Persona de Mediana Edad , ToracostomíaAsunto(s)
Esófago/anomalías , Esófago/cirugía , Gastroplastia/métodos , Laparoscopía/métodos , HumanosRESUMEN
BACKGROUND: The study was undertaken to quantitate the effects of thoracoscopic splanchnic nerve resection (SPL) on pain from chronic pancreatitis. METHODS: Patients with chronic pancreatitis pain completed an analog pain scale before operation and at postoperative visits. Midepigastric and left-sided pain was treated with left SPL; right-sided pain was treated with right-sided SPL. If pain recurred on the contralateral side, the patient underwent contralateral SPL. RESULTS: Fifteen patients underwent SPL. Eleven patients required daily narcotics for relief of pain before operation. Eight patients had unilateral SPL, whereas seven ultimately had a bilateral operation (median follow-up, 18 months). Fourteen patients had constant pain before operation, which decreased to a mean of 2.8 attacks per month (p < 0.0001). Before operation, the "worst pain within last two months" was 9.1 on pain scale (range, 0 for no pain, to 11 for constant pain). After operation this decreased to 5.1 (p < 0.002). "Current severity" of pain decreased from 6.5 before operation to 2.0 after operation (p < 0.0005). The "amount pain is interfering with daily activities" decreased from 7.3 before operation to 2.3 after operation (p < 0.0001). Seven patients (46%) no longer require narcotics and are classified as having had good results. Five patients (33%) are classified as improved and have had a major reduction in narcotic needs. Three have had no significant pain relief and are classified as having had poor results. CONCLUSIONS: Thoracoscopic SPL offers substantial promise in the therapy of pain from chronic pancreatitis.
Asunto(s)
Dolor/cirugía , Pancreatitis/complicaciones , Nervios Esplácnicos/cirugía , Adolescente , Adulto , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Narcóticos/administración & dosificación , Dolor/tratamiento farmacológico , Dolor/etiología , Dimensión del Dolor , Pancreatitis/mortalidad , Pancreatitis/cirugía , ToracoscopíaRESUMEN
BACKGROUND: Long-term complications of jejunoileal bypass (JIB) have been reported, prompting restoration of intestinal continuity and concomitant performance of vertical banded gastroplasty (VBG) for weight control. The aim of this study was to evaluate the presentation and reversal of JIB complications, late complications, mortality, and long-term weight control in patients who have undergone JIB reversal and concomitant VBG. STUDY DESIGN: From 1981 to 1994, 37 patients were treated for complications from JIB that included diarrhea (73 percent), arthritis (46 percent), malnutrition (22 percent), urolithiasis (19 percent), electrolyte disorders (19 percent), and lack of weight loss (8 percent). Four patients required preoperative parenteral nutrition to correct protein and electrolyte imbalances. Surgical management of all 37 patients included restoration of bowel continuity and VBG during the same operative procedure. RESULTS: Postoperative complications occurred in 11 patients, including prolonged ileus in seven patients, pancreatitis in three patients, and infectious complications in two. There were no deaths. Late morbidity included staple line dehiscence in four patients, incisional hernia in three patients, and reversal of the VBG in one. All patients with diarrhea, malnutrition, electrolyte disorders, and lack of weight loss had resolution of their symptoms, while urolithiasis and arthritis resolved in 86 and 53 percent of patients, respectively. In patients available for five-year follow-up evaluation, weight changes were small, shifting from a preoperative weight of 87 +/- 19 to 90 +/- 19 kg at five years (mean +/- SD). CONCLUSIONS: Restoration of intestinal continuity combined with VBG is a safe and effective operation that will reverse most of the long-term complications of JIB and provide stable weight control for up to five years.
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Gastroplastia , Derivación Yeyunoileal , Desequilibrio Ácido-Base/etiología , Desequilibrio Ácido-Base/prevención & control , Adulto , Artritis/etiología , Artritis/prevención & control , Peso Corporal , Diarrea/etiología , Diarrea/prevención & control , Estudios de Evaluación como Asunto , Femenino , Estudios de Seguimiento , Gastroplastia/efectos adversos , Hernia/etiología , Humanos , Obstrucción Intestinal/etiología , Derivación Yeyunoileal/efectos adversos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Trastornos Nutricionales/etiología , Trastornos Nutricionales/prevención & control , Pancreatitis/etiología , Reoperación , Dehiscencia de la Herida Operatoria/etiología , Infección de la Herida Quirúrgica/etiología , Tasa de Supervivencia , Resultado del Tratamiento , Cálculos Urinarios/etiología , Cálculos Urinarios/prevención & controlRESUMEN
Distal esophageal sensory nerves were stimulated in 17 anesthetized dogs divided into three age groups to determine the laryngeal, cardiovascular, and respiratory effects. Group I puppies were 5 to 6 weeks of age, group II puppies were 8 to 19 weeks of age, and group III animals were adult dogs. Marked laryngeal adductor activity and laryngospasm were observed in group II puppies, while no or minimal laryngeal adduction was seen in younger puppies and adult dogs. Mean arterial pressure and heart rate increased significantly in groups II and III (P < .005) but remained unchanged in group I animals (P > .4). This response is distinctly different from the laryngeal chemoreflex because central apnea, hypotension, and bradycardia were absent. The afferent limb of the response is mediated by the vagus nerve as bilateral transthoracic truncal vagotomy eliminated the reflex. The laryngeal response observed following stimulation of distal esophageal afferent fibers may be important in the mechanism of apparent life-threatening events (ALTEs) and the sudden infant death syndrome (SIDS) associated with gastroesophageal reflux disease.
Asunto(s)
Envejecimiento/fisiología , Esófago/inervación , Laringismo/etiología , Neuronas Aferentes/fisiología , Reflejo/fisiología , Vías Aferentes/fisiología , Animales , Presión Sanguínea/fisiología , Capsaicina/farmacología , Perros , Electromiografía , Reflujo Gastroesofágico/complicaciones , Frecuencia Cardíaca/fisiología , Humanos , Lactante , Laringismo/fisiopatología , Neuronas Aferentes/efectos de los fármacos , Estimulación Química , Muerte Súbita del Lactante/etiología , Vagotomía Troncal , Nervio Vago/fisiologíaRESUMEN
Systemic and local responses mediated by chemonociceptive receptors located in the mucosa of the canine distal esophagus were examined following stimulation with capsaicin (8-methyl-N-vanillyl-6-nonenamide). The neural pathways and neurotransmitters mediating these sensory responses were also investigated. Topical application of capsaicin solution to the distal esophageal mucosa produced significant increases in lower esophageal sphincter pressure (LESP), mean arterial pressure (MAP), pulse rate (PR), and respiratory rate (RR) (P < 0.01). Pretreatment with tetrodotoxin completely abolished this reflex activity. Following truncal vagotomy and pyloroplasty, topical capsaicin application produced an increase in LESP, but the increases in MAP, PR, and RR were blocked. The initial increase in LESP was blocked by hexamethonium, atropine, and 4-diphenylacetoxy-N-methylpiperidine, but was not inhibited by phentolamine. Excitatory cardiovascular responses were inhibited by hexamethonium. Administration of a Substance P antagonist attenuated both local and systemic responses. These studies suggest that the vagus nerves serve as the primary afferent pathways through which chemonociceptive esophageal stimuli can induce cardiovascular and respiratory reflex excitation. The increase in lower esophageal sphincter pressure in response to mucosal capsaicin stimulation is mediated via an intrinsic neural pathway that functions independently of vagal innervation, but is dependent on both cholinergic ganglionic neurotransmission and muscarinic type 2 smooth muscle receptor excitation. Substance P appears to play a role in primary sensory afferents as a chemonociceptive neurotransmitter in the canine distal esophagus.
Asunto(s)
Vías Aferentes/fisiología , Células Quimiorreceptoras/fisiología , Esófago/inervación , Animales , Atropina/farmacología , Presión Sanguínea/efectos de los fármacos , Capsaicina/farmacología , Perros , Esófago/efectos de los fármacos , Esófago/fisiología , Hexametonio , Compuestos de Hexametonio/farmacología , Membrana Mucosa/efectos de los fármacos , Membrana Mucosa/fisiología , Nociceptores/fisiología , Piperidinas/farmacología , Presión , Pulso Arterial/efectos de los fármacos , Respiración/efectos de los fármacos , Sustancia P/antagonistas & inhibidores , Tetrodotoxina/farmacología , VagotomíaRESUMEN
The specific functions of the numerous substance P (SP) nerve fibers present within the gastrointestinal tract are not clearly defined. This study examines both functional aspects and distribution of immunoreactive SP (IR-SP) in the canine gastroesophageal junctional (GEJ) region. Lower esophageal sphincter pressure (LESP), mean arterial pressure (MAP), pulse rate (PR), and respiratory rate (RR) were monitored before and after topical application of 2 ml capsaicin (8-methyl-N-vanillyl-6-nonenamide) to the distal esophageal mucosa of anesthetized dogs. Animals then underwent a capsaicin desensitization protocol over a 12-day period. The responses of monitored variables were compared on Day 1 and Day 12 of repetitive capsaicin application. Immunohistochemistry and radioimmunoassay (RIA) were performed on GEJ segments to study the distribution and content of IR-SP in both control (untreated) and capsaicin-treated dogs. The IR-SP was extracted from tissue for RIA and analysis by reverse-phase high-performance liquid chromatography (HPLC). On Day 1, a 2-ml capsaicin application stimulated increases in LESP (44.3 +/- 7.8 cm H2O; P < 0.05), MAP (48 +/- 8.7 mm Hg; P < 0.05), PR (52.6 +/- 20.5 beats/min; P < 0.05), and RR (26.3 +/- 15.6 breaths/min; P > 0.2). No response was observed on Day 12 of treatment. This was accompanied by a 43.3% decrease of IR-SP content in the mucosa of the distal esophagus of desensitized animals. Capsaicin applied at greater concentrations on Day 12 stimulated a return of responses (P < 0.05). Ganglia, cell bodies, nerve fascicles, and neurites stained positively for IR-SP. IR-SP content was markedly higher in esophageal mucosa than in gastric mucosa (P < 0.05). The authenticity of the IR-SP molecule was confirmed by elution time on HPLC. In conclusion, repetitive capsaicin application induced a state of homologous desensitization which was accompanied by a partial depletion of mucosal SP. The GEJ region contains a high SP content with a broad neural distribution. These findings are consistent with the hypothesis that SP may act as a neurotransmitter for chemonociceptive stimuli in the canine distal esophagus.
Asunto(s)
Esófago/fisiología , Estómago/fisiología , Sustancia P/fisiología , Animales , Presión Sanguínea/efectos de los fármacos , Capsaicina/farmacología , Cromatografía Líquida de Alta Presión , Perros , Esófago/química , Esófago/inervación , Inmunohistoquímica , Membrana Mucosa/efectos de los fármacos , Membrana Mucosa/fisiología , Neuronas/química , Presión , Pulso Arterial/efectos de los fármacos , Radioinmunoensayo , Respiración/efectos de los fármacos , Estómago/química , Estómago/inervación , Sustancia P/análisisRESUMEN
BACKGROUND: An increase in esophageal mucosal blood flow (MBF) may be an important protective mechanism against mucosal injury from noxious agents that are ingested or refluxed. This study investigated the changes in MBF and the regulation thereof after intraluminal application of noxious chemical stimuli. The role, if any, of substance P (SP) and nitric oxide (NO), two potent vasodilatory substances, and the vascular distribution of SP in the distal esophagus were evaluated. METHODS: Esophageal MBF was measured in anesthetized dogs with a laser Doppler flow probe attached to manometry and pH probes. MBF was measured before and after topical application of HCl (2 ml; 1N) or capsaicin (2 ml; 0.5%) in the distal esophagus. The effects on MBF of intraarterial SP and bradykinin were also determined. Pharmacologic antagonists and denervation procedures were used to delineate the mechanisms that regulate MBF. RESULTS: Sequential luminal applications of hydrochloric acid (HCl) or a single application of capsaicin increased MBF (p < 0.01). Topical intraluminal lidocaine blocked the response to capsaicin (p > 0.2) but not to HCl (p < 0.05). Abrupt increases in MBF occurred with intraarterial SP or bradykinin (p < 0.01). Neither atropine nor truncal vagotomy blocked the increase in MBF from these peptides or noxious stimuli. The NO synthesis antagonist NG-nitro-L-arginine methyl ester (L-NAME) blocked the response to bradykinin and attenuated the response to HCl (p < 0.05). NG-nitro-L-arginine methyl ester did not affect the response to SP or capsaicin. A substance P antagonist blocked the effects of both capsaicin (p > 0.6) and SP (p > 0.1) but not that of HCl (p < 0.01) or bradykinin (p > 0.01). CONCLUSIONS: Intraluminal applications of HCl or capsaicin appear to stimulate increases in esophageal MBF by different mechanisms. HCl produces an adaptive response that appears dependent on the paracrine effect of NO. Capsaicin-sensitive neurons mediate vasodilation through SP neurotransmission, independent of extrinsic vagal or cholinergic innervation.