Gastric Vagotomy Research Articles

Site-specific formation of thyrotropin-releasing hormone-induced gastric ulcers through the vagal system.

The left and right dorsal motor nuclei (DMN) separately innervate the anterior and posterior gastric walls through the left and right gastric branches of the vagus nerve (GBVN) in rats. The present study was carried out to investigate the effects of selective centrally originated excitation of the unilateral vagal system on the gastric area in which vagus-induced gastric ulcers developed. Since intracisternally injected thyrotropin-releasing hormone (TRH) stimulates neurons in the bilateral DMNs to produce gastric ulcers, selective stimulation of the unilateral vagal system was produced by contralateral gastric branch vagotomy before intracisternal injection of TRH. Intracisternal injection of TRH (2 micrograms/rat) into left gastric branch-vagotomized rats resulted in lesion formation only on the posterior gastric wall and not on the anterior wall. In contrast, in right gastric branch-vagotomized rats TRH-induced gastric lesions were observed only on the anterior gastric wall and not on the posterior wall. These results suggest that selective stimulation of the left or right DMN induces site-specific ulcer formation through the left or right GBVN. Next, gastric acid secretion was determined in pylorus-ligated rats to examine a role of acid hypersecretion in site-specific ulcer formation caused by TRH. Of interest was that gastric acid secretion in unilaterally vagotomized rats given TRH intracisternally was significantly smaller than that in sham-operated rats given intracisternal saline, although the former rats developed gastric ulcers, whereas the latter did not. It is therefore speculated that gastric hyperacidity plays a less important role in the peripheral mechanisms of TRH-induced site-specific gastric ulceration.

腹腔鏡下Ｔａｙｌｏｒ法迷走神経切離術の１例

われわれは本邦ではじめての腹腔鏡下Taylor法迷走神経切離術 (後幹切離+胃小彎前壁漿膜筋層切開) を施行したので報告する.患者は19歳の男性で, 14か月にわたりプロトンポンプ・インヒビターまたはH2ブロッカーを含む抗潰瘍薬による治療を継続したが, 十二指腸潰瘍の再発を繰り返したため, 迷走神経切離術の適応と考え手術を施行した.上腹部に挿入した5本のトラカールから腹腔内の操作を行った.まず食道裂孔部で迷走神経後幹を切離した.次に小彎線から1.5～2cm離れた胃前壁で, crow'sfootの口側枝からHis角の後壁に至る範囲の漿膜筋層を切開した.切開部は縫合, 閉鎖した.手術時間は3時間30分であった.術後胃排出能障害はみられず, 内視鏡検査では十二指腸潰瘍は瘢痕治癒していた.胃酸分泌検査ではBAOおよびMAOの減酸率はそれぞれ93.3%, 88.3%と良好であった.

The role of blood flow in gastric mucosal defence, damage and healing.

Blood flow plays an important role in protection of normal gastric mucosa and in the protection and healing of damaged mucosa. Blood flow contributes to protection by supplying the mucosa with oxygen and HCO3-, and by removing H+ and toxic agents diffusing from the lumen into the mucosa. Low mucosal blood flow predisposes to injury, whereas high blood flow protects against injurious agents. Superficial mucosal damage is followed by increased blood flow which supports the healing process and prevents superficial lesions from developing into deep ones. The hypermic response increases the supply of HCO3- to the mucosa and increases the resistance of the injured mucosa against back diffusing H+ and aggressive drugs such as ethanol (adaptive protection). Mucosal ischemia contributes to gastric ulceration in various clinical conditions such as hemorrhagic shock, stress, aorta aneurysm and after proximal gastric vagotomy. Blood vessels are damaged in gastric ulcers. During ulcer healing blood flow returns to normal. Stimulated or inhibited angiogenesis in the granulation tissue effects the healing of a gastric ulcer.

Gastric branch vagotomy blocks nutrient and cholecystokinin-induced suppression of gastric emptying

Pages R630–R637: G. J. Schwartz, G. Berkow, P. R. McHugh, and T. H. Moran. “Gastric branch vagotomy blocks nutrient and cholecystokinin-induced suppression of gastric emptying.” Page R361: An incorrect formula was used to calculate the volume remaining. The correct formula appears below. V = (Cs/Ci){[5/(1 – Co/Cs)] – 5} where Cs, is the concentration of dye in the stomach before saline rinse. The other factors remain as described in the article. This error resulted in a small underestimation of the magnitude of the reported phenomena in a few cases and does not alter the main findings, conclusions, or interpretations of this study.

Kainic acid injection into medullary raphe produces gastric lesions through the vagal system in rats

There is little evidence of a role of nuclei in the brain stem, other than the dorsal motor nucleus of the vagus nerve in the medulla oblongata, in terms of central mechanisms for gastric ulcer formation. Recent reports suggest that the medullary raphe nuclei may be involved in the central regulation of gastric functions such as gastric acid secretion and motility. In the present study, we examined whether neurons in the nucleus raphe obscurus (NRO) played a significant role in the formation of gastric ulcers with the use of Sprague-Dawley rats. First, we determined whether excitation of the medullary raphe resulted in the development of gastric lesions. Chemical stimulation of neurons in the NRO by kainic acid produced gastric erosions within 4 h in 24-h fasted rats. Saline tested under the same conditions did not modify the integrity of the gastric mucosa. It was also demonstrated that kainic acid injection outside the raphe obscurus boundaries failed to develop gastric lesions. Next, we examined the effects of the vagal system on the gastric lesion formation induced by stimulation of the raphe nucleus. Bilateral gastric branch vagotomies completely prevented the development of the raphe nucleus-provoked gastric mucosal damage. All these results suggest, for the first time, that excitation of neurons in the medullary raphe obscurus induces gastric ulceration through vagal stimulation.

Gastric branch vagotomy blocks nutrient and cholecystokinin-induced suppression of gastric emptying

A role for the vagus nerve in the emptying of intragastric nutrients and the gastric inhibitory actions of the brain-gut peptide cholecystokinin (CCK) has been proposed. To directly assess the role of the gastric vagal branches in these actions, we compared the emptying of 5-ml nutrient and nonnutrient gastric loads in male rats in which both branches of the gastric vagus nerves were cut (GVX, n = 7) with emptying in surgical control (n = 8) rats. Gastric emptying of saline was also examined in both groups after intraperitoneal administration of 8 micrograms/kg CCK. In control rats, high osmolarity, low pH, and caloric density all significantly decreased gastric emptying compared with the emptying of physiological saline. In addition, fat (oleic acid) and protein (peptone) loads emptied significantly more slowly than isocaloric carbohydrate (glucose) loads. Gastric branch vagotomy completely blocked the suppression of emptying produced by fat, protein, carbohydrate, and acid loads. In addition, GVX attenuated the ability of hyperosmotic nutrient and nonnutrient loads to inhibit emptying to the same degree, irrespective of their caloric content. Finally, in intact rats, CCK significantly inhibited the emptying of physiological saline, and gastric vagotomy abolished this suppression. Taken together, these results are consistent with the proposals that 1) the controlled emptying of caloric, hyperosmotic, and acidic solutions is dependent on gastric vagal branches, and 2) exogenous CCK relies on an intact vagal pathway in the control of gastric emptying.

Gastric branch vagotomy blocks nutrient and cholecystokinin-induced suppression of gastric emptying

Pages R630–R637: G. J. Schwartz, G. Berkow, P. R. McHugh, and T. H. Moran. “Gastric branch vagotomy blocks nutrient and cholecystokinin-induced suppression of gastric emptying.” Page R361: An incorrect formula was used to calculate the volume remaining. The correct formula appears below. V = (Cs/Ci){[5/(1 – Co/Cs)] – 5} where Cs, is the concentration of dye in the stomach before saline rinse. The other factors remain as described in the article. This error resulted in a small underestimation of the magnitude of the reported phenomena in a few cases and does not alter the main findings, conclusions, or interpretations of this study.

Influence of different methods of vagotomies on the secretion of cholecystokinin in dogs.

In six dogs, a selective proximal vagotomy, gastric vagotomy, and truncal vagotomy were performed successively. Basal and postprandial cholecystokinin (CCK) concentrations in the peripheral blood were measured by radioimmunoassay. After all the different types of vagotomy, especially after truncal vagotomy, an increased postprandial secretion of CCK was found compared with the healthy animal. Possible causes discussed are the cutting of vagal fibers, which might inhibit the secretion of CCK cells, and the changed gastric and pancreatic secretion.

Total gastric vagotomy, but not selective gastric vagal deafferentation, blocks CCK suppression of food intake

Total gastric vagotomy, but not selective gastric vagal deafferentation, blocks CCK suppression of food intake

Gastric vagotomy blocks opioid analgesia enhancement produced by placenta ingestion

Ingestion of amniotic fluid or placenta by rats has been shown to enhance opioid-mediated analgesia induced by morphine injection, footshock, vaginal/cervical stimulation, or late pregnancy. This enhancement by ingestion appears to be specific to the central actions of opioids. The present study was designed to examine the possibility that information traveling via the vagus nerve might be involved in mediating this effect. Rats that had undergone either selective gastric vagotomy or sham vagotomy were injected with either morphine sulfate or vehicle and fed either placenta or a meat control. Enhancement was observed in rats that had undergone sham vagotomy but not in those that had undergone gastric vagotomy. These results support an interpretation of vagal involvement in the enhancement of opioid-mediated analgesia by placenta.

Effect of gastric stimulants on histamine release and circulatory responses

The effects of pentagastrin (6 μg/kg/h) or insulin (0.15 U/kg/h) on histamine release and blood circulation in nine anaesthetized dogs were studied by measuring (1) plasma histamine concentrations in the iliac artery, iliac vein, hepatic vein and portal vein, (2) the corresponding blood pressures, and (3) blood flow in the hepatic artery and the portal vein. In the portal vein, pentagastrin induced an overall 204% rise (p<0.01) in plasma histamine and a 28% rise (p<0.01) in blood flow while other measurements did not change significantly. Insulin did not induce similar rises. Three patients with duodenal ulcer (DU) undergoing proximal gastric vagotomy (PGV) were given pentagastrin (6 μg/kg) by bolus injection. Plasma histamine concentrations in the gastric veins draining the oxyntic cell area rose by 68%, 15 min after injection. Thus, specific histamine release may act as a mediator for pentagastrin-stimulated gastric acid secretion and as a vasodilator to facilitate gastric circulation. Insulin did not promote histamine release in the present study.

Prospective comparison of Congo red and sham feeding testing to determine vagal innervation of the stomach

The purpose of this study was to validate Congo red (CR) testing as a means of determining the status of vagal innervation of the stomach after gastric surgery by comparing it with the sham feeding test (SF). Twenty-six patients with previous gastric operations were studied prospectively. The operations were vagotomy/antrectomy (n = 14), vagotomy/ antrectomy/Roux-en-Y anastomosis (n = 4), proximal gastric vagotomy (n = 3), vagotomy/pyloroplasty (n = 2), and antireflux (n = 3). In each case, the CR test was performed prior to the SF test so that the endoscopist was unbiased. The CR test solution was sprayed on the gastric mucosa through a wash catheter and immediately aspirated. A two-dimensional map of the endoscopist's conception of the red and black mucosa was drawn, and areas were calculated using a computerized scanner. The SF test was performed as described previously, with sham/peak ratios (sham feeding stimulated acid output [SAO]/peak acid output [PAO]) greater than 0.1 indicating a positive test, or incomplete vagotomy. The CR test was negative in 11 patients and positive in 15 patients. SF was negative in 16 patients (SAO/PAO of less than 0.1) and positive in 10 patients. The results correlated in 18 of 26 (69%) patients (p = not significant). Positive sham feeding tests and negative Congo red tests were more reliable, whereas negative sham feeding tests and positive Congo red tests were less reliable. Except patients with Roux-en-Y anastomosis, patients with negative or weakly positive CR tests did not have recurrent ulcers or other symptoms attributable to acid hypersecretion. The CR test was easier to perform and preferred by the patients. We conclude that both tests provide valuable clinical information and that both tests should be available in the evaluation of postgastrectomy patients.

Involvement of the gastric vagal nerve in the suppression of pulsatile luteinizing hormone release during acute fasting in rats.

Acute fasting has been shown to impair gonadotropin secretion in an estrogen-dependent manner in rats. The present study examined whether the vagus nerves have some role in the suppression of pulsatile LH release after 48-h fasting in ovariectomized estradiol-treated rats by performing complete subdiaphragmatic cutting of the nerves or selective sectioning of its branches (gastric, hepatic, or celiac) after the first hour of a 3-h blood sampling period. Vagotomy, alone, did not cause any changes in LH release in the unfasted animals. However, complete and gastric vagotomies restored pulsatile LH release that was suppressed before the nerves were cut in fasted animals. Neither hepatic nor celiac vagotomy restored pulsatile LH release, which remained suppressed throughout the sampling period in fasted animals. These results suggest that some mechanism involving the afferent vagal nerves, particularly the gastric vagus, has a major role in the suppression of pulsatile LH release during acute fasting in ovariectomized estradiol-primed rats.

Do perforated duodenal ulcers need an aciddecreasing surgical procedure now that omeprazole is available?

If a chronic duodenal ulcer perforates, the choice of operation will depend on the patient's condition. Preoperative shock, concurrent medical diseases, severe generalized peritonitis, or the presence of an intra-abdominal abscess are contraindications to a definitive ulcer operation; hence, simple closure or omental patch closure is performed. Omeprazole can then be used to heal the ulcer in the early postoperative period, with long-term H2-blocker therapy to follow. The patient without a contraindication to a definitive operation should have a proximal gastric vagotomy in addition to an omental patch closure of the perforation. The addition of this procedure does not change the operative mortality rate in properly selected patients, does not cause the gastrointestinal sequelae associated with truncal vagotomy and pyloroplasty or resection, and has a low rate of recurrent ulcer in experienced hands. The presence of a synchronous posterior "kissing" duodenal ulcer would prompt some to choose a vagotomy and pyloroplasty in preference to a proximal gastric vagotomy. The appropriate operation to perform after perforation of an acute duodenal ulcer in a patient with any of the contraindications listed above is simple closure or omental patch closure. In the stable nonseptic patient, the choice is not as clear. Boey and associates noted cumulative recurrent ulcer rates of 37% and 31% at 3 years in separate studies in which omental patch closure was used for perforated acute duodenal ulcers. This may reflect the asymptomatic nature of chronic duodenal ulcers in some patients prior to perforation, the failure of the surgeon to recognize the extent of periduodenal scarring at operation, or differences in the length of postperforation follow-up in series reporting perforations of acute or chronic ulcers. Jordan has suggested that all stable patients with perforated duodenal ulcers should undergo a proximal gastric vagotomy in addition to omental patch closure. In his hands, the addition of proximal gastric vagotomy has an operative mortality rate of 0 to 1%, a recurrent ulcer rate of 3% to 5%, and no adverse postoperative sequelae. He has noted that "this operation gives protection from further ulcer disease to those who need it and will produce no harm to the unidentifiable patients that might not have benefited from definitive surgery." Boey and Wong suggested that omental patch closure is indicated for "acute ulcers associated with drug ingestion or acute stress" in addition to those that occur in patients who are considered to be poor risk, while proximal gastric vagotomy should be added in the remaining patients with perforations of acute ulcers.(ABSTRACT TRUNCATED AT 400 WORDS)

Current Surgical Management Of Duodenal Ulcers

The optimal treatment of duodenal ulcer disease today requires familiarity with a variety of operative approaches. Experience and judgment are needed to select the best procedure for the individual patient presenting with a specific ulcer complication. Improved medical therapy has relegated surgery largely to the role of emergency life-saving intervention. Nonetheless, the goal of surgery remains cure of the ulcer diathesis with avoidance of postoperative side effects. Toward this end, proximal gastric vagotomy has proved itself to be the operation of choice, not only for intractable pain, but also for perforation and perhaps for bleeding in selected good-risk patients. Its efficacy in the treatment of obstructing duodenal ulcer has not been demonstrated. Modifications of proximal gastric vagotomy, including the use of laparoscopic techniques, are currently being evaluated in patients with intractable duodenal ulcer pain.

Influence of vagotomy on bicarbonate secretion in the rat proximal duodenum.

The influence of vagotomy on bicarbonate secretion in the proximal duodenum was assessed in rats receiving truncal, hepatoduodenal and gastric vagotomy. Two weeks after vagotomy, animals fasted for 24 hr were subjected to laparotomy under urethane anesthesia. A proximal duodenal loop excluding the outlet of the common bile duct was prepared as part of an airtight extracorporeal perfusion circuit. The circuit was filled with a bathing solution at pH 4.5 and which was perfused at a rate of 10 ml/min at a constant temperature of 37 degrees C. The pH and CO2 tension of the bathing solution were determined using microelectrodes, and bicarbonate secretion was calculated from the pH and CO2 tension data by the Henderson-Hasselbalch equation. The bicarbonate secretion at the first portion of the duodenum over a 60-min period was significantly higher in the truncal and hepatoduodenal vagotomy groups than in the control group. However, there was no significant difference between the gastric vagotomy and control groups. Furthermore, no significant difference was noted between the truncal and hepatoduodenal vagotomy groups. Since bicarbonate secretion was increased by hepatoduodenal vagotomy, the hepatoduodenal branch of the vagus nerve appeared to inhibit bicarbonate secretion at the first portion of the duodenum.

The endoscopic Congo red test during proximal gastric vagotomy: an essential procedure.

A previously described method for evaluating the completeness of proximal gastric vagotomy (PGV), the intraoperative endoscopic Congo red test (ECRT), may allow for a more complete parietal cell denervation and thus result in a lower long-term incidence of postvagotomy ulceration. Of 20 patients undergoing PGV, 12 (60%) required further gastric denervation after intraoperative ECRT of the following sites: right gastroepiploic nerve (7), the nerve of Grassi (4), and the lesser curvature (3). Confirmation of completeness of PGV by the ECRT was easily performed and ensured intraoperative quality control. The routine performance of intraoperative ECRT during PGV may ultimately decrease the incidence of subsequent recurrent ulceration.

Gastric Emptying After Fundoplication With and Without Proximal Gastric Vagotomy

Fifty-four patients having antireflux surgery (20 fundoplication alone [group 1] and 34 fundoplication with proximal gastric vagotomy [group 2], had their gastric emptying assessed preoperatively and postoperatively. At 3 years after operation, in group 1, the emptying of a solid meal was significantly accelerated. In contrast, no such acceleration in solid emptying was observed in group 2. Liquid emptying was significantly accelerated in both groups of patients postoperatively. No consistent relationship was found between symptomatic outcome and gastric emptying in either group of patients. We conclude that proximal vagotomy interferes with reflex pathways that are involved in the acceleration of solid gastric emptying after fundoplication.

The Demise of General Surgery: Déjà Vu

The anticipated demise of general surgery is again premature and unwarranted. Rising from the ashes that many have predicted, general surgery has been resurrected despite these false prophets. The abominable surgeons live on! Laparoscopic cholecystectomy, a consumer-driven procedure, has engulfed our profession and challenged our creativity while increasing the visibility and viability of general surgery. Surgeons traditionally operating in two dimensions have found improved agility and opportunities in three dimensions. Surgeons now await improved technology to safely carry out this explosion of new ideas. Success with this single procedure has opened up a dynamic, rapidly evolving era for general surgery. In addition to biliary tract surgery, our colleagues throughout the world are performing proximal gastric vagotomy, herniorrhaphy, Nissen fundoplication, appendectomy, Heller myotomy, and bowel resection. Many predict this to be a delightful beginning. For the senior (mature) members of our profession, this may sound like Star Wars, but it has

Surgical Treatment of Peptic Ulcer Disease

Elective surgery for peptic ulcer disease has diminished significantly over the past 15 years. However, emergency surgery has not shown a decline. Some series have even reported an increase in hospitalizations and operations for hemorrhage. The appropriate surgical procedure for peptic ulcer disease must be tailored to the specific needs of the individual patient. During emergency operations for hemorrhage from duodenal ulcer, we recommend suture ligature of the bleeding vessel and vagotomy-pyloroplasty for high-risk patients, or vagotomy-antrectomy for the lower-risk patient. Bleeding gastric ulcers should be resected, if possible. For massive hemorrhage from stress ulceration requiring surgery, near-total or total gastrectomy should be performed. Perforated duodenal ulcers are best managed by closure and a definitive ulcer operation, such as vagotomy-pyloroplasty. Perforated gastric ulcers are best excised but may be simply closed if conditions do not favor resection. In these situations, biopsy should be performed. We recommend truncal vagotomy-antrectomy for patients presenting with obstruction. Vagotomy (truncal or proximal gastric) with drainage is an acceptable alternative in this situation. For patients with intractable ulcer disease or for those who are noncompliant, proximal gastric vagotomy is the preferred operation. However, other operations may need to be considered, depending on the specific situation. Recurrent ulceration needs appropriate work-up to determine the possible cause. Although patients with ulcer recurrence initially may be placed on medical treatment, about 50% will require reoperation. The most effective procedure for peptic ulcer disease is truncal vagotomy-antrectomy, which has a recurrence rate of less than 1%. The procedure with the least morbidity and the fewest undesirable side effects is proximal gastric vagotomy. Ulcer recurrence after proximal gastric vagotomy or truncal vagotomy-pyloroplasty is in the range of 10% to 15%.