A novel triple secured technique for pancreatic reconstruction following pancreaticoduodenectomy for a soft pancreas.

BACKGROUND/AIMS: Soft pancreases are susceptible to developing pancreatic fistula following pancreaticoduodenectomy. To reduce the incidence of pancreatic fistula after pancreaticoduodenectomy in patients with a soft pancreas, we developed a triple secured technique. In this study, we describe the details of this technique and also report on the postoperative outcomes. METHODOLOGY: The triple secured technique employed an ultrasonic dissector for pancreatic transection with skeletonizing and ligating of the small pancreatic branch ducts, duct-invagination or duct-to-mucosa anastomosis for main pancreatic duct management, and, finally, four large stitches between the pancreatic stump parenchyma and the jejunal seromuscular layer to prevent minor pancreatic leakage. A total of 28 consecutive patients with a soft pancreas who underwent pancreaticoduodenectomy using our technique were included in this study. RESULTS: Postopetrative complications occurred in 16 patients. Grade B pancreatic fistula developed in 6 patients. However, no grade C pancreatic fistula occurred in this series. Neither any reoperation nor in-hospital mortality was observed in this series. CONCLUSIONS: Our triple secured technique after pancreaticoduodenectomy was feasible and safe, with an acceptable rate of grade B pancreatic fistula and no grade C pancreatic fistula for patients with a soft pancreas.

Local steroid injection into the artificial ulcer created by endoscopic submucosal dissection for gastric cancer: prevention of gastric deformity.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) of large gastric lesions results in an extensive artificial ulcer that can lead to marked gastric deformity. The aim of the current study was to evaluate therapeutic efficacy in the prevention of gastric deformity of local triamcinolone acetonide (TCA) injection into the extensive artificial ulcer following ESD. PATIENTS AND METHODS: A total of 45 patients who were diagnosed with early gastric cancer were enrolled. Patients were randomly assigned by the sealed-envelope randomization method to either local TCA injections (n = 21) or sham-control (n = 20) groups. Two clips were placed at the two maximum outer edges of the artificial ulcer after the lesion had been resected (Day 0). Local TCA injections were performed on postoperative Day 5 and Day 12. The distance between the two clips was measured by endoscopic measuring forceps on Days 5, 12, 30, and 60. Granulation formation and gastric deformity were evaluated by visual analog scale (VAS) on Days 30 and 60. RESULTS: Local TCA injection did not alter clip-to-clip distance on postoperative Day 60, and formation of flat granulation tissue over the ulcer was followed by regenerative mucosa without any gastric deformity. The sham-control group showed significant shortening of clip-to-clip distance compared with the local steroid-injected group and protruded forms of granulation tissue with mucosal convergence. Histological evaluation revealed prominent growth of neovessels, swelling, and marked increases in endothelial cells in the local steroid-injected group compared with the sham-control group. CONCLUSIONS: Local steroid injection into the floor of a post-ESD artificial ulcer promotes the formation of granulation tissue at an early stage of the healing process leading to regeneration of gastric mucosa without mucosal convergence or gastric deformity.

Establishment of pure NOTES procedure using a conventional flexible endoscope: review of six cases of gastric gastrointestinal stromal tumors.

An increasing number of reports have recently been published on hybrid natural orifice transluminal endoscopic surgery (NOTES). These reports do not address how to complete an operation with a flexible endoscope alone (pure NOTES), but rather how to combine use of an endoscope and a laparoscope. Surgical procedures using flexible and rigid endoscopes have been developed using different processes and concepts. Recognizing this conceptual difference, we conducted a study to address how to establish a pure NOTES procedure. Six patients with gastric gastrointestinal stromal tumors (GISTs) underwent hybrid NOTES. Each case was retrospectively reviewed to determine the appropriateness of the treatment and the usefulness of the endoscopic submucosal dissection (ESD) method, double-scope method, spaced perforation method, duodenal balloon occlusion method, and loop clip technique. The development of operative procedures that take advantage of the characteristics of flexible endoscopes, even with conventional flexible endoscopic devices and conventional endoscopes alone, may contribute to the realization of pure NOTES.

The use of gastric electrical signals for algorithm for automatic eating detection in dogs.

Food ingestion increases fundic impedance (FI) and reduces antral slow wave rate (SWR). Our aim was to determine if such changes can be integrated into an algorithm for automatic eating detection (AED). When incorporated in implantable medical devices, AED can time treatment to food intake without need for patient input. Four dogs were implanted with fundic and antral electrodes, connected to an implantable recording device. Changes in FI and SWR induced by fixed meals of different weights were determined, and were used to build an AED algorithm. Its performance was then tested on the same animals given an ad libitum access to food. The effects of gastric balloon distension and nitroglycerin on SWR and FI were also tested. Fixed meals reduced SWR in a weight-dependent manner, R(2) = 0.936, P < 0.05 baseline compared to 50, 100, 200 and 400 g. Meals increased FI above baseline in a weight-dependent manner; R(2) = 0.994, P < 0.05 baseline compared to 200 and 400 g. During ad libitum intake, the AED algorithm detected 86% of all meals > or =15 g. Gastric distension reduced SWR and increased FI. Nitroglycerin reduced SWR. AED, using changes in FI and gastric SWR is feasible. Changes in FI and SWR are induced primarily by the presence of food in the stomach.

Performance differences in laparoscopic surgical skills between true high-definition and three-chip CCD video systems.

BACKGROUND: Laparoscopic surgery requires surgeons to rely on visual clues for discrimination among differing tissues and for depth of field on a two-dimensional screen. High definition (HD) provides a superior image. If there is a measurable advantage with HD television (TV), the increase in the cost of the technology would be justified. METHODS: A digital three-chip CCD camera with a standard monitor (SD system) and a true HD camera (1,080 pixels) with a 16:9-ratio HD monitor (HD system) were compared in clinical and laboratory settings. Three experiments were performed: (1) subjective visual evaluation of the HD and SD systems during actual surgical cases, (2) subjective visual evaluation in a controlled laboratory surgical setting with simultaneous parallel recording, and (3) three laparoscopic surgical task evaluations in a laboratory setting, namely, task A (metric analysis of participants on the surgical simulator), task B (simple eye-hand coordination performance), and task C (knot tying). RESULTS: All 53 participants subjectively evaluated HD as superior to SD in the laboratory setting and during actual surgery. In task B, there was no significant difference between SD and HD (dominant hand: p = 0.19; nondominant hand: p = 0.07). In task C, the knot-tying time was significantly less when performed with HD (mean, 173 +/- 84 s vs 214 +/- 107 s; p = 0.003). Most importantly, subjects with less skill (more documented time required in the basic module on a surgical simulator) improved significantly in the knot-tying task with the HD system (R = 0.631; p = 0.005). CONCLUSION: All the participants preferred HD to SD. High definition significantly improved laparoscopic knot tying, which requires precise depth perception, proving that HD is more than just a pretty picture.

Seeing is believing: the importance of video laryngoscopy in teaching and in managing the difficult airway.

Of the several million patients who undergo surgery in North America annually, a large proportion undergo intubation of the trachea. In approximately 90% of these patients, the endotracheal tube is introduced using a traditional laryngoscope with a battery in the handle and a small bulb near the tip of the blade. This bulb provides a limited and often dim view of the glottic structures. In about 10% of cases, the patient is intubated using a flexible fiberoptic intubating scope. The authors have developed a video laryngoscope that preserves the standard blade configuration with a modified handle. A 3-mm image light guide is built into the blade, replacing the bulb. A small TV camera with an incorporated light bundle is inserted into the handle. A wide-angle panoramic view of the upper airway anatomy is displayed on a TV screen, which can be positioned at a convenient working distance. The use of a TV monitor is a well-accepted standard during minimally invasive surgical procedures.

Operating videoscope for microlaryngeal surgery.

For operative laryngoscopy, a laryngoscope is introduced into the anesthetized patient's mouth for exploration of the larynx and vocal cords. To improve the vision, a binocular microscope is positioned between the operator and the laryngoscope. This interferes, to some degree, with the introduction of instruments, particularly if the surgeon is using bimanual manipulation. In the case of lengthy operations, a fatigue or stress factor can be troublesome to the operator. The authors developed a video laryngoscope using standard blades. An angulated telescope attached to a TV camera was introduced in the top portion of the blade. An enlarged image from the anatomy was produced and viewed from a convenient distance. The manipulations are unobstructed, and simultaneous records can be obtained. It is the method of choice for teaching. The operative laryngoscope is less cumbersome and supersedes the microscope for viewing the endolarynx. This new technique was used successfully in 532 cases.

Changes in arterial and portal perfusion in embolized and nonembolized hepatic lobes after portal vein embolization evaluated by helical computed tomography.

We evaluated the changes in hepatic arterial and portal perfusion in nonembolized as well as in embolized lobes after portal venous branch embolization (PVE) with dynamic helical computed tomography (CT). Six patients with hepatic malignancies, who underwent PVE prior to a subsequent hepatectomy, were the subjects of this study. We performed CT examinations before PVE and 2 weeks after PVE to make a volumetric analysis. At the same time, we performed single-location dynamic sequences after the injection of a 50-ml bolus of contrast medium, and we then created time-density curves from circular regions of interest drawn over the aorta, parenchyma of the right and left lobe of the liver, and spleen. We calculated the arterial perfusion index (ml/min per ml of tissue) and the portal perfusion index by dividing the maximum rate of enhancement of the liver before and after the splenic peak by the peak aortic enhancement. We then calculated the arterial and portal flows (ml/min) from the perfusion index and values of CT volumetry. In the right lobe, where the portal flow was occluded, the arterial perfusion index and flow increased significantly after PVE. In contrast, the arterial perfusion index and flow both decreased in the left lobe after PVE in a reverse response to the increase in the portal perfusion index and flow. The total arterial flow of the liver thus seemed to slightly increase; however, the change was not significant. By performing PVE an increased arterial perfusion was induced in the embolized lobe, with a concomitant decrease in arterial perfusion in the nonembolized lobe.

Acute responses of renal nerve activity to microgravity induced by free drop in anesthetized rats.

To examine acute cardiovascular and autonomic responses to microgravity (microG), arterial pressure (AP), aortic flow velocity (AFV), central venous pressure (CVP), and renal nerve activity (RNA) were measured in anesthetized rats during 4.5 s of microG produced by free drop. A smooth and immediate reduction in gravity occurred during free drop, microG being achieved 100 ms after the start of the drop. Acute microG elicited an immediate and striking, but transient, decrease in RNA with no significant change in AP and AFV, but a significant decrease in CVP. The decrease in RNA lasted 2 s, then RNA recovered to the control level despite the G value remaining at < 0.001 for 4.5 s. The RNA decrease was attenuated or completely abolished by sinoaortic denervation, vagotomy, or sinoaortic denervation plus vagotomy. These results suggest that acute microG conditions stimulate sinoaortic and cardiopulmonary mechanoreceptors and suppress RNA.

Role of the vestibular system in sudden shutdown of renal sympathetic nerve activity during microgravity in rats.

The purpose of this study was to examine the effect of microgravity (muG) on renal sympathetic nerve activity (RNA) in rats. Additionally, we estimated the participation of the vestibular system in the response of RNA to muG. Eight normal Sprague-Dawley (SD) rats and five chemically and bilaterally labyrinthectomied SD rats were used to measure RNA during free-drop examination (4.5-s duration of muG); arterial pressure (AP) and aortic flow velocity (AFV) were additionally monitored. Although AFV showed no particular change, AP tended to decrease during muG in the later phase. Prior to this AP fall-off, RNA was immediately and markedly attenuated by muG. This attenuation was transient and RNA returned to 1G level within the mu;muG condition. Interestingly, this phenomenon remained even in labyrinthectomied rats. In conclusion, cephalad shift of the body fluid by loading of muG may cause cardiopulmonary low-pressure receptor activation and consequent RNA attenuation, but the participation of the vestibulosympathetic reflex in this phenomenon is not obvious.

Functional evidence for involvement of bumetanide-sensitive Na+K+2CI- cotransport in the hepatoportal Na+ receptor of the Sprague-Dawley rat.

To investigate mechanisms involved in hepatoportal Na+ sensing, responses of hepatic afferent nerve activity (HANA) to intraportal hypertonic NaCl injection were measured before, and after, intraportal infusion of inhibitors of Na+ transport systems. HANA increased in response to the intraportal injection of 0.75 M NaCl in a dose-dependent manner. The HANA response was not affected by amiloride or 4-acetamido-4'-isothiocyanato-stilbene-2,2'-disulfonic acid (SITS), but was suppressed in a dose-dependent manner by intraportal infusion of ouabain, furosemide, or bumetanide. These results indicate that the hepatoportal Na+ receptor senses the Na+ concentration via the bumetanide-sensitive Na+K+2Cl- cotransporter.

Mechanism of biphasic response of renal nerve activity during acute cardiac tamponade in conscious rabbits.

Renal sympathetic nerve activity (RSNA) responses to acute cardiac tamponade were studied in conscious rabbits with all reflexes intact (Int) or after either surgical sinoaortic denervation (SAD) or administration of intrapericardial procaine (ip-Pro) or intravenous procaine (iv-Pro). In Int rabbits, the mean arterial pressure (MAP) remained relatively constant until the pericardial volume reached 7. 7 ml, whereas the RSNA increased to 226% [compensated cardiac tamponade (CCT)], then, at a pericardial volume of 9.3 ml, the MAP fell sharply and RSNA decreased to 34% [decompensated cardiac tamponade (DCT)]; 1 min after cessation of pericardial infusion, an intravenous injection of naloxone resulted in increases in both MAP and RSNA. In SAD rabbits, RSNA did not alter throughout CCT and DCT, but increased on injection of naloxone. In ip-Pro rabbits, RSNA increased during CCT but did not decrease during DCT, whereas, in iv-Pro rabbits, the RSNA response was similar to that in Int rabbits. These results indicate that RSNA responses to cardiac tamponade are biphasic, with an increase during CCT and a decrease during DCT. Sinoaortic baroreceptors are involved in mediating the increase in RSNA, whereas cardiac receptors may be involved in mediating the decrease in RSNA. An endogenous opioid may be responsible for the decrease in RSNA seen during DCT.

Effects of 7-nitroindazole on renal sympathetic nerve activity during acute cardiac tamponade in conscious rabbits.

To investigate whether nitric oxide (NO) in the central nervous system is involved in the decrease in renal sympathetic nerve activity (RSNA) during acute cardiac tamponade in conscious rabbits, we examined the effect of 7-nitroindazole (7-NI), a selective inhibitor of neuronal nitric oxide synthase in vivo, on RSNA during acute cardiac tamponade in chronically installed conscious rabbits. Cardiac tamponade was produced by intrapericardial infusion of physiological saline at 2 ml/30 s. Mean arterial pressure (MAP) remained constant initially but RSNA increased to 218+/-24% when we started injection of physiological saline into the pericardial space. Concomitantly after MAP fell to 51+/-1 mm Hg by subsequent injection of the saline into the pericardial space, RSNA decreased to 45+/-6%. If 7-NI (50 mg/kg) was administered intraperitoneally 35 min before the beginning of cardiac tamponade, the decline in RSNA caused by cardiac tamponade was markedly counteracted. Brain nitric oxide synthase (NOS) activity in the cerebral cortex and medulla oblongata, assessed by the conversion of labelled arginine to citrulline, was inhibited by 48% and 44% after the intraperitoneal administration of 7-NI. These results indicate that acute cardiac tamponade elicits a biphasic effect on RSNA, which rises during non-hypotensive period and then falls during hypotension in conscious rabbits. The decrease in RSNA was abolished by treatment with 7-NI, suggesting that the abrupt decrease in RSNA during hypotension induced by acute cardiac tamponade is mediated by NO in the central nervous system.

Role of the liver in long-term control of drinking behavior, Na+ balance, and arterial pressure in Dahl rats.

The role of postabsorptive mechanisms in long-term control of drinking behavior, Na+ balance, and arterial pressure was examined in Dahl salt-sensitive (DS) and salt-resistant (DR) rats. NaCl (0.15 M) was infused (0.5 ml/h) into either the inferior vena cava (IVC) or the portal vein (PV) for 7 days, and then 1.5 M NaCl was infused for 10 days. During 1.5 M infusion, the IVC group retained more Na+ than the PV group. Furthermore, in DS rats, mean arterial pressure was higher in the IVC group than in the PV group. Regardless of the strain and infusion route, 1.5 M infusion had no effect on volume of daily saline consumption. However, when the data for light and dark periods were analyzed separately, dark period saline consumption in the PV group was decreased by 1.5 M infusion but was not changed in the IVC group. These results indicate that, in Dahl rats, the postabsorptive mechanism plays a significant role in controlling long-term saline drinking behavior and Na+ balance and has a significant role in controlling arterial pressure in DS, but not DR, rats.

Effects of left intraatrial infusion of prostaglandin E1 after open-heart surgery.

The hemodynamic effects of a left intraatrial infusion of prostaglandin E1 (PGE1) given to ten patients after open-heart surgery (LA group), were compared with those following no treatment in a control group of ten patients, and to those following a right intraatrial infusion given to another ten patients (RA group). PGE1 was infused at a rate of 0.03 microgram/kg/min in the RA group and at 0.003 microgram/kg/min in the LA group, and hemodynamics were measured immediately after surgery, then 3, 6, and 12 h after the PGE1 infusion was commenced. The heart rate, right atrial pressure, left atrial pressure, and mean pulmonary arterial pressure remained almost unchanged in all three groups; however, the mean radial arterial pressure and systemic vascular resistance index decreased, and the cardiac index increased in the RA and LA groups. The pulmonary vascular resistance index decreased only in the LA group. Thus, a much smaller dose of PGE1, being one-tenth of that used for the right atrial infusion, administered directly into the left atrium yielded almost the same hemodynamic effects as the larger dose infused into the right atrium. Furthermore, this method of infusing PGE1 is safe, efficacious, and cost-efficient.

Effects of brain natriuretic peptide and C-type natriuretic peptide infusion on urine flow and jejunal absorption in anesthetized dogs.

Effects of brain natriuretic peptide (BNP) or C-type natriuretic peptide (CNP) on urinary excretion and jejunal absorption of fluid and electrolytes were examined in anesthetized dogs. Intravenous infusion of BNP increased urinary fluid and electrolyte excretion and decreased jejunal fluid and electrolyte absorption. CNP had a similar effect on jejunal absorption as BNP. However, CNP had no significant effect on renal fluid or electrolyte excretion. These results indicate that: 1) BNP is a powerful natriuretic peptide comparable to ANP and; 2) CNP may also contribute to the regulation of body fluid homeostasis by way of inhibiting net jejunal fluid and electrolyte absorption.

Effects of portal infusion of hypertonic solution on jejunal electrolyte transport in anesthetized dogs.

Jejunal electrolyte absorption was measured in the jejunal loops of anesthetized dogs during infusions of hypertonic solutions via the portal vein. The net Na absorption was not influenced by the 9% NaCl infusion into the inferior vena cava, although it was significantly attenuated by the portal 9% NaCl infusion. This effect may not be due to the osmotic stimulus, since the portal 50% glucose or 6.5% LiCl infusion had no significant influence on the net Na absorption. To determine the mechanism of the decrease in the net Na absorption during the portal hypertonic NaCl infusion, the net Na absorption was measured after the section of anterior and posterior hepatic nerves (SAPH) or intravenous atropine injection. Both SAPH and the intravenous atropine injection completely blocked the effect of the portal 9% NaCl infusion on the net Na absorption. These results indicate that 1) net Na absorption in dog jejunum is depressed by the hypertonic NaCl infusion via the portal vein; 2) the effect is NaCl specific and may not be due to the osmotic stimulus; and 3) the afferent limbs of this effect are the anterior and posterior hepatic nerves, and the efferent limb of this effect is the vagus nerve. Thus the hepatojejunal reflex may play an important role in the regulation of body fluid homeostasis.