In vivo visualization of pyloric mucosal hypertrophy in infants with hypertrophic pyloric stenosis: is there an etiologic role?

OBJECTIVE: Infantile hypertrophic pyloric stenosis (IHPS) is a common condition which presents in infants at 2-12 weeks of postnatal life, and whose cause remains obscure. Multiple associated abnormalities have been recognized within the external hypertrophied pyloric muscle layer, but the internal component of the pyloric mucosa has received scant attention in the literature to date. Our purpose in this study was to show that pyloric mucosal redundancy is a constant finding in infants with IHPS, to discuss its possible cause, and to explore the hypothesis of a relationship between pyloric mucosal redundancy and the development of IHPS. MATERIALS AND METHODS: We identified 102 consecutive infants with surgically confirmed IHPS and determined the thickness of the pyloric mucosa compared with the thickness of the surrounding hypertrophied muscle. Fifty-one infants who did not have pyloric stenosis served as controls. RESULTS: Mean mucosal thickness in patients with IHPS approximated mean muscle thickness, with a ratio of 0.89. In infants with IHPS, the pyloric mucosa constitutes approximately one third of the cross-sectional diameter of the pyloric mass and fills and obstructs the pyloric canal. CONCLUSION: Mucosal redundancy is a constant associated finding in IHPS. Although the origin of the redundancy and a cause-and-effect relationship are difficult to establish, our findings support the hypothesis that hypergastrinemia may be implicated in the pathogenesis of IHPS, and suggest that mucosal thickening could be implicated as one of the initiating factors in its development.

Laparoscopic versus open splenectomy in the pediatric population: a contemporary single-center experience.

The purpose of this study was to compare a recent contemporaneous experience between laparoscopic (LS) and open (OS) splenectomy in children. All splenectomy cases between 1994 and 1999 at our institution were reviewed. The study included open and laparoscopic cases performed according to surgeon preference. Emergency splenectomies for trauma were excluded. The patient record was reviewed for the diagnosis, indications, postoperative length of stay, operative technique, postoperative complications, blood loss/blood transfusion, total amount of parenteral narcotics, and time to resumption of oral intake. Chi-square and t tests were used to compare measured differences for statistical significance. Between May 1994 and December 1999, 52 splenectomies were performed at Vanderbilt Children's Hospital. Of these, 45 were elective operations with 29 open and 16 laparoscopic procedures. During four OS and five LS operations a concomitant cholecystectomy was performed. The median patient age was 9.2 years (range 0.5 to 17.3). There was no statistical difference between the two groups in terms of age, weight, American Society of Anesthesiologists class, or estimated blood loss. There were no immediate postoperative complications in either group. There were no conversions from LS to OS. The mean duration of surgery was 264 minutes (LS) versus 169 minutes (OS) (P < 0.05). The average time to first oral intake was shorter in patients undergoing LS (1.1 vs 1.6 days, P < 0.05) and the mean postoperative length of stay was also shorter in the LS group (1.3 vs 3.1 days, P < 0.05). The use of postoperative intravenous narcotics (in morphine-equivalent doses) was significantly less in LS patients than in OS patients (7.5 mg or 0.15 mg/kg vs 46.9 mg or 1.5 mg/kg, P < 0.001), as was the need for PCA pump analgesia (90% in the OS group vs 25% in LS group, P < 0.01). Overall the average hospital charge (anesthesia fee, narcotics charge, and hospital room charge) was $5400 (range $4240-6250) in the OS group and $4950 (range $4450-6240) in the LS group (P < 0.05). Among the nine patients undergoing splenectomy with cholecystectomy, findings between the OS and LS groups were similar except for one late complication consisting of a diaphragmatic hernia in an LS patient. Both LS and OS with or without a concomitant procedure can be accomplished safely in children. LS appears to result in longer operative times but shorter lengths of stay, earlier first oral intake, and significantly fewer requirements for intravenous narcotics; all of these contribute to a reduction in hospital charges compared with the open operation.

CT of bowel and mesenteric trauma in children.

Although most traumatic abdominal injuries in children are treated with conservative nonsurgical management, traumatic perforation or infarction of the gastrointestinal tract still necessitates surgical management. It is imperative to recognize the often subtle computed tomographic (CT) findings of bowel or mesenteric trauma in children. Pediatric patients with bowel perforation or infarction due to trauma usually demonstrate multiple abnormalities at CT. A specific history of lap belt injury, bicycle handlebar injury, or child abuse with an abdominal injury should heighten suspicion for a bowel injury. CT findings in children with bowel or mesenteric trauma include free intraperitoneal air, free retroperitoneal air, extraluminal oral contrast material, free intraperitoneal fluid, bowel wall defect, bowel wall thickening, mesenteric stranding, fluid at the mesenteric root, focal hematoma, active hemorrhage, and mesenteric pseudoaneurysm. Some findings, such as free intraperitoneal air and focal bowel wall thickening, are associated with a strong likelihood of a bowel injury that requires surgical repair. Other findings, such as free intraperitoneal fluid, mesenteric stranding, fluid at the mesenteric root, and focal hematoma, are less specific for an injury that requires surgical repair. The hypoperfusion complex can usually be differentiated from a traumatic bowel injury; however, in some patients the imaging findings overlap.

The influence of prostaglandin E1 on platelet adherence and injury in preserved rat liver allografts.

We have previously shown that part of the injury sustained by cold-preserved livers on reperfusion is the consequence of platelet adhesion to sinusoidal endothelium. The purpose of the present study was to determine whether prostaglandin E1 (PGE1) can reduce the injury and if so, how to maximize this beneficial effect. Rat livers were cold-preserved in University of Wisconsin solution for 30 hours then subjected to 1-hour warm ischemia after which they were reperfused at 37 degrees C with oxygenated Krebs-Henseleit solution with or without isolated platelets. PGE1 was used to treat the donor liver during harvesting, cold preservation, and reperfusion. In some studies, PGE1 was used to pretreat platelets before exposing them to the liver, and in other studies, both liver and platelets were treated. Pretreatment of platelets with paraformaldehyde, which inactivates them, or ADP, which activates them, was also studied. Treatment of livers with PGE1 significantly decreased preservation injury when livers were reperfused in the absence of platelets. However, when platelets were added to the perfusate, prior treatment of the liver with PGE1 had relatively minor beneficial effects. Pretreatment of platelets alone with PGE1 was also beneficial, but again the effect was small. However, when both liver and platelets were treated with PGE1 there was a highly significant decrease in the extent of liver injury and platelet adhesion. Perfusate transaminase levels were lower, bile flow was improved, and histologically, livers appeared less injured. Pretreatment of platelets with paraformaldehyde produced similar results to pretreatment with PGE1. When platelets were preactivated with adenosine diphosphate, extensive hepatic injury occurred upon reperfusion despite PGE1 treatment of the liver. PGE1 can lessen preservation-reperfusion injury impressively when administered to both liver and platelets but has little effect when platelets have been preactivated.

Role of platelets in hepatic allograft preservation injury in the rat.

Cold preservation of liver allografts injuries hepatic sinusoidal lining cells. This injury is exacerbated on reperfusion, in part because of adhesion of leukocytes. Platelets also adhere to activated endothelial surfaces. In this study we examined the role of platelets in preservation injury. Our specific aim was to determine whether the degree of platelet adhesion on reperfusion of preserved rat livers was related to duration of cold or warm ischemia and whether platelet adhesion resulted in injury to allografts. We also examined the effect of prior activation of platelets on adhesion and injury. Rat livers were preserved at 1 degree C for different time periods in University of Wisconsin solution and then reperfused for 3 hr on the isolated perfused rat liver system with Krebs-Henseleit solution to which unactivated isolated rat platelets were added. Other livers were rewarmed before reperfusion or reperfused with activated platelets. Platelets were lost from the circulation in all studies; the percentage reduction of circulating platelets was dependent on the length of preservation. The initial platelet concentration did not affect the rate of reduction of platelets in the circuit. Rewarming before reperfusion increased platelet adherence, and prior activation also increased adherence. With electron microscopy we determined that platelets adhered in small aggregates to endothelial cells or endothelial cell remnants. Adherent platelets appeared more activated and contained fewer granules than did unperfused platelets. Liver injury as measured by release of transaminases into perfusate was worsened by longer periods of cold preservation and by addition of rewarming to the protocol. The presence of platelets under these circumstances aggravated injury. Prior activation of platelets also increased the extent of injury. These studies show that platelets have an important role in cold preservation-reperfusion injury.

Prediction of the outcome of transplantation in man by platelet adherence in donor liver allografts. Evidence of the importance of prepreservation injury.

We examined platelet adhesion in thirty human donor livers to determine if the degree of platelet adhesion could predict outcome of transplantation. Wedge liver biopsies were taken at the start of the donor operation (biopsy 1) and 1 hr after reperfusion in the recipient (biopsy 2). Biopsies were stained with a monoclonal antibody against platelet glycoprotein Ib and graded for platelet adhesion. Hematoxylin and eosin-stained sections were examined for polymorphonuclear leukocyte adhesion and necrosis. Platelet adhesion was much more frequent and extensive than expected in biopsy 1. Nine of 30 biopsies showed moderate or high-grade platelet adhesion. Thus in this study endothelial cell damage was present in about one-third of donors before the donor operation. The injury was not detectable by routine microscopic or clinical examination or biochemical tests. The degree of platelet adhesion in biopsy 1 predicted development of PMN adhesion and necrosis in biopsy 2 and postoperative transaminase concentrations and prothrombin times in recipients. During preservation and implantation some livers converted from low to either moderate or high grades of platelet adhesion. The grade of platelet adhesion in biopsy 2 predicted postoperative outcome as measured by transaminase and PT levels. Patients whose platelet grade converted to a higher level during preservation and implantation did not do as well as patients who remained at a low adhesion grade. These findings strongly suggest that the degree of platelet adhesion is an important determinant in assessing outcome and may provide a means of measuring the status of liver allografts prior to transplantation.

Laparoscopic versus open cholecystectomy: a matched study.

To determine the efficacy of laparoscopic cholecystectomy (LC) in the treatment of gallstone disease, all patients who underwent elective surgery for cholelithiasis during three consecutive periods (1989, 1990 and 1991) were studied. There were 121 patients in each period. All patients in the first period underwent open cholecystectomy (OC), whereas 70 (58%) patients underwent laparoscopic procedures in the second period (OC-LC). LC was the treatment of choice in the third period. Multiple factors, including sex, age, clinical and biochemical presentation of the disease and modified Apache II score were comparable among the three groups. The authors found significant differences in length of hospitalization (6.4 +/- 4.2 days in the OC group, 3.6 +/- 2.4 days in the OC-LC group and 2.4 +/- 1.7 days in the LC group, p < 0.01 when compared with the OC group) and return to work after surgery (5.8 +/- 2.8 weeks, 2.8 +/- 1.2 weeks and 1.3 +/- 1.8 weeks respectively, p < 0.01 when compared with the OC group). There was no significant difference in postoperative complications among the groups, but complications in the OC patients were more severe. Although operative time increased significantly after the introduction of LC, it returned to the range of OC after 36 procedures. Nine patients (5%) with LC required conversion to OC. Benefits of LC include a shorter hospital stay and a shorter recovery period. There were no deaths, very low morbidity, a substantial decrease in overall cost and a high degree of patient satisfaction with LC.

Multiple intrahepatic cholesterol stones.

The authors report a case of multiple intrahepatic cholesterol stones found in an asymptomatic patient who had undergone cholecystectomy 12 years before. Biochemical abnormalities and radiologic and pathologic findings are noted. The patient underwent liver resection with Roux-en-Y choledochojejunostomy and received ursodeoxycholic acid postoperatively. Recovery was uncomplicated, and the patient was well at 1-year follow-up. Intrahepatic cholesterol lithiasis is rare but can be diagnosed preoperatively. Treatment depends on the presence of complications and the distribution of the stones.

Lymphocyte adherence in the reperfused rat liver: mechanisms and effects.

Leukocyte adhesion may play a central role in the pathogenesis of preservation-reperfusion injury to liver grafts. We previously showed that lymphocyte adhesion to sinusoids is dependent on the length of cold ischemia. In the present study we examined the mechanisms of lymphocyte adherence after harvesting combined with a short and a long preservation time. The effects of lymphocyte adherence on liver function were also examined. Rat livers were stored at 1 degrees C in University of Wisconsin solution for 45 min or 30 hr and then reperfused at 37 degrees C in the isolated perfused rat liver with isogeneic lymphocytes in an asanguineous perfusate. The role of reactive oxygen intermediates was investigated with allopurinol, a vitamin E analog and ascorbate or superoxide dismutase and catalase. For us to determine the role of Kupffer cells, Kupffer cell blockade was produced by gadolinium chloride. Leukotriene B4 effects were examined with the lipooxygenase inhibitor, nordihydroguaiaretic acid. We evaluated the possible presence of mechanical obstruction by studying flow rates and the circulation of red blood cells. We examined the role of adhesion molecules by pretreating lymphocytes with trypsin or neuraminidase and by exposing livers to arabinogalactan. We investigated the effects of lymphocyte adhesion on liver function by comparing perfusate liver enzymes in livers reperfused with and without lymphocytes, with trypsinized lymphocytes and with an increased number of lymphocytes. Allopurinol significantly reduced hypoxanthine degradation, and nordihydroguaiaretic acid inhibited leukotriene B4 release into the perfusate. The ability of gadolinium chloride to inhibit Kupffer cells was shown by colloid carbon uptake. In livers harvested and preserved for 45 min, lymphocytes decreased about 40% during reperfusion. In livers preserved for 30 hr, the reduction was significantly greater (about 80%). Lymphocyte adherence was lessened in livers preserved for 45 min by all three of the reactive oxygen intermediate protectants and by gadolinium chloride. In contrast, neither reactive oxygen intermediate protectants nor gadolinium chloride reduced adherence in livers preserved for 30 hr. Nordihydroguaiaretic acid had no effect in livers preserved for either 45 min or 30 hr. Portal flow in livers preserved for 45 min and 30 hr was similar, suggesting an absence of mechanical obstruction, and this finding was supported by a complete absence of red cell trapping. Trypsinization of lymphocytes and exposure of livers to arabinogalactan significantly lessened lymphocyte adherence in livers preserved for 30 hr but not in those preserved for 45 min.(ABSTRACT TRUNCATED AT 400 WORDS)

Recent results of elective open cholecystectomy in a North American and a European center. Comparison of complications and risk factors.

Results of elective open cholecystectomy in 1252 patients treated in a North American and a European center were examined using a recent standardized classification of complications. Although there were significant differences between centers in population age, rate of concomitant disorders, and numbers of operators, the frequency and severity of complications were comparable. There were no deaths, but 12% and 14% of the patients developed complications in the two centers. About 6% of the patients developed grade I complications. Grade II complications were noted in 6% and 8%, and grade III in 0% and 0.3%. Using univariate and multivariate analysis, individual risk factors for developing complications were found to be different in the two centers. Two preoperative scoring systems, ASA and a simplified APACHE II, were predictive for complications in both centers, but did not account for all risk in these patients. Data from the two centers could not be combined because of significant interaction between risk factors and center. Elective open cholecystectomy is a safe procedure, particularly in terms of highly morbid complications and death. Generalization of risk factors identified in a particular center may be misleading because local conditions may significantly affect risk factors for complications. The data also demonstrate the advantages of a uniform way of reporting surgical complications, which may permit meaningful comparisons among centers.

Rapid donor liver nutritional enhancement in a large animal model.

Organ donors are typically subject to acute hyponutrition that might affect postpreservation liver function. Livers from nutritionally supplemented rats function better after preservation than livers from fasted rats. We have developed a method to glycogenate the liver of large animals in the temporal context of a human donor liver operation and have studied the fate of glycogen stores during preservation. Starved anesthetized pigs were infused with a hexose solution (glucose, fructose or galactose) by way of the superior mesenteric vein for 3 hr. Regular porcine insulin was infused to maintain a hyperglycemic hyperinsulinemic arterial glucose clamp at 12 to 16 mmol/L. Liver biopsy specimens and blood samples were taken before infusion and hourly. At 3 hr the liver was excised, stored for 24 hr at 1 degrees C in University of Wisconsin solution and biopsied. It was then placed at 20 degrees C for 1 hr to simulate the reimplantation stage of transplantation. Glycogen and nucleotide levels were measured, and results were corrected for starch in the University of Wisconsin solution. A 20% glucose infusion produced rapid hepatic glycogenation without side effects. Greater glycogenation was obtained with 20% fructose but at the cost of lactic acidosis and a fall in pH. A combination of 15% glucose and 5% fructose produced intermediary glycogenation without significant side effects. Galactose (20%) was less efficient than glucose alone. The addition of alanine and glutamine (20 mmol/L) did not significantly improve glycogenation. Metabolism of glycogen at 1 degree C did occur. Glycogen content fell 0.15% +/- 0.05% dry weight liver per hour during cold preservation and 5.49% +/- 2.15% per hour during ischemic rewarming.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of intraportal glucose infusion on hepatic glycogen content and degradation, and outcome of liver transplantation.

Recent animal studies suggest that nutritional repletion may improve function of liver allografts, and the authors have found that intraportal glucose infusion in pigs produces rapid and substantial hepatic glycogenation. A controlled prospective randomized study in 32 patients was done to determine glycogen content and degradation in human livers during transplantation, and the effect of intraportal glucose-insulin infusions during the donor operation on these variables and on outcome of transplantation. Peripheral blood glucose concentrations were "clamped" at 14 mmol/L during the glucose-insulin infusion. Liver biopsies were taken at various stages of the procedure. Liver glycogen decreased 2.0 +/- 1.2 g/100 g dry weight liver (mean +/- standard error of the mean) in controls, but increased 6.8 +/- 1.8 g/100 g dry weight in glucose-infused donors. In both groups there was glycogen degradation during periods of cold preservation, anoxic rewarming, and after reperfusion with portal blood. Degradation rates were greater in the glucose-infused group than in controls in all three periods (p less than 0.05). Despite wide variation in postoperative aspartate aminotransferase (AST) levels among recipients in both groups, the difference in peak postoperative AST levels approached significance (p = 0.06). In addition, peak AST levels were closely correlated to anoxic rewarming time in both groups, but the slope of the relationship was much lower (3834 versus 734, p less than 0.01) in the glucose-infused group. Thus at anoxic rewarming times over 90 minutes, glycogenation was protective of liver function. Peak postoperative AST was significantly correlated to glycogen degradation in the cold preservation and rewarming periods in the glucose-infused group only. Intraoperative glucose infusions in humans can reglycogenate the liver, increase glycogen degradation, and improve certain outcome measures in liver transplantation.

A method for sequential excision biopsies of rat liver in an isolated perfused system.

We describe a simple method of performing sequential excision biopsies during liver reperfusion in the isolated perfused rat liver. After hepatectomy, four ligatures (5.0 silk) tied with a slip knot are placed around the pedicles of: (1) the inferior and (2) the superior parts of the caudate lobe, as well as (3) the inferior and (4) the superior parts of the right lateral lobe. At the time of biopsy, the prepared 5.0 silk ties are tightened with sufficient force to occlude the vascular pedicle, preventing leakage of circulating perfusate. The procedure provides four biopsies of more than 350 mg each without alteration of perfusate transaminases and tissue ATP contents. The total tissue removed by this method comprises 20-25% of the whole liver weight.