Abdominal lymphangiomas in adults.

Abdominal lymphangiomas are rare benign cystic tumors that can become locally invasive and often require resection. They arise in all ages and have a variable presentation. We performed a retrospective review of a single institution surgical experience with this lesion in adults. The pathology prospective database was reviewed to identify patients with surgically resected abdominal lymphangiomas from January 1986 to May 2004. Retrospective review and follow-up was performed for each patient. The six patients with abdominal lymphangiomas ranged in age from 38 to 66 years. They presented with a variety of signs and symptoms. All underwent CT scan that demonstrated a cystic lesion, but in only one third was the diagnosis made preoperatively. Tumors were located in the retroperitoneum, small bowel mesentery, liver, and pancreas. Five of the six tumors were completely resected. Two of the six required resection of adjacent or involved organs. Follow-up ranged between 6 months and 18 years. All had symptomatic relief after resection, and no patient showed evidence of recurrence in this time period. Abdominal lymphangiomas are rare. The correct diagnosis often remains elusive until tissue is obtained. The treatment of choice is complete surgical resection. When completely resected, these lesions seem not to recur, and the overall prognosis is excellent.

General anesthesia improves fetal cerebral oxygenation without evidence of subsequent neuronal injury.

Anesthetic exposure during pregnancy is viewed as a relatively routine medical practice. However, recent rodent studies have suggested that common anesthetic agents can damage the developing brain. Here we assessed this claim in a higher order species by exposing previously instrumented near-term pregnant sheep at gestational day 122 (+/-1) to a combination of midazolam, sodium thiopental, and isoflurane at clinically relevant doses and means of anesthetic delivery (i.e., active ventilation). Four hours of maternal general anesthesia produced an initial increase in fetal systemic oxygenation and a sustained increase in fetal cerebral oxygenation, as determined by in utero near-infrared spectroscopy. Postexposure monitoring failed to identify changes in physiologic status that could be injurious to the fetal brain. Finally, through the histologic assessment of noninstrumented sheep at the same gestational time point, we found no evidence for a direct fetal neuro-toxic effect of our triple-drug regimen. Collectively, these results appear to corroborate the presumed safety of inhalational anesthetic use during pregnancy.

Predicting resectability of periampullary cancer with three-dimensional computed tomography.

The radiographic assessment of extent of tumor burden and local vascular invasion appears to be enhanced with three-dimensional computed tomography (3D-CT). The purpose of this study was to evaluate the impact of preoperative 3D-CT in determining the resectability of patients with periampullary tumors. Intraoperative findings from exploratory laparotomy were gathered prospectively from 140 patients who were thought to have periampullary tumors and were deemed resectable after undergoing preoperative 3D-CT imaging. CT findings were compared to intraoperative findings, and the accuracy of 3D-CT in predicting tumor resectability and, ultimately, the likelihood of obtaining a margin-negative resection were assessed. Of the 140 patients who were thought to have resectable periampullary tumors after preoperative 3D-CT, 115 (82%) were subsequently determined to have periampullary cancer. The remaining 25 patients had benign disease. Among the patients with periampullary cancer, the extent of local tumor burden involving the pancreas and peripancreatic tissues was accurately depicted by 3D-CT in 93% of the patients. 3D-CT was 95% accurate in determining cancer invasion of the superior mesenteric vessels. Preoperative 3D-CT accurately predicted periampullary cancer resectability and a margin-negative resection in 98% and 86% of patients, respectively. For patients with pancreatic adenocarcinoma (n=85), preoperative 3D-CT resulted in a resectability rate and a margin-negative resection rate of 79% and 73%, respectively. The ability of 3D-CT to predict a margin-negative resection for periampullary cancer, including pancreatic adenocarcinoma, relies on its enhanced assessment of the extent of local tumor burden and involvement of the mesenteric vascular anatomy.

Incidence and outcome of biliary strictures after pancreaticoduodenectomy.

OBJECTIVE: This single-institution review examined the incidence of biliary stricture formation after pancreaticoduodenectomy (PD) for benign and malignant periampullary disease. BACKGROUND: The incidence and course of stricture of the hepaticojejunostomy have not been documented after PD. METHODS: Between January 1995 and April 2003, 1595 patients underwent PD for periampullary disease (392 benign, 1203 malignant). A retrospective analysis of a prospectively collected database was performed to determine the incidence of biliary stricture after PD. RESULTS: Forty-two of the 1595 patients (2.6%) who underwent PD developed postoperative jaundice secondary to a stricture of the biliary-enteric anastomosis. There was no difference in the incidence of biliary strictures after resection for benign (n = 10, 2.6%) or malignant disease (n = 32, 2.6%). The median time to stricture formation resulting in jaundice was 13 months (range, 1-106 months) and was similar for patients with benign and malignant disease. Preoperative jaundice did not protect against biliary stricture formation. By univariate analysis, biliary strictures were associated with preoperative percutaneous biliary drainage (odds ratio [OR] = 2.11, P = 0.02) and postoperative biliary stenting (OR = 2.11, P = 0.013). Postoperative chemoradiotherapy in patients with malignant disease was not associated with stricture formation. All strictures were initially managed with percutaneous biliary balloon dilatation and stenting, and only 2 patients required redo hepaticojejunostomy. Recurrent neoplastic disease was discovered in only 3 of the 32 patients (9%) with malignant disease. All 3 of these patients had cholangiocarcinoma as their initial diagnosis. CONCLUSIONS: Biliary stricture formation is an infrequent complication after PD and can be managed successfully with percutaneous biliary dilatation and short-term stenting in most patients. The only significant univariate predictors for biliary stricture formation were preoperative and postoperative percutaneous biliary drainage. The development of a biliary stricture in patients who have undergone PD for malignant disease is usually benign and should not be automatically attributed to anastomotic tumor recurrence.

Analysis of the brain bioavailability of peripherally administered magnesium sulfate: A study in humans with acute brain injury undergoing prolonged induced hypermagnesemia.

OBJECTIVE: Based on preclinical investigations, magnesium sulfate (MgSO4) has gained interest as a neuroprotective agent. However, the ability of peripherally administered MgSO4 to penetrate the blood-brain barrier is limited in normal brain. The current study measured the passage of intravenously administered Mg into cerebrospinal fluid in patients with brain injury requiring ventricular drainage. DESIGN: A prospective evaluation of the cerebrospinal fluid total and ionized magnesium concentration, [Mg], during sustained hypermagnesemia was performed. SETTING: Neurosciences intensive care unit at a major teaching institution. PATIENTS: Thirty patients with acute brain injury secondary to subarachnoid hemorrhage, traumatic brain injury, primary intracerebral hemorrhage, subdural hematoma, brain tumor, central nervous system infection, or ischemic stroke were studied. INTERVENTIONS: Patients underwent 24 hrs of induced hypermagnesemia during which total and ionized cerebrospinal fluid [Mg] was measured. Serum [Mg] was adjusted to 2.1-2.5 mmol/L. Cerebrospinal fluid [Mg] was measured at baseline, at 12 and 24 hrs after onset of infusion, and at 12 hrs following infusion termination. MEASUREMENTS AND MAIN RESULTS: At baseline, total (1.25 +/- 0.14 mmol/L) and ionized (0.80 +/- 0.10 mmol/L) cerebrospinal fluid [Mg] was greater than serum total (0.92 +/- 0.18 mmol/L) and ionized (0.63 +/- 0.07 mmol/L) [Mg] (p < .05). Total (1.43 +/- 0.13 mmol/L) and ionized (0.89 +/- 0.12 mmol/L) cerebrospinal fluid [Mg] was maximally increased by 15% and 11% relative to baseline, respectively, during induced hypermagnesemia (p < .05). CONCLUSIONS: Hypermagnesemia produced only marginal increases in total and ionized cerebrospinal fluid [Mg]. Regulation of cerebrospinal fluid [Mg] is largely maintained following acute brain injury and limits the brain bioavailability of MgSO4.

Maternal insufflation during the second trimester equivalent produces hypercapnia, acidosis, and prolonged hypoxia in fetal sheep.

BACKGROUND: Anecdotal reports suggest that the second trimester is the safest time to conduct a laparoscopic procedure on a pregnant patient, but this supposition has not been tested empirically. METHODS: Previously instrumented preterm sheep (total n = 8) at gestational day 90 (term, 145 days) were anesthetized and then insufflated with carbon dioxide for 60 min at a pressure of 15 mmHg. Cardiovascular parameters were continuously recorded while blood gas status was determined before and at 15-min intervals during and up to 2 h after insufflation. RESULTS: Insufflation produced minimal maternal blood gas or cardiovascular changes except for a significant reduction in uterine blood flow. The decrease in perfusion increased fetal arterial blood partial pressure of carbon dioxide and decreased fetal pH, oxygen saturation, and oxygen content; there was also progressive fetal hypotension and bradycardia. After manually deflating the ewe, uterine blood flow returned to normal, and the fetal partial pressure of carbon dioxide and pH changes resolved within 1 h. However, fetal oxygen saturation and content remained depressed, and fetal cardiovascular status continued to decline during the 2-h postinsufflation monitoring period. CONCLUSION: Previous studies with near-term sheep determined that carbon dioxide pneumoperitoneum produces respiratory acidosis but does not decrease fetal oxygenation. In contrast, the current findings indicate that in the preterm fetus, insufflation-induced hypercapnia and acidosis are accompanied by prolonged fetal hypoxia and cardiovascular depression. This result suggests that additional work should be conducted to confirm the presumed safety of conducting minimally invasive procedures during the second trimester.