Inguinal herniorrhaphy: for surgical specialists only?
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Hernia, Inguinal↗
Biomedical subjects
D W Rattner
Publications and source records attributed to D W Rattner.
Optical imaging technology in minimally invasive surgery. Current status and future directions.
Optical engineering and imaging technology have played a major role in the evolving field of minimally invasive surgery (MIS) by making it possible to visualize the manipulation of tissue at remote internal sites. We assess and review the optical imaging technology used during a variety of MIS procedures from an engineering perspective. The field of MIS is evolving rapidly. Optic-based technologies have the potential to further improve diagnostic capabilities of MIS. Optical imaging technologies and instrument designs are discussed in relation to their current and future use in MIS procedures. Technical limitations in imaging technology are described, along with potential solutions. We review the current status and future role of optical imaging technology in MIS. In the future, synergistic benefits from engineering, imaging technology, and MIS are likely to improve diagnostic ability and patient care.
Equipment Design↗
Future directions in innovative minimally invasive surgery.
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Forecasting↗
Introduction of appendiceal CT: impact on negative appendectomy and appendiceal perforation rates.
UNLABELLED: OBJECTIVE To evaluate the impact of appendiceal computed tomography (CT) availability on negative appendectomy and appendiceal perforation rates. SUMMARY BACKGROUND DATA: Appendiceal CT is 98% accurate. However, its impact on negative appendectomy and appendiceal perforation rates has not been reported. METHODS: The authors reviewed the medical records of 493 consecutive patients who underwent appendectomy between 1992 and 1995, 209 consecutive patients who underwent appendectomy in 1997 (59% of whom had appendiceal CT), and 206 patients who underwent appendiceal CT in 1997 without subsequent appendectomy. RESULTS: Before appendiceal CT, 98/493 patients (20%) taken to surgery had a normal appendix. After CT availability, 15/209 patients (7%) taken to surgery had a normal appendix; 7 patients did not have CT, 5 patients had surgery despite a negative CT, and 3 patients had a false-positive CT. Negative appendectomy rates were lowered overall (20% to 7%), in men (11% to 5%), in women (35% to 11%), in boys (10% to 5%), and in girls (18% to 12%). Appendiceal perforation rates dropped from 22% to 14% after CT availability. CT excluded appendicitis in 206 patients in 1997 who avoided appendectomy and identified alternative diagnoses in 105 of these patients (51%). CONCLUSION: The availability of appendiceal CT coincided with a drop in the negative appendectomy rate from 20% to 7% in all patients, and to only 3% in patients with a positive CT. Perforation rates decreased from 22% to 14%. Appendiceal CT can be advocated in nearly all female and many male patients.
Adolescent↗
Cystic pancreatic neoplasms.
Cystic pancreatic neoplasms comprise a heterogeneous group of pathologic entities. Mucinous cystic tumors and serous cystadenomas account for more than 75% of reported cases. While serous cystadenomas are almost uniformly benign, mucinous cystic tumors all have malignant potential and must be treated as such. While both clinical and biochemical features can distinguish among the various cystic pancreatic lesions, surgical resection is often required for both definitive diagnosis and treatment. When surgery is performed, benign lesions should be treated with pancreatic parenchymal sparing procedures if anatomy permits. Standard surgical oncologic principles should be employed when treating indeterminate or malignant lesions.
Cystadenocarcinoma, Mucinous↗
Beyond the laparoscope: minimally invasive surgery in the new millennium.
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Abdominal Neoplasms↗
Middle segment pancreatectomy: a novel technique for conserving pancreatic tissue.
Pancreatoduodenectomy and extended distal pancreatectomy for benign tumors in the pancreatic neck and body incur a notable waste of normal tissue and unnecessary risk of both diabetes mellitus and splenic loss. We describe the technique of a limited resection of the middle portion of the pancreas, termed middle segment pancreatectomy, and report our results in 12 patients. Middle segment pancreatectomy was used in 12 consecutive patients with pancreatic tumors of the neck or body. The transected pancreatic head was sutured with duct ligation, and a Roux-en-Y loop of jejunum was anastomosed to the tail using mucosa-to-mucosa duct approximation and a 5F catheter for duct stenting and drainage. In 12 patients, 7 with cystic tumors (5 patients with serous cystadenoma; 2 patients with mucinous cystic neoplasms), 3 with islet cell adenomas, 1 with islet cell carcinoma, and 1 with intraductal papillary mucinous tumor, the tumor was resected by a middle segment pancreatectomy. In each case, the tumor, measuring 0.9 to 5.2 cm, lay in the neck or body of the pancreas and could not be safely enucleated without compromising the pancreatic duct. Each tumor was resected with clear margins. Two patients had a temporary pancreatic fistula; 1 patient had delayed gastric emptying. Median postoperative length of stay was 8 days. No patient became diabetic or required oral pancreatic enzyme supplements. No local recurrences occurred after a mean follow-up of 18 months. Middle segment pancreatectomy is a safe and effective technique for resecting selected pancreatic tumors in the neck and body of the pancreas while preserving pancreatic endocrine and exocrine function and the spleen.
Humans↗
Implications of peritoneal cytology for pancreatic cancer management.
OBJECTIVE: To assess the implications of positive cytology for malignant cells (positive results) from peritoneal washings in the management of patients with pancreatic cancer. DESIGN: Retrospective cohort study. SETTING: Referral practice in a university hospital. PATIENTS: A total of 32 consecutive pancreatic cancer patients with positive results from peritoneal washings during a 4-year period, 17 with visible biopsy-proven intraabdominal metastases at the time of laparoscopy or laparotomy and 15 without visible metastases. A treatment-matched control group of 30 patients was randomly selected from a group of 105 patients with negative cytology for malignant cells (negative results) from peritoneal-fluid cytology. INTERVENTIONS: Eight of 17 patients with visible metastases underwent treatment with chemotherapy, radiation, or both; 13 of the 15 patients with no visible metastases underwent further treatment, including pancreatic resection in 2 patients and external beam radiation in 13 patients (3 with intraoperative radiation therapy). MAIN OUTCOME MEASURES: Time to metastases and mortality. RESULTS: Median survival among patients with and without visible metastasis was 7.8 months and 8.6 months, respectively (P=.95), despite the fact that patients without visible metastases received more treatment. Patients without visible metastases at presentation were found to have metastatic disease as documented by computed tomographic scan or subsequent laparotomy at a median time of 2.9 months. The survival of treatment-matched patients with negative cytology was significantly longer (median, 13.5 months; P=.04). CONCLUSIONS: Pancreatic cancer patients with peritoneal micrometastases have a dismal outcome even without macroscopic metastases. Since these patients do not benefit from local therapy, the finding of a positive result from peritoneal-fluid cytologic testing contraindicates further irradiation or surgery, except for specific complications.
Cohort Studies↗
Metastases to the pancreas and their surgical extirpation.
BACKGROUND: The pancreas is an unusual but occasionally favored site for metastases, notably from carcinomas of the kidney and lung. The pancreas may be the only identified locus of spread, and therefore may provide an opportunity for significant palliation or even cure using pancreatectomy. OBJECTIVE: To report the treatment and outcome of patients presenting with metastases to the pancreas. DESIGN: Five-year survey. SETTING: Tertiary referral center. PATIENTS: Ten patients with apparently isolated metastases to the pancreas were identified from January 1, 1991, to December 31, 1995. All patients were followed up until death or to September 1997. RESULTS: The patients had been treated previously for carcinoma of the lung (n=4), renal cell carcinoma (n=2), sarcoma (n=2), breast carcinoma (n=1), and endometrial carcinoma (n=1). The interval between primary treatment and presentation of the metastases averaged 70 months (14-24 months for lung cancer, 10 and 22 years for renal cell carcinoma, 4 and 6 years for sarcoma, 8 years for breast cancer, and 36 months for endometrial carcinoma). Metastases were initially misdiagnosed as primary pancreatic cancers in 7 patients. In 4 patients (those with renal cell cancer and sarcomas), the tumor was completely resected using total pancreatectomy (n=3) or Whipple resection (n=1). Survival after diagnosis averaged 22 months. Two of the 4 patients undergoing pancreatic resection remain alive and well 20 and 25 months after pancreatectomy. CONCLUSIONS: The pancreas may be the presenting and perhaps sole locus for metastasis, typically years after treatment for certain extrapancreatic malignant neoplasms. Recognition and surgical treatment can provide worthwhile palliation and long-term survival.
Female↗
Gastrointestinal conditions.
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Appendicitis↗
Technetium-99m-labeled white blood cells: a new method to define the local and systemic role of leukocytes in acute experimental pancreatitis.
OBJECTIVE: We developed a new method to quantitate leukocyte accumulation in tissues and used it to examine the time course and severity of acute experimental pancreatitis. BACKGROUND: Leukocyte activation and infiltration are believed to be critical steps in the progression from mild to severe pancreatitis and responsible for many of its systemic complications. METHODS: Pancreatitis of graded severity was induced in Sprague-Dawley rats with a combination of caerulein and controlled intraductal infusion. Technetium-99m (99mTc)-labeled leukocytes were quantified in pancreas, lung, liver, spleen, and kidney and compared with myeloperoxidase activity. The severity of pancreatitis was ascertained by wet/dry weight ratio, plasma amylase, and trypsinogen activation peptide in the pancreas. The time course of leukocyte accumulation was determined over 24 hours. RESULTS: Pancreatic leukocyte infiltration correlated well with tissue myeloperoxidase concentrations. In mild pancreatitis, leukocytes accumulated only in the pancreas. Moderate and severe pancreatitis were characterized by much greater leukocyte infiltration in the pancreas than in mild disease (p < 0.01), and increased 99mTc radioactivity was detectable in the lung as early as 3 hours. 99mTc radioactivity correlated directly with the three levels of pancreatitis. CONCLUSIONS: Mild pancreatitis is characterized by low-level leukocyte activation and accumulation in the pancreas without recruitment of other organs; marked leukocyte accumulation was found in the pancreas and in the lung in more severe grades of pancreatitis. These findings provide a basis for the pathophysiologic production of cytokines and oxygen free radicals, which potentiate organ injury in severe pancreatitis. This study validates a new tool to study local and systemic effects of leukocytes in pancreatitis as well as new therapeutic hypotheses.
Acute Disease↗
Débridement and closed packing for the treatment of necrotizing pancreatitis.
OBJECTIVE: To evaluate the results of débridement and closed packing for necrotizing pancreatitis and to determine the optimal timing of surgical intervention based on patient outcomes. METHODS: Between February 1990 and November 1996, 64 consecutive patients with necrotizing pancreatitis were treated with necrosectomy followed by closed packing of the cavity with stuffed Penrose and closed suction drains. The mean APACHE II score immediately before surgery was 9, and 31% of the patients had organ failure. Patients were stratified with an outcome score based on death and major complications; this was correlated with the timing of surgical intervention. The data were then subjected to cut-point analysis by sequential group comparison. RESULTS: Patients underwent surgery a median of 31 days after diagnosis. Fifty-six percent had infected necrosis. The mortality rate was 6.2% and was no different in infected or sterile necrosis. Eleven patients required a second surgical procedure and 13 required percutaneous drainage; a single surgical procedure sufficed in 69%. Enteric fistulae occurred in 16% of patients. The mean hospital stay after surgery was 41 days, and the interval until return to regular activities was 147 days. A significant negative correlation between duration of pancreatitis and outcome scores was found, and sequential group comparison demonstrated that the change point at which significantly better outcomes were encountered was day 27. CONCLUSION: Débridement of pancreatic necrosis followed by closed packing and drainage is accomplished with a low mortality rate and reduced rates of complications and second surgical procedures. Although intervention is best deferred until the demarcation of necrosis is complete, delay beyond the fourth week confers no additional advantage.
APACHE↗
On the protective mechanisms of nitric oxide in acute pancreatitis.
BACKGROUND: Ectopic protease activation, microcirculatory changes, and leucocyte activation are the main events in the pathogenesis of acute pancreatitis. Nitric oxide (NO) is known to be a key mediator in the normal and inflamed pancreas. AIMS: To investigate the targets on which NO exerts its effect in caerulein induced pancreatitis. METHODS: Acute pancreatitis was induced in rats which additionally received either the NO synthase substrate, L-arginine; the NO donor, sodium nitroprusside; or the NO synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME). At six hours, pancreatic injury (oedema, leucocyte content, ectopic trypsinogen activation) was analysed and pancreatic oxygenation and perfusion were determined. A direct influence of NO on amylase secretion and trypsinogen activation was evaluated separately in vitro. RESULTS: Both NO donors reduced the grade of inflammation. L-NAME increased the severity of inflammation, while decreasing pancreatic tissue oxygenation. Although neither amylase secretion nor intracellular trypsinogen activation in caerulein stimulated pancreatic acini was influenced by either NO donors or inhibitors, both NO donors decreased intrapancreatic trypsinogen activation peptide (TAP) and pancreatic oedema in vivo, and L-NAME increased TAP. CONCLUSIONS: NO protects against injury caused by pancreatitis in the intact animal but has no discernible effect on isolated acini. It is likely that in pancreatitis NO acts indirectly via microcirculatory changes, including inhibition of leucocyte activation and preservation of capillary perfusion.
Acute Disease↗
Lexipafant fails to improve survival in severe necrotizing pancreatitis in rats.
CONCLUSION: Lexipafant administration fails to improve survival or lessen the disease severity in two experimental models of severe acute pancreatitis. BACKGROUND: The potent platelet activating factor antagonist Lexipafant has been shown to attenuate the biochemical and histologic changes associated with some animal models of acute pancreatitis, suggesting an important role for this cytokine in its pathogenesis. However, a survival advantage following Lexipafant administration has not been demonstrated. This study evaluates the effect of this platelet activating antagonist on survival in rat models of necrotizing and fulminant hemorrhagic pancreatitis. METHODS: Sprague-Dawley rats underwent induction of either acute necrotizing (n = 40) or hemorrhagic pancreatitis (n = 36) with a time- and pressure-controlled bile duct infusion of 10 mM glycodeoxycholic acid (GDOC) or enterokinase 15 U/mL, in combination with supramaximal cerulein stimulation (5 micrograms/kg/h). Immediately after pancreatitis induction, rats were randomly divided into three groups and received Lexipafant (1 mg or 10 mg) or saline as a continuous intravenous infusion over 9 h. Twenty-four-hour survival rates were determined and severity of pancreatitis was assessed by pancreatic histology scores. RESULTS: The survival rates for GDOC treated rats were 55% (saline), 50% (1 mg Lexipafant) and 50% (10 mg Lexipafant). As expected, all rats induced with enterokinase and treated with saline died with hemorrhagic pancreatitis within 24 h. The same was true of those treated with high- and low-dose Lexipafant, and there was no difference in survival time. Histology scores did not differ between Lexipafant-treated and control rats in either GDOC or enterokinase rats.
Animals↗
Outcomes of atypical symptoms attributed to gastroesophageal reflux treated by laparoscopic fundoplication.
BACKGROUND: The introduction of laparoscopic fundoplication (LF) has lowered the threshold for operation in patients with symptoms attributed to gastroesophageal reflux. We sought to determine whether the outcomes in patients referred for atypical symptoms (pulmonary, pharyngolaryngeal, and pain syndromes) were as good as those referred for correction of heartburn and regurgitation (typical symptoms). METHODS: Thirty-five of 150 consecutive patients undergoing LF with a minimum of 12 months of follow-up were referred primarily for correction of atypical symptoms. A standard preoperative evaluation included endoscopy, manometry, upper gastrointestinal contrast radiography, and 24-hour pH probe testing (33 of 35 patients with atypical symptoms). Patients completed a symptom questionnaire administered by a study nurse before the operation and 3 and 12 months after the operation. Symptoms were scored from 0 to 10. RESULTS: Heartburn was relieved by LF in 93% of patients, whereas only 56% of patients had relief of atypical symptoms. Furthermore, the degree of improvement in typical symptoms was greater than that seen for atypical symptoms as measured by the 0 to 10-symptom rating score (improvement in typical symptoms = 6.2 vs improvement in atypical symptoms = 4.4 [p = 0.01]). The response rate for laryngeal, pulmonary, and epigastric/chest pain symptoms was 78%, 58%, and 48%, respectively. Analysis of factors associated with relief of atypical symptoms revealed that response to a preoperative trial of omeprazole or H2-blockers was significantly associated with successful surgical outcome (p = 0.03). Six of seven patients with laryngeal symptoms who had acid reflux above the cricopharyngeal level shown by dual-probe pH testing had relief of the symptoms after LF. Manometric findings (amplitude of esophageal body contractions, propagation of contractions, and lower esophageal sphincter resting pressure) neither predicted nor correlated with relief of atypical symptoms after the operation. CONCLUSIONS: Relief of atypical symptoms attributed to gastroesophageal reflux by LF is less satisfactory and more difficult to predict than relief of heartburn and regurgitation. The only useful preoperative predictors of relief of atypical symptoms in this study were the response to pharmacologic acid suppression and dual-probe pH testing (only in patients with laryngeal symptoms).
Adult↗
The use of endoscopic ultrasonography to reduce the cost of treating ampullary tumors.
BACKGROUND: Local excision of selected ampullary tumors may result in the same benefit as Whipple resection with less morbidity and mortality. The purpose of this study was to determine if endoscopic ultrasonography could aid in the selection of patients for local resection and to determine if there was a significant cost difference between the two surgical procedures. METHODS: In this retrospective study of 32 patients who underwent surgery for ampullary tumors, endoscopic ultrasonography staging was performed in 18 patients. Resected specimens were used to determine pathologic staging. Local disease was defined as stage T2N0 or less. Cost data were available for 20 patients. RESULTS: The sensitivity and specificity of endoscopic ultrasonography for differentiating local from advanced ampullary tumors were both 83%. The median total cost for a local resection was $9314 versus $16,017 for a Whipple resection (p < 0.0017). CONCLUSION: Endoscopic ultrasonography is an effective tool for identifying patients with localized ampullary tumors. The cost of a local resection for ampullary tumors is significantly less than that of a Whipple resection. The use of endoscopic ultrasonography to select patients for local resection may be a cost-effective technique in the management of patients with ampullary tumors.
Adult↗
Differing roles of nitric oxide in the pathogenesis of acute edematous versus necrotizing pancreatitis.
BACKGROUND: Microcirculatory changes and leukocyte-endothelial interaction are both central to the pathogenesis of acute pancreatitis. We studied the effects of nitric oxide (NO) donors (intravenous or inhaled) and NO inhibitors, which affect each of these processes, on markers of experimental mild (edematous) and severe (necrotizing) pancreatitis in rats. METHODS: Mild pancreatitis was induced with intravenous cerulein (n = 100) and severe pancreatitis with intravenous cerulein and intraductal glycodeoxycholic acid (n = 100). Each group was randomly divided into five equal treatment subgroups: control, NO-synthase substrate L-arginine, NO donor sodium nitroprusside, NO-synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME), and NO-inhalation. After 6 hours edema was measured by a wet/dry weight ratio, and pancreatic injury was quantified by tissue levels of trypsinogen activation peptides (TAPs) and by histologic analysis of inflammation and necrosis. RESULTS: In mild pancreatitis (1) both NO donors reduced edema formation (p < 0.001) and also reduced intrapancreatic TAPs (p < 0.03); (2) L-NAME significantly increased tissue TAPs (p < 0.03); and (3) inhaled NO had no effect. In severe pancreatitis (1) both intravenous NO donors reduced edema formation (p < 0.005) and both markedly reduced intrapancreatic TAPs (p < 0.001); (2) L-NAME did not further increase the already high tissue TAPs; and (3) inhaled NO decreased tissue TAPs (p = 0.01). Evaluation of inflammation and necrosis by histologic scoring confirmed the reduction of pancreatic injury by NO donors and worsening with NO-synthase inhibitor. CONCLUSIONS: NO donors have a beneficial effect on edema formation in acute pancreatitis but confer more important protection against ectopic trypsinogen activation, which correlates with mortality, inflammation, and necrosis. Although direct microcirculatory action is likely, the salutary effect of inhaled NO in severe pancreatitis may suggest indirect action on circulating leukocytes, which are thought to potentiate tissue injury.
Amylases↗
Analysis of K-ras oncogene mutations in chronic pancreatitis with ductal hyperplasia.
BACKGROUND: K-ras oncogene mutations have been identified in up to 95% of pancreatic cancers, implying their critical role in their molecular pathogenesis. However, the earliest stage in which K-ras mutations can be detected in potential precursor lesions of pancreatic cancer remains unclear. This study evaluates pancreatic ductal hyperplasia in the setting of chronic pancreatitis, which predisposes to pancreatic cancer development, for K-ras codon 12 and 13 mutations. METHODS: Paraffin-embedded surgical specimens from 42 patients with chronic pancreatitis were examined microscopically for the presence of ductal hyperplasia. Both hyperplastic and nonhyperplastic ducts were microdissected from the specimens that contained hyperplasia (11 of 42). Four of the remaining specimens without hyperplasia served as controls. Genomic DNA was extracted, and polymerase chain reaction and amplification of the K-ras oncogene was performed. Polymerase chain reaction products were evaluated by means of hybridization to mutant specific oligonucleotide probes and by means of automated DNA sequencing. RESULTS: K-ras codon 12 mutations representing glycine to valine substitutions were present in 2 of (18%) 11 patients with ductal hyperplasia. No mutations were found in the controls without ductal hyperplasia. CONCLUSIONS: Our study supports the premise that K-ras mutations develop in a subset of chronic pancreatitis associated hyperplasia and provides a genetic basis for the potential progression of chronic pancreatitis to pancreatic cancer.
Adult↗