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Biomedical subjects

R M Walsh

Publications and source records attributed to R M Walsh.

At least 19 recordsLinked to original sources

Induction of nasal hyper-responsiveness by allergen challenge in allergic rhinitis: the role of afferent and efferent nerves.

BACKGROUND: Hyper-responsiveness of nasal secretory function and volume changes are features of allergic rhinitis (AR) that are mediated in part by neural mechanisms. The finding of nasal hyper-responsiveness in subjects with AR who are currently symptomatic, but not in those who are currently out of season and asymptomatic, suggests that induction of neural reflexes in allergic subjects occurs as a result of allergic inflammation. OBJECTIVES: To investigate whether allergen exposure in subjects with asymptomatic seasonal allergic rhinitis (SAR) may lead to induction of neural reflexes, and to investigate the components of the reflexes involved in this induction. METHODS: Asymptomatic subjects with (out-of-season) SAR underwent a nasal bradykinin challenge, before and 24 h after preceding ipsilateral (n = 11) and contralateral (n = 11) antigen challenge. Challenges were performed and nasal secretions collected using filter paper disks, and changes in nasal minimal cross-sectional area (A(min)) were measured using acoustic rhinometry. RESULTS: Preceding ipsilateral antigen challenge led to the induction of a contralateral secretory reflex (P = 0.01), which was absent in control experiments (P = 0.34). Ipsilateral secretion weights were also enhanced. Preceding contralateral antigen challenge also induced a contralateral secretory reflex (P = 0.03). Enhancement of the reduction in contralateral A(min) was also seen (P = 0.02). Ipsilateral responses were unchanged. CONCLUSIONS: Allergen exposure in asymptomatic allergic subjects leads to induction of neural reflexes, resulting in nasal hyper-responsiveness, which persists beyond the resolution of the acute allergic response. Our data suggest that the mechanisms of allergen-induced hyper-responsiveness involve both afferent and efferent components.

Adolescent↗

Conservative management of vestibular schwannomas - second review of a prospective longitudinal study.

Vestibular schwannomas have been traditionally managed with microsurgical removal and in recent years, stereotactic radiotherapy. However, there is a group of patients in whom a conservative management approach might represent a desirable alternative. The aim of this study was to determine the natural history and outcome following the conservative management of 72 patients with unilateral vestibular schwannomas. This is a prospective cohort review of a previously published group of patients [Clin. Otolaryngol. (2000) 25, 28-39] with unilateral vestibular schwannoma that were initially analysed at our institution in 1998 [Walsh R.M., Bath A.P., Bance M.L. et al., Clin. Otolaryngol. (2000) 25, 28]. The mean duration of follow-up was 80 months (range 52-242 months). All the patients in the study underwent serial magnetic resonance imaging (MRI) for assessment of tumour growth. Patients were deemed to have failed conservative management if there was evidence of rapid radiological tumour growth and/or increasing signs and symptoms, which necessitated active intervention. The mean tumour growth rate for the entire group at the second review was 1 mm/year (range -0.84-9.65 mm/year). The mean growth rate for cerebellopontine angle tumours (1.3 mm/year) was significantly greater than that of internal auditory canal (IAC) tumours (0 mm/year) (P = 0.005). The majority of tumours (87.14%) grew <2 mm/year. There was significant tumour growth seen in 38.9%, no or insignificant growth in 41.7%, and negative growth in 19.4%. Twenty-three patients (32%) failed conservative management at the second review. There was no difference in the outcome of these failed patients in comparison with patients who underwent primary treatment without a period of conservative management. The mean growth rate of tumours in patients that failed conservative management (3.1 mm/year) was significantly greater than that in patients who did not fail (0.2 mm/year) (P < 0.001). No factors predictive of tumour growth or failure of conservative management were identified. Hearing deterioration with pure tone averages (0.5, 1, 2, 3 kHz) and speech discrimination scores occurred irrespective of tumour growth. This prospective study further emphasizes the role of conservative management in selected cases of vestibular schwannomas. Tumours in this study confined to the IAC typically demonstrated minimal or no growth on serial MRI scanning. Regular follow-up with interval scanning is mandatory in all patients.

Adult↗

Laparoscopic splenectomy for lymphoproliferative disease.

BACKGROUND: Elective laparoscopic splenectomy (LS) achieves excellent results for benign hematologic diseases. The role of LS for hematologic malignancies is harder to define owing to associated splenomegaly and patient disease that may alter outcome. METHODS: Retrospective review of single institution experience 1996 through 2002. To limit variability of disease processes, only patients with immune thrombocytopenic purpura (ITP) and lymphoproliferative disease (LPD) were studied. RESULTS: A total of 211 LS have been performed, including 73 for LPD and 86 for ITP. Patients with LPD were significantly older, 61 vs 46 years p<0.001; male, 45 (62%) vs 33 (38%), p<0.001; and larger splenic weight, 680 vs 162 g, p<0.001. Fifty-nine patients (81%) with LPD were operated with standard LS with a conversion rate of 15%. Hand-assisted LS was performed in 14 patients (19%), and three were converted to open. Compared to ITP, patients with LPD had longer operative time, 148 vs 126 min, p<0001, and higher blood loss, 200 vs 100 cc, p = 0.004. There was one mortality (0.6%), and morbidity occurred in six patients (8%) with LPD and seven (8%) with ITP. The median length of stay was 3 days for LPD and 2 days for ITP, p = 0.03. Forty-six patients were principally operated for a diagnosis, and 27 (60%) were found to have lymphoma. CONCLUSIONS: LS can be performed safely in patients with LPD, and when used judiciously with hand-assisted techniques can be performed with low conversion and morbidity rates. Splenectomy plays an important role in establishing the diagnosis of lymphoma in LPD.

Adult↗

Imaging for the diagnosis and staging of periampullary carcinomas.

Multiple imaging modalities are available for investigating patients with a suspected periampullary neoplasm. The relative utility of each imaging modality is discussed regarding its role in diagnosis and staging. A general imaging approach to patients with a distal biliary obstruction also is presented.

Ampulla of Vater↗

Determination of intact splenic weight based on morcellated weight.

BACKGROUND: Comparisons of splenic size based on splenic weight are difficult after laparoscopic splenectomy, which results in a morcellated specimen. We report the results of a direct comparison between morcellated and intact splenic weights. METHODS: Porcine spleens were harvested via a midline laparotomy, and an intact splenic weight was obtained, which served as the control. The spleen then was placed into an impermeable retrieval bag and returned to the peritoneal cavity. A separate 10-mm incision was made and the spleen mechanically morcellated with a uterine forceps. This design most faithfully recreates the morcellation process during laparoscopic splenectomy in humans. The aggregate weight of the fragments was compared with intact splenic weight. RESULTS: Intact and morcellated weights were obtained from 58 porcine spleens. The mean intact splenic weight was 145 g, and the mean morcellated weight was 78 g. For a given morcellated weight achieved at laparoscopic splenectomy, an estimated intact weight can be determined by the following formula: intact weight (g) = morcellated weight (g) x 1.34 + 45. CONCLUSIONS: On the basis of our calculations, a normal spleen weighing 150 g would have a mean morcellated weight of 78 g, and splenomegaly (intact spleen weighing 250 g or more) would be defined by a morcellated weight exceeding 153 g.

Animals↗

Recurrence after laparoscopic ventral hernia repair.

BACKGROUND: Although the early results of laparoscopic ventral hernia repair have shown a low recurrence rate, there is a paucity of long-term data. This study reviews a single institution's experience with laparoscopic ventral hernia repair (LVHR). METHODS: We carried out a retrospective analysis of all LVHR performed at the Cleveland Clinic Foundation from January 1996 to March 2001. Recurrence rates were determined by physical exam or telephone follow-up. Factors predictive of recurrence were determined using Cox regression. RESULTS: Of 100 ventral hernias completed laparoscopically, 96 were available for long-term follow-up (average, 30 months; range 4-65). There were no deaths and major morbidity occurred in seven patients. Recurrences were identified in 17 patients. Nine recurrences occurred in the 1st postoperative year; however, hernia recurrence continued throughout the period of follow-up. Multivariate analysis showed that a prior failed hernia repair was associated with a more likely chance of another recurrence (65% vs 35%, odds ratio (OR) 3.6; p = 0.05) and that an increased estimated blood loss (106 cc vs 51 cc, OR 1.03; p = 0.005) predicted recurrence. Other variables, including body mass index (BMI) (32 vs 31 kg/m2, p = 0.38), defect size (115 cm2 vs 91 cm2; p = 0.23), size of mesh (468 cm2 vs 334 cm2, p = 0.19), type of mesh (p = 0.62), and mesh fixation (p = 0.99), did not predict recurrence. An additional 14 cases required conversion to an open operation, and seven of these cases (50%) had recurrence on long-term follow-up. CONCLUSION: Although LVHR remains the preferred method of hernia repair at our institution, this study documents a higher recurrence rate than many other short-term series. There results underscore the importance of long-term follow-up in assessing hernia surgery outcome.

Adult↗

Retained gallbladder/cystic duct remnant calculi as a cause of postcholecystectomy pain.

BACKGROUND: Pain following cholecystectomy can pose a diagnostic and therapeutic dilemma. We reviewed our experience with calculi retained in gallbladder and cystic duct remnants that present with recurrent biliary symptoms. METHODS: Over the last 6 years, seven patients were referred to us for the evaluation of recurrent biliary colic or jaundice. There were four men and three women ranging in age from 35 to 70 years. All seven had biliary pain similar to the symptoms that precede cholecystectomy; two of them also had also associated jaundice and one had pancreatitis. The time from cholecystectomy to onset of symptoms ranged from 14 months to 20 years (median, 8.5 Years). Four had undergone laparoscopic cholecystectomy and three had had an open cholecystectomy; none had an operative cholangiogram. RESULTS: Five of seven underwent diagnostic endoscopic retrograde cholangiography (ERC), which revealed obvious filling defects in the cystic duct or gallbladder remnant. The final patient was diagnosed by laparoscopic ultrasound after eight negative radiographic studies. Four patients underwent laparotomy and resection of a retained gallbladder and/or cystic duct. Two patients were treated with extracorporeal shock-wave lithotripsy (ESWL); one of them also required endoscopic biliary holmium laser lithotripsy. One patient underwent successful repeat laparoscopic cholecystectomy. There were no treatment-related complications. At a median follow-up of 11.5 months, all have achieved complete stone clearance and are asymptomatic. CONCLUSION: Retained gallbladder and cystic duct calculi can be a source of recurrent biliary pain, and a heightened suspicion may be required to make the diagnosis. This entity can be prevented by accurate identification of the gallbladder-cystic duct junction at cholecystectomy and by routine use of cholangiography. A variety of therapeutic options can be employed to obtain a successful outcome.

Adult↗

Laparoscopic vs open resection of gastric stromal tumors.

BACKGROUND: Gastric stromal tumors are rare neoplasms that may be benign or malignant. Given that malignant gastric stromal tumors rarely involve lymph nodes and require excision with negative margins, they appear amendable to laparoscopic excision. There are few reports of laparoscopic resection, and no comparisons have been done between laparoscopic and open surgery. This study compares the relative efficacy of the two approaches. METHODS: Between May 1994 and December 2000, 33 patients underwent 35 operations for gastric stromal tumors. Laparoscopic resections were performed in 21 patients; open resections were done in 12 patients. The medical records of the patients were reviewed retrospectively with regard to operating time, blood loss, length of stay, and clinical course. RESULTS: Patient demographics, tumor characteristics (mean tumor size, benign vs malignant), and presenting symptoms were similar for both groups. In the laparoscopic group, 15 wedge resections; three partial gastrectomies, and three transgastric needlescopic enucleations were performed. In the open group, six wedge resections, four antrectomies, and two partial proximal gastrectomies were performed. There were no significant differences in mean operative time (169 vs 160 min), mean estimated blood loss (106 vs 129 cc), or perioperative complication rate (9.5% vs 8.3%) between the laparoscopic and open groups, respectively. The mean length of stay was significantly less (p<0.05) in the laparoscopic group (3.8 vs 6.2 days). Average follow-up was 1.5 years. One patient in each group has died due to metastatic disease. There have been no trocar site recurrences. CONCLUSIONS: Laparoscopic resection of gastric stromal tumors is safe and appropriate. Tumor size, operating time, and estimated blood loss were equivalent to the open approach, and there was a statistically shorter hospital stay in the laparoscopic group.

Adult↗

Laparoscopic splenectomy.

BACKGROUND: Laparoscopic splenectomy is currently the procedure of choice for elective splenectomy. This study reviews the initial 100 laparoscopic splenectomies completed at the Cleveland Clinic Foundation. METHODS: A retrospective review of elective laparoscopic splenectomy was performed to assess clinical outcomes at the Cleveland Clinic Foundation. Patient demographics, preoperative diagnoses, operative characteristics, morbidity, and mortality were evaluated. RESULTS: Of the 169 elective splenectomies completed over a 4-year period from 1995 to 1999, 100 were attempted laparoscopically. The proportions of all splenectomies attempted laparoscopically by year were 17%, 38%, 75%, and 72%. Nearly 70% of splenectomies were performed for idiopathic thrombocytopenic purpura or malignancy. Overall, the mean blood loss was 181 ml, and the mean operative time was 170 min. Splenomegaly occurred in 31% of the patients and accounted for longer operative times. Three patients required conversion to an open procedure. Postoperative complications were seen in 13% of the patients. One patient died in the postoperative period from staphylococcal sepsis, giving a mortality rate of 1%. CONCLUSIONS: Laparoscopic splenectomy currently is the procedure of choice for elective splenectomy at our institution. As compared with traditional open splenectomy, laparoscopic splenectomy results in minimal morbidity even in the setting of splenomegaly.

Elective Surgical Procedures↗

Somatostatin therapy for glomus tumors: a report of two cases.

Glomus tumors of the head and neck are benign vascular lesions that often provide dilemmas in management. The presence of somatostatin receptors on the tumor cell surface has facilitated an additional imaging technique in the form of radiolabeled octreotide scanning. The use of the somatostatin analogue, octreotide, also provides a therapeutic option for inoperable or recurrent tumors. We present two patients, one with a surgically inaccessible tumor that recurred after primary radiotherapy and one who underwent incomplete resection because of the tumor's proximity to the internal carotid artery. Neither tumor has shown further growth 5 and 3 years after treatment with octreotide, respectively.

Case Reports↗

Application of the U and gamma' models in binary sweet taste mixtures.

The U and Gamma' models of sensory interactions, successfully applied in olfaction for several years, are tested here using data from published studies on sweetness. The models are subsequently tested on new data obtained in studies of binary mixtures of four sodium sulfamates. The U model allows for the estimation of a global interaction, whereas the Gamma' model allows for the distinction between that which is due to an intrinsic interaction in the mixture itself and that which may be due to the power function exponents in the mixture. The models give satisfactory predictions for observed phenomena of sweet taste suppression, synergism or pure additivity. Additionally, they appear to be more suitable than other models recently applied in taste, particularly the equiratio model. Application of the models to the sulfamate mixtures, reveals additivity for sodium cyclohexylsulfamate (cyclamate)/potassium cyclohexylsulfamate and sodium cyclohexylsulfamate/sodium exo-2-norbornylsulfamate, respectively; whereas for sodium cyclohexylsulfamate/sodium 3-bromophenylsulfamate, the models revealed a slight hypo addition which is simply due to the dissimilarity values of the power function exponents of the components.

Aspartame↗

Outcome of laparoscopic splenectomy based on hematologic indication.

BACKGROUND: Laparoscopic splenectomy is the procedure of choice for elective splenectomy at the Cleveland Clinic Foundation. Although the literature clearly documents the technical feasibility and safety of laparoscopic splenectomy, little data exists concerning the results of this procedure based on the hematologic indication for splenectomy. We sought to examine the clinical experience with laparoscopic splenectomy in a single institution, with particular attention to morbidity and clinical outcomes based on hematologic disease process. METHODS: This study retrospectively reviewed a consecutive series of laparoscopic splenectomies performed for nontraumatic, splenic pathology at the Cleveland Clinic Foundation from August 1995 to January 2001. Patient demographics, operative indications, morbidity, mortality, and clinical outcome were evaluated. Hematologic diagnostic groups were compared using Fisher's exact tests and Wilcoxon rank-sum tests. RESULTS: A total of 147 laparoscopic splenectomies were performed. Seven patients (5%) required conversion to open splenectomy. Indications for splenectomy included idiopathic thrombocytopenic purpura (ITP) in 65 patients, hematologic malignancy in 43 patients, autoimmune hemolytic anemia (AIHA) in 9 patients, thrombotic thrombocytopenic purpura (TTP) in 9 patients, splenomegaly in 5 patients, splenic cyst in 4 patients, splenic abscess in 3 patients, hereditary spherocytosis in 2 patients, splenic artery aneurysm in 2 patients, Felty's syndrome in 1 patient, myelofibrosis in 1 patient, and other in 3 patients. Accessory spleens were identified in 20 patients (14%). Postoperative complications occurred in 23 (16%) patients. Patients with ITP had significantly shorter operation times (134 vs 163 min; p = 0.001), decreased estimated blood loss (126 vs 307 ml; p = 0.001), decreased length of hospital stay (2.8 vs 4.6 days; p < 0.001), and less chance of conversion (0 vs 7; p = 0.02) than patients with any other diagnosis. A mean follow-up period of 20 +/- 14 months showed an 85% rate of remission for ITP, 89% for TTP, and 89% for AIHA. Patients with malignant disease had significantly larger spleens (822 vs 313 g; p < 0.001), more estimated blood loss (380 vs 168 ml; p = 0.04), and longer operative times (170 vs 142 min; p = 0.009), as compared patients treated for benign disease. However, the length of hospital stay (4.3 vs 3.6 days; p = 0.06) and complication rates (19% vs 14%; p = 0.08) were not significantly different between the two groups. CONCLUSIONS: When performed for ITP, laparoscopic splenectomy resulted in shorter operations, minimal blood loss, earlier discharge, no conversions, and excellent remission rates, as compared with other hematologic indications. Despite larger spleens, more blood loss, and longer operations in patients with hematologic malignancies, morbidity and length of hospital stay still were similar to those associated with benign indications for laparoscopic splenectomy. In conclusion, laparoscopic splenectomy is safe and efficacious for a multitude of benign and malignant hematologic indications, and our data compares favorably to those for open series.

Adolescent↗

Pancreatic complications following laparoscopic splenectomy.

BACKGROUND: Laparoscopic splenectomy (LS) has been widely accepted despite a paucity of outcome data. Therefore, we performed a review of LS to assess the pancreatic complications and outcomes associated with this procedure. METHODS: Ninety-four splenectomies were performed for a variety of hematologic disorders. The patient was placed in the lateral position, and three or four trocars were used. RESULTS: LS was completed successfully in 93 patients. One case was converted to an open splenectomy for suspected gastrotomy. Thirty of 32 patients with splenomegaly underwent successful LS. Fifteen patients (16%) had some evidence of pancreatic injury. Six patients had asymptomatic hyperamylasemia. An injury directly associated with an adverse outcome occurred in nine cases (9.5% overall); six patients had pancreatic collections, one had a pancreatic fistula, and two developed hyperamylasemia and pain altering the length of hospitalization. Four of these nine patients did not have elevated postoperative amylase levels and were readmitted with pancreatic complications. CONCLUSIONS: LS can be performed for most pathologic conditions. Pancreatic injury is the most common morbidity associated with LS. The detection of hyperamylasemia can alert the surgeon to a pancreatic injury and alter postoperative management.

Fungemia↗

Treatment of intractable epistaxis using arterial embolization.

Arterial embolization has become the procedure of choice for managing intractable epistaxis in certain centres in North America and Europe, with arterial ligation reserved for those patients in which it fails. In Ireland, the role of this relatively new technique is poorly defined. The aim of this retrospective study was to investigate the outcome of all patients who underwent arterial embolization for intractable epistaxis in Dublin since it was introduced in 1998. Embolization resulted in complete and immediate resolution of epistaxis in 10 out of 12 patients (82%). Two patients required carotid ligation because of persistent epistaxis. One other patient had a further minor epistaxis 2 days following embolization, which was treated successfully with cautery. No major complications occurred in any of the patients. This study suggests that arterial embolization is an effective and safe method of managing patients with intractable epistaxis.

Adult↗

Intracranial complications of acute frontal sinusitis.

Despite advances in the diagnosis and treatment of acute frontal sinusitis, there is still significant occurrence of intracranial complications. Urgent surgical evacuation of any intracranial collection is required; however, the surgical management of the associated sinusitis remains controversial. Ten patients presented to this department over a 12-month period with subdural empyema secondary to acute frontal sinusitis. Four patients had a coexisting Pott's puffy tumour and one patient had a periorbital abscess. Each patient was managed using a multidisciplinary approach. A frontal sinus trephine/drain +/- antral washout was performed at the same time as craniotomy with evacuation of the empyema. With this approach only two patients suffered long-term morbidity in our series, in the form of persistent neurological or cognitive deficit. No patient required a definitive sinus procedure. This study emphasizes the need for the early assessment and intervention of patients with an intracranial complication secondary to acute frontal sinusitis. Further assessment of the underlying sinus disease is indicated during outpatient follow up after the acute episode.

Acute Disease↗

Loss of interstitial cells of cajal and inhibitory innervation in insulin-dependent diabetes.

BACKGROUND & AIMS: Gastrointestinal complications of long-standing diabetes include nausea, vomiting, abdominal pain, diarrhea, and constipation. The pathophysiology underlying these symptoms is poorly understood. Recent evidence suggests an important role for interstitial cells of Cajal in controlling gastrointestinal motility. The aim of this study was to determine changes in interstitial cells of Cajal and enteric innervation in a patient with insulin-dependent diabetes. METHODS: A full thickness jejunal biopsy was obtained from a 38-year-old insulin-dependent diabetic with evidence for diabetic gastroenteropathy. Immunohistochemistry, confocal microscopy, and 3-dimensional reconstruction techniques were used to quantify changes in the volume of interstitial cells of Cajal and enteric innervation. RESULTS: Interstitial cells of Cajal were markedly decreased throughout the entire thickness of the jejunum. A decrease in neuronal nitric oxide synthase, vasoactive intestinal peptide, PACAP, and tyrosine hydroxylase immunopositive nerve fibers was observed in circular muscle layer while substance P immunoreactivity was increased. CONCLUSIONS: The data suggest that long-standing diabetes is associated with a decrease in interstitial cells of Cajal volume and a decrease in inhibitory innervation, associated with an increase in excitatory innervation. The changes in interstitial cells of Cajal volume and enteric nerves may underlie the pathophysiology of gastrointestinal complications associated with diabetes and suggest future therapeutic targets.

Adult↗

Role of differential neuroaxial blockade in the evaluation and management of pain in chronic pancreatitis.

OBJECTIVES: Chronic pancreatic pain is difficult to treat. Surgical and medical therapies directed at reducing pain have met with little long-term success. In addition, there are no reliable predictors of response including pancreatic duct diameter. A differential neuroaxial blockade allows characterization of chronic abdominal pain into visceral and nonvisceral pain origins and may be useful as a guide to the treatment. Pain from an inflamed, and scarred pancreas should be visceral in origin. The purpose of our study was to determine the frequency with which patients with chronic pancreatitis have visceral pain and whether our modified differential neuroaxial blockade technique using thoracic epidural analgesia can accurately predict which patients will respond to medical or surgical therapy. METHODS: We retrospectively reviewed the medical records of patients with a firmly established diagnosis of chronic pancreatitis (Cambridge classification, calcifications) who had undergone a differential neuroaxial block for their chronic abdominal pain evaluation. Patient demographics and medical or surgical treatment for pancreatic pain was recorded. Response to therapy was defined by a 50% reduction in pain by verbal response score. RESULTS: A total of 23 patients were identified. Alcohol was the most common etiology for chronic pancreatitis (15 of 23, 55%). Surprisingly, the majority of chronic pancreatitis patients had nonvisceral pain (18 of 23, 78%) and only 22% (5 of 23) had visceral pain by differential neuroaxial block. Four of five patients (80%) with visceral pain responded to therapy, whereas only 5 of 17 (29%) of patients with nonvisceral pain responded. CONCLUSIONS: Surprisingly, patients with chronic pancreatitis commonly have nonvisceral pain. Differential neuroaxial blockade can predict which patients will respond to therapy.

Analgesia, Epidural↗