Predictors of response after laparoscopic splenectomy for immune thrombocytopenic purpura.

BACKGROUND: Splenectomy has been shown to produce long term remission in patients with immune thrombocytopenic purpura (ITP). With the development of laparoscopic splenectomy, there is renewed interest in the surgical treatment of ITP. The aim of this study was to identify factors that are predictive of outcome after laparoscopic splenectomy for ITP. METHODS: A case series of 67 consecutive patients with ITP undergoing laparoscopic splenectomy was reviewed. A positive response was defined as a postoperative platelet count greater than 150,000/ml requiring no maintenance medical therapy on follow-up evaluation. A chi-square test and a stepwise logistic regression analysis were performed for the following variables: age, gender, preoperative response to steroids, duration of disease, severity of preoperative bleeding, accessory spleens, and thrombocytosis on discharge. RESULTS: At a median follow-up period of 38 months (range, 2-56 months), 52 patients (78%) had a positive response to laparoscopic splenectomy. Of the 15 patients (22%) who did not have a positive response, 11 were refractory and 4 relapsed. All relapses occurred in patients with a platelet count less than 150,000/microl at discharge. Patient age was the most significant predictive factor for success or failure of the operation. The median age of the responders (31 years; range, 19-71 years) was significantly lower than the median age of the nonresponders (49 years; range, 24-62; p < 0.001). Only 5.6% of those younger than 40 years did not have a positive response, compared with 42% of patients older than 40 years (p < 0.05). Patient age was significantly associated with outcome on univariable chi-square analysis (p = 0.001), and was the only significant factor on multivariable analysis (odds ratio, 2.65; 95% confidence interval, 1.71-4.1). Other significant predictors of outcome on univariable analysis were preoperative response to corticosteroids and platelet count on discharge. CONCLUSIONS: A long-lasting response after splenectomy for ITP is more likely to occur in patients younger than 40 years of age. To avoid the long-term side effects of corticosteroid use, early surgical referral of younger patients with ITP should be considered.

Use of fibrin sealant for prosthetic mesh fixation in laparoscopic extraperitoneal inguinal hernia repair.

OBJECTIVE: To evaluate the efficacy of mesh fixation with fibrin sealant (FS) in laparoscopic preperitoneal inguinal hernia repair and to compare it with stapled fixation. SUMMARY BACKGROUND DATA: Laparoscopic hernia repair involves the fixation of the prosthetic mesh in the preperitoneal space with staples to avoid displacement leading to recurrence. The use of staples is associated with a small but significant number of complications, mainly nerve injury and hematomas. FS (Tisseel) is a biodegradable adhesive obtained by a combination of human-derived fibrinogen and thrombin, duplicating the last step of the coagulation cascade. It can be used as an alternative method of fixation. METHODS: A prosthetic mesh was placed laparoscopically into the preperitoneal space in both groins in 25 female pigs and fixed with either FS or staples or left without fixation. The method of fixation was chosen by randomization. The pigs were killed after 12 days to assess early graft incorporation. The following outcome measures were evaluated: macroscopic findings, including graft alignment and motion, tensile strength between the grafts and surrounding tissues, and histologic findings (fibrous reaction and inflammatory response). RESULTS: The procedures were completed laparoscopically in 49 sites. Eighteen grafts were fixed with FS and 16 with staples; 15 were not fixed. There was no significant difference in graft motion between the FS and stapled groups, but the nonfixed mesh had significantly more graft motion than in either of the fixed groups. There was no significant difference in median tensile strength between the FS and stapled groups. The tensile strength in the nonfixed group was significantly lower than the other two groups. FS triggered a significantly stronger fibrous reaction and inflammatory response than in the stapled and control groups. No infection related to method of fixation was observed in any group. CONCLUSION: An adequate mesh fixation in the extraperitoneal inguinal area can be accomplished using FS. This method is mechanically equivalent to the fixation achieved by staples and superior to nonfixed grafts. Biologic soft fixation with FS will prevent early graft migration and will avoid the complications associated with staple use.

Laparoscopic repair of chronic intrathoracic gastric volvulus.

BACKGROUND: Totally intrathoracic gastric volvulus is an uncommon presentation of hiatal hernia, in which the stomach undergoes organoaxial torsion predisposing the herniated stomach to strangulation and necrosis. This may occur as a surgical emergency, but some patients present with only chronic, non-specific symptoms and can be treated electively. The aim of this study is to describe a comprehensive approach to laparoscopic repair of chronic intrathoracic gastric volvulus and to critically assess the pre-operative work-up. METHODS: Eight patients (median age, 71 years) underwent complete laparoscopic repair of chronic intrathoracic gastric volvulus. Symptoms of epigastric pain and early satiety were universally present. Five patients had reflux symptoms. The diagnostic evaluation included a video esophagogram, upper endoscopy, 24-hour pH measurement, and esophageal manometry in all patients. Operative results and postoperative outcome were recorded and follow-up at 1 year included a barium swallow in all patients. RESULTS: All patients had documented intrathoracic stomach. Five of 8 patients had a structurally normal lower esophageal sphincter. All 4 patients with reflux esophagitis on upper endoscopy had a positive 24-hour pH study, and 2 of these patients had a structurally defective lower esophageal sphincter on manometry. None of the patients had preoperative evidence of esophageal shortening. All procedures were completed laparoscopically. The procedure included reduction of the stomach into the abdomen, primary closure of the diaphragmatic defect, and the construction of a short, floppy Nissen fundoplication. There were no major complications. One patient required repair of a trocar site hernia 6 months postoperatively. At 1-year follow-up, there were no radiologic recurrences of the volvulus. One patient complained of temporary swallowing discomfort and another had recurrent gastroesophageal reflux disease (GERD) symptoms caused by a breakdown of the wrap. All other patients remained asymptomatic during follow-up. CONCLUSIONS: The repair of chronic gastric volvulus can be accomplished successfully with a laparoscopic approach. A preoperative endoscopy and esophagogram are crucial to detect esophageal stricture or shortening, and manometry is needed to access esophageal motility; pH measurements do not affect operative strategy. The procedure should include a Nissen fundoplication to treat preoperative GERD, to prevent possible postoperative GERD, and to secure the stomach in the abdomen. The procedure is safe but technically challenging, requiring previous laparoscopic foregut surgical expertise.

Reoperations after myopic laser in situ keratomileusis.

PURPOSE: To evaluate the results after enhancement of myopic laser in situ keratomileusis (LASIK) using the VISX Star excimer laser. SETTING: The Buzard Eye Institute, Las Vegas, Nevada, USA. METHODS: In this prospective study, 52 eyes of 40 patients had LASIK enhancement. The existing flap was lifted and the excimer laser treatment reapplied for the residual refractive error. The VISX Star excimer laser was used for the primary LASIK and the enhancement procedure. Retreatments for undercorrection, regression, and overcorrection were performed after 6 weeks and up to 40 weeks after the primary LASIK. Follow-up was 96% at 1 month, 67% at 6 months, and 71% at 12 months. RESULTS: Mean pre-enhancement spherical equivalent was -0.77 diopters (D) +/- 0.94 (SD) and mean uncorrected visual acuity (UCVA), 20/60. One year after the enhancement, mean spherical equivalent was -0.13 +/- 0.33 D, and mean UCVA was 20/25. Refraction remained stable during the 1 year follow-up, with no treatment required. After the enhancement, all patients had a UCVA of 20/40 or better. At 1 year, 3% of patients had lost 1 line of best corrected visual acuity and 32% had gained 1 line. No epithelial ingrowth was noted. CONCLUSION: Retreatment for LASIK beginning 6 weeks after the initial procedure proved to be effective with minimal complications and good results. The technique to raise and reposition the flap appeared safe, and complications were few.

Intraabdominal abscess rate after laparoscopic appendectomy.

BACKGROUND: Studies suggest increased intraabdominal abscess (IA) rates following laparoscopic appendectomy (LA), especially for perforated appendicitis. Consequently, an open approach has been advocated. The aim of our study is to compare IA rates following LA performed by a laparoscopic surgery and a general surgical service within the same institution. METHODS: Data of LA patients treated at Los Angeles County-University of Southern California (LAC-USC) Medical Center between March 1992 and June 1997 were reviewed. The main outcome measure was postoperative IA. RESULTS: In all, 645 LA were reviewed. A total of 413 LA (285 acute, 61 gangrenous, 67 perforated appendicitis) were performed by three general surgical services (10 attendings). Ten abscesses occurred postoperatively (2.4%), 6 with perforated appendicitis. After the laparoscopic service was introduced, 232 standardized LA (126 acute, 46 gangrenous, 60 perforated) were performed by two attendings. One IA occurred (gangrenous appendicitis). The IA rate for perforated appendicitis was significantly lower on the laparoscopic service (P = 0.025). There was no difference in IA rates for acute and gangrenous appendicitis. There was no mortality in either group. CONCLUSION: IA rate following LA for perforated appendicitis was significantly reduced on the laparoscopic service. Mastery of the learning curve and addition of specific surgical techniques explained this improved result. Therefore, laparoscopic appendectomy for complicated appendicitis may not be contraindicated, even for perforated appendicitis.

Mild form of Maroteaux-Lamy syndrome: corneal histopathology and ultrastructure.

PURPOSE: Maroteaux-Lamy syndrome is one of the mucopolysaccharidoses (MPSs) that is caused by the incomplete degradation and storage of dermatan sulfate. METHODS: We describe a 49-year-old female patient with the mild form of the disease (MPS VI-B) who developed bilateral increasing corneal opacification and increased intraocular pressure after cervical-fusion surgery. After treatment of the increased intraocular pressure, she underwent a penetrating keratoplasty of her right eye. RESULTS: The histopathologic and ultrastructural features of the corneal button were the accumulation of membrane-bound vacuoles containing fibrillogranular and lamellated material in keratocytes and endothelial cells and thinning of Descemet's membrane with excrescences. CONCLUSION: Our review of the literature reveals only two prior histologic studies of corneas affected by MPS VI B.

Effect of hemorrhage on superior mesenteric artery flow during increased intra-abdominal pressures.

BACKGROUND: Elevations in intra-abdominal pressure (IAP) adversely affect organ function. Prior hemorrhage and resuscitation exacerbates the cardiac and pulmonary effects of IAP. We have recently shown that superior mesenteric artery flow (SMAF) is reduced with increasing IAP. This study was designed to determine whether and how hemorrhage and resuscitation affects SMAF with increasing IAP. METHODS: Ten pigs were divided into two groups after placement of a Doppler flow probe around the proximal SMA and insertion of a pulmonary artery (PA) catheter. Group 1 underwent intraperitoneal infusion of fluid to increase IAP to 10, 20, 30, and 40 mm Hg followed by a 20-minute equilibration period at each IAP. Group 2 was hemorrhaged 20% of circulating volume followed by standard resuscitation. After equilibration, this group had IAP increased in the same manner as group 1. Cardiac output (CO), PA pressures, and SMAF were recorded 1 hour after laparotomy and after equilibration at each IAP. Comparisons were made using repeated measures of analysis of variance, Student's t test, and linear regression analysis. RESULTS: In group 2, a reduction in SMAF was noted at 30 and 40 mm Hg of IAP when compared with baseline (p = 0.009). This reduction was not seen in group 1. There was also a significant (p = 0.001) reduction in CO between baseline and all levels of increased IAP in group 2. This decrease was again not seen in group 1. The correlation between CO and SMAF in group 2 was r = 0.74, r2 = 0.55, p = 0.0001. There was no significant correlation between CO and SMAF in group 1. CONCLUSION: SMAF and CO are reduced with increasing IAP to a greater degree when preceded by hemorrhage and resuscitation. Although there is a strong correlation between the reductions in CO and SMAF, the reduction in SMAF is greater than the reduction in CO. This finding suggests that optimizing cardiac function alone during periods of even moderate levels of increased IAP may be inadequate to normalize SMAF. This lends further support for early abdominal decompression in the treatment of trauma patients with increased IAP.

The relationship of packed cell transfusion to red blood cell deformability in systemic inflammatory response syndrome patients.

RBC deformability (RBCD) is decreased in critically ill patients. This is thought to impede the passage of the RBC through the microcirculation. The cell transit analyzer (CTA) provides an evaluation of RBCD. RBCD was examined in 16 patients admitted to the surgical intensive care unit. CTA analysis was conducted within 24 h of admission to the surgical intensive care unit or as soon as possible thereafter, and then repeated every 72 h. Counts per second (C/s) was the parameter used as an index of RBCD. Patients were classified as Septic/SIRS or nonseptic at the time of each blood collection by standard clinical criteria. There were 34 total specimens, 22 septic/SIRS and 12 nonseptic. The C/s for the SIRS samples (41.7 +/- 3.4 was significantly (p < .05) lower than that of the non-SIRS samples (54.3 +/- 5.3). Seventeen of the Septic/SIRS samples were obtained following blood transfusion. Pearson's test calculated for the C/s and the total number of packed RBC transfusions showed a positive correlation (r = .594) that was statistically significant (p < .02). CTA was also performed on 10 U of banked packed RBC in vitro. Deformability was maintained at a constant level until the very end of the storage period, at which time there was a statistically significant decrease in C/s (p < .0001). These data suggest that packed RBC transfusion is associated with a significant improvement in the abnormally low RBCD seen in critically ill patients. This may be due to replacement of previously rigidified cells by cells with a more normal RBCD.

Rasterstereography-based classification of normal corneas.

PURPOSE: To attempt to classify the topographic patterns identified by rasterstereography in a population with normal corneas. SETTING: Tulane Medical Center Clinic, New Orleans, Louisiana. METHODS: Corneal elevation pictures of 100 eyes of 50 volunteers were taken using the PAR Corneal Topography System. The volunteers had no history of eye injury, disease, or surgery, and none wore contact lenses. Three observers independently assigned the images to one of five subgroups. RESULTS: Five categories were identified: unclassified, regular ridge, irregular ridge, incomplete ridge, and island. There were significant statistical differences in the degree of astigmatism between the irregular ridge and incomplete ridge groups (P = .0419) and between the irregular ridge and island groups (P = .017). CONCLUSION: The topographic patterns identified by rasterstereography in normal corneas can be classified into five distinct groups.

Hemorrhage lowers the threshold for intra-abdominal hypertension-induced pulmonary dysfunction.

BACKGROUND: Intra-abdominal hypertension has been associated with pulmonary and cardiac dysfunctions. We have noted in the clinical scenario of hemorrhagic shock and resuscitation that avoidance of even moderate levels of increased intra-abdominal pressure, using prophylactic decompression, improves outcomes when compared with patients who were decompressed when intra-abdominal pressures went over 20 cm H2O. We hypothesized that prior hemorrhage and resuscitation exacerbates the cardiopulmonary dysfunction associated with intra-abdominal hypertension. METHODS: Ten anesthetized pigs underwent placement of arterial and pulmonary artery catheters and a Silastic intra-abdominal catheter for measuring and manipulating intra-abdominal pressure. Group 1 animals (n = 5) were subjected to increasing intra-abdominal pressures at 10 mm Hg increments up to a level of 40 mm Hg. Group 2 animals (n = 5) were exposed to a severe hemorrhage and resuscitation before the increasing intra-abdominal pressure protocol. RESULTS: Compared with baseline, hemorrhage and resuscitation caused a significant deterioration in cardiac output at intra-abdominal pressures of 10 mm Hg and above. Oxygenation was reduced at 30 and 40 mm Hg. These changes were not seen in group 1 animals. A significant difference was found between groups 1 and 2 in VT, PaCO2, and PaCO2/FIO2 ratio at an intra-abdominal pressure of 20 mm Hg. This difference was not seen at lower or higher pressures. CONCLUSIONS: Prior hemorrhage and resuscitation caused an earlier decline in cardiopulmonary function in the setting of increased intra-abdominal pressure. These data suggest that, when interpreting intra-abdominal pressures, the clinical scenario must be considered. Prior hemorrhage and resuscitation produce the adverse consequences of intra-abdominal hypertension at lower pressures than when intra-abdominal hypertension is the only insult.

Radial and astigmatic keratotomy experience by residents and fellows at a teaching institution.

PURPOSE: To retrospectively study 30 cases of radial and astigmatic keratotomy performed by third-year ophthalmology residents and cornea fellows. SETTING: Tulane University Medical Center, New Orleans, Louisiana. METHODS: Patients were selected based on correction for stable myopia without or with astigmatism. Four or eight radial incisions were made using the Russian (uphill) method. The astigmatic cuts were straight transverse. RESULTS: Uncorrected visual acuity postoperatively was 20/40 or better in 28 eyes (93%). Two patients(visual acuity 20/50 and 20/70) were scheduled for secondary procedures but were lost to follow-up. Complications included three microperforations without sequelae. CONCLUSION: Radial and astigmatic keratotomy to correct myopia or myopia with astigmatism can be safe and effective in the hands of a beginning surgeon.

New technique for studying incision depth in experimental radial keratotomy.

Older techniques of analyzing incision depth in incisional keratotomy consist of serial transverse sections taken at various points along the incision. Information as to shape and depth of the incision are reconstructed from these sections. We describe a new method for studying the incision depth and profile along the entire incision length.

Videokeratographic evaluation of peripheral redeepening in the cadaver eye.

Radial incisions must be deep enough to correct myopia. As currently performed, most surgeons set their diamond blades at a constant depth and do not alter the blade length throughout the procedure. The cornea is not uniformly thick; the central cornea is the thinnest and it thickens toward the periphery. Therefore, an incision of constant depth would be deeper centrally and thinner peripherally. Peripheral redeepening of the cornea would in theory make the incision depth deeper throughout and should increase the effect of radial incisions. We reviewed the literature on this technique and performed radial incisional studies on the human cadaver eye using videokeratography to measure incision depth indirectly. Based on our studies, we believe that peripheral redeepening has no effect on central cornea flattening.

Induction of astigmatism by straight transverse corneal incisions, 45 degrees long, at different clear zones in human cadaver eyes.

BACKGROUND: Two of the major factors affecting the amount of astigmatism correction are the length of the transverse incision and its distance from the center of the cornea. Many nomograms used in clinical practice have been created by varying the length or clear zone diameter of the incisions. A simplification of this situation has been suggested by Thornton, who has theorized that straight transverse incisions, subtending 45 degrees of arc, have equal astigmatic corrective effect at different clear zones. Our study tested Thornton's theory in human donor eyes. METHODS: Ten eyes were tested at four clear zones: 5.0, 6.0, 7.0, and 8.0 mm. Paired straight transverse incisions, subtending an arc of 45 degrees (2.1 to 3.3 mm long), were centered on the 90-degree meridian. Preoperative keratometric readings at the 180- and 90-degree meridians were compared to the postoperative readings; the difference was the total astigmatism induced. We also calculated the coupling ratio. RESULTS: Student's t-tests comparing clear zones 6.0 and 7.0 mm revealed a statistical difference (p = .0085) in total astigmatic induction, greater for the 6.0-millimeter zone. The coupling ratio decreased as the clear zone diameter increased, presumably as a result of diminished flattening effect along the incised meridian. One-way analysis of variance indicated that the groups were different (p = .0001), and that the theory noted above was incorrect. CONCLUSIONS: The effect of transverse incisions subtending the same angular length, drops off dramatically with clear zones larger than 6.0 mm, contrary to the theory of Thornton. This effect may be due to reduction in coupling as the clear zone diameter increases, suggesting that the greatest efficacy is achieved for transverse incisions placed between 5.0- and 6.0-millimeter zones.

Quantitative measurement of wound spreading in radial keratotomy.

BACKGROUND: Many studies of radial keratotomy have been performed, however quantitative laboratory evaluation of the biomechanics of this procedure is still incomplete. Furthermore, most measurements of strain in the past have utilized strip testing, thus destroying the normal physiological structure and water balance of the cornea. METHODS: We report on a membrane inflation method of wound spreading in intact human corneas using the Baribeau Micronscope. RESULTS: We measured a secant elastic modulus of 7.58 x 10(6) N/m2 between 25 and 100 mm Hg. The spreading of radial keratotomy incisions as a function of intraocular pressure showed a maximum spreading of approximately 50 mu at 25 mm Hg at a radius of 3.50 mm from the optical center. A slight increase in spreading was observed in proceeding from a single to four radial incisions. CONCLUSIONS: Quantitative measurement of wound spreading is an important parameter of radial keratotomy and can provide important information regarding opposing theories of the biomechanics of this operation.

Intracorneal hemorrhage secondary to aphakic contact lens wear.

Two cases of intracorneal hemorrhage developing as a complication of aphakic contact lens use are reported. Patient 1 had a penetrating keratoplasty to restore vision and therefore the histologic examination could be performed on the corneal button. In patient 2 the contact lens use was discontinued with partial resolution of the intracorneal hemorrhage and the patient then underwent a secondary intraocular lens implantation with good visual results.