Bile duct injury following laparoscopic cholecystectomy: a cause for continued concern.

Previous reports suggest that bile duct injuries sustained during laparoscopic cholecystectomy (lap chole) are frequently severe and related to cautery and high clip ligation. We performed a review of patients who sustained bile duct injury from lap chole since 1990 and assessed time to injury recognition, time to referral, Bismuth classification, initial and subsequent repairs, rate of recurrence, and length of follow-up. Seventy-four patients [median age 44 years, 58 of 74 female (78%)] were referred with a bile duct injury after lap chole. The level of injury was evenly divided between the bile duct bifurcation and the common hepatic duct: Bismuth III, IV, and V (40 of 74, 54%) versus Bismuth I and II (34 of 74, 46%). Concomitant hepatic arterial injury was identified in nine (12%) patients. Patients referred early after bile duct injury and requiring operative intervention underwent hepaticojejunostomy at a median of 2 days after referral. After surgical reconstruction at our center there has been an overall success rate of 89 per cent with no need for reintervention. Six (10%) of these patients have required one additional balloon dilatation at a mean follow-up of >24 months. One (2%) patient underwent biliary-enteric revision in follow-up. In patients with bile duct injury, stricture repair without delay was successful in the majority of patients treated in this series. Only one of 64 patients reconstructed at our center has required reoperation; six others have required a single balloon dilatation with subsequent good or excellent results. The majority of patients treated with operative repair at an experienced center can expect good long-term results with rare need for reintervention.

Hepatic cryoablation-induced acute lung injury: histopathologic findings.

We have previously shown that hepatic cryoablation (cryo), but not partial hepatectomy, induces a systemic inflammatory response, with distant organ injury and overproduction of NF-kappaB-dependent cytokines. Serum tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-2 (MIP-2) levels are markedly increased 1 h and beyond after cryo compared with partial hepatectomy where no elevation occurs. NF-kappaB activation (by electrophoretic mobility shift assay) is strikingly increased in the noncryo liver (but not in the lung) at 30 min and in both the liver and lung tissue 1 h after cryo, returning to the baseline by 2 h and beyond. The current study investigated the histopathologic changes associated with cryoablation-induced acute lung injury. Animals underwent 35% hepatic resection or a similar volume hepatic cryo and were sacrificed at 1, 2, 6, and 24 h. Pulmonary histologic features were assessed using hematoxylin and eosin and immunoperoxidase staining with a macrophage-specific antibody (anti-lysozyme, 1:200 dilution, Dako, Carpinteria, CA). The following features were graded semiquantitatively (0-3): perivascular lymphoid cuffs, airspace edema and hemorrhage, margination of neutrophils within pulmonary vasculature, and the presence of macrophages with foamy cytoplasm in the pulmonary interstitium. Hepatic resection (n = 21) resulted in slight perivascular edema at 1, 2, 6, and 24 h post-resection, but there were no other significant changes. Pulmonary findings after hepatic cryo (n = 22) included prominent perivascular lymphoid cuffs 1 and 2 h following hepatic injury that were not present at any other time point (P 0.01). Marginating PMNs and foamy macrophages were more common after cryo at all time points (P<0.05, cryo vs resection). Severe lung injury, as evidenced by airspace edema and parenchymal hemorrhage, was present in four of six (67%) animals at 24 h (P 0.03). In follow-up studies immediate resection (n = 15) of the cryo-treated liver prior to thawing prevented the pulmonary changes. The findings of pulmonary perivascular interstitial macrophages 2 h following hepatic cryo suggests that hepatic cytokine production may induce downstream recruitment of pulmonary macrophages, which may contribute to subsequent severe lung injury. This study suggests that a soluble mediator from direct liver injury leads to neutrophilic lung inflammation and this is associated with the thawing phase of cryoablation.

In vitro collection and posttransfusion engraftment characteristics of MNCs obtained by using a new separator for autologous PBPC transplantation.

BACKGROUND: A clinical study was performed to evaluate the peripheral blood progenitor cell (PBPC) collection, transfusion, and engraftment characteristics associated with use of a blood cell separator (Amicus, Baxter Healthcare). STUDY DESIGN AND METHODS: Oncology patients (n = 31) scheduled for an autologous PBPC transplant following myeloablative therapy were studied. PBPCs were mobilized by a variety of chemotherapeutic regimens and the use of G-CSF. As no prior studies evaluated whether PBPCs collected on the Amicus separator would be viable after transfusion, to ensure patient safety, PBPCs were first collected on another cell separator (CS-3000 Plus, Baxter) and stored as backup. The day after the CS-3000 Plus collections were completed, PBPC collections intended for transfusion were performed using the Amicus instrument. For each transplant, >2.5 x 10(6) CD34+ PBPCs per kg of body weight were transfused. RESULTS: Clinical data collected on the donors immediately before and after PBPC collection with the Amicus device were comparable to donor data similarly obtained for the CS-3000 Plus collections. While the number of CD34+ cells and the RBC volume in the collected products were equivalent for the two devices, the platelet content of the Amicus collections was significantly lower than that of the CS-3000 Plus collections (4.35 x 10(10) platelets/bag vs. 6.61 x 10(10) platelets/bag, p<0.05). Collection efficiencies for CD34+ cells were 64 +/- 23 percent for the Amicus device and 43 +/- 14 percent for the CS-3000 Plus device (p<0.05). The mean time to engraftment for cells collected via the Amicus device was 8.7 +/- 0.7 days for >500 PMNs per microL and 9.7 +/- 1.5 days to attain a platelet count of >20,000 per microL-equivalent to data in the literature. No CS-3000 Plus backup cells were transfused and no serious adverse events attributable to the Amicus device were encountered. CONCLUSIONS: The mean Amicus CD34+ cell collection efficiency was better (p<0.05) than that of the CS-3000 Plus collection. Short-term engraftment was durable. The PBPCs collected with the Amicus separator are safe and effective for use for autologous transplant patients requiring PBPC rescue from high-dose myeloablative chemotherapy.

Technical advances toward interactive image-guided laparoscopic surgery.

BACKGROUND: Laparoscopic surgery uses real-time video to display the operative field. Interactive image-guided surgery (IIGS) is the real-time display of surgical instrument location on corresponding computed tomography (CT) scans or magnetic resonance images (MRI). We hypothesize that laparoscopic IIGS technologies can be combined to offer guidance for general surgery and, in particular, hepatic procedures. Tumor information determined from CT imaging can be overlayed onto laparoscopic video imaging to allow more precise resection or ablation. METHODS: We mapped three-dimensional (3D) physical space to 2D laparoscopic video space using a common mathematical formula. Inherent distortions present in the video images were quantified and then corrected to determine their effect on this 3D to 2D mapping. RESULTS: Errors in mapping 3D physical space to 2D video image space ranged from 0.65 to 2.75 mm. CONCLUSIONS: Laparoscopic IIGS allows accurate (<3.0 mm) confirmation of 3D physical space points on video images. This in combination with accurately tracked instruments and an appropriate display may facilitate enhanced image guidance during laparoscopy.

Hepatic cryoablation-induced acute lung injury: pulmonary hemodynamic and permeability effects in a sheep model.

HYPOTHESIS: Hepatic cryoablation of 30% to 35% or more of liver parenchyma in a sheep model results in eicosanoid and nuclear factor-kappaB (NF-kappaB)-mediated changes in pulmonary hemodynamics and lung permeability. SETTING: Laboratory. INTERVENTIONS: At initial thoracotomy, catheters were placed in the main pulmonary artery, left atrium, right carotid artery, and efferent duct of the caudal mediastinal lymph node for subsequent monitoring in adult sheep. After a 1- to 2-week period of recovery, animals underwent laparotomy and left-lobe cryoablation (approximately 35% by volume) with subsequent awake monitoring and on postoperative days 1 to 3. MAIN OUTCOME MEASURES: Cryoablation-induced lung permeability and hemodynamic changes were compared with baseline values in sheep that underwent instrumentation. Similarly handled sheep underwent resection of a similar volume of hepatic parenchyma or had pulmonary artery pressure increases induced by mechanical left atrial obstruction. Activation of NF-kappaB was assessed with electrophoretic mobility shift assay, and serum thromboxane levels were measured with mass spectroscopy. RESULTS: Cryoablation resulted in acutely increased mean pulmonary (20 to 35 cm water) and systemic pressures, which returned to baseline at 24 hours with no change in cardiac output. Serum thromboxane levels increased 30 minutes after cryoablation (9-fold) and returned to baseline at 24 hours. Activation of NF-kappaB was present in liver and lung tissue by 30 minutes after cryoablation. Lung lymph-plasma protein clearance markedly exceeded the expected increase from pulmonary pressures alone, and increased lymph-plasma protein ratio persisted after pulmonary artery pressures normalized. Similar changes were not associated with 35% hepatic resection. CONCLUSIONS: This study demonstrates that 35% hepatic cryoablation results in an acute but transient increase in pulmonary artery pressure that may be mediated by increased thromboxane levels. Increases in pulmonary capillary permeability are not accounted for by pressure changes alone, and may be a result of NF-kappaB-mediated inflammatory mechanisms. These data show that cryosurgery causes pathophysiological changes similar to those observed with endotoxin and other systemic inflammatory stimuli.

The incidence of splenectomy is decreasing: lessons learned from trauma experience.

Over the past decade, splenic preservation has become a well-reported and accepted principle in trauma management. The reasons for splenic preservation may have influenced nontraumatic surgical management as well. To investigate the changing incidence and indications for splenectomy, we conducted a 10-year review of all splenectomies at our institution. During this time, between January 1, 1986, and December 31, 1995, 896 patients underwent splenectomy. Hospital charts and records were examined to determine the etiology and incidence of splenectomy. Indications were classified as: 1) trauma, i.e., performed for blunt or penetrating injury; 2) hematologic malignancy, i.e., therapy or staging of underlying leukemia, Hodgkin's lymphoma, or non-Hodgkin's lymphoma; 3) cytopenia, i.e., treatment of thrombocytopenia, anemia, or leukopenia; 4) iatrogenic, i.e., injury during another procedure; 5) incidental, i.e., required for adjacent organ resection; 6) portal hypertension, i.e., left-sided portal hypertension or during shunting procedure; 7) diagnostic, i.e., uncertainty excluding hematologic malignancy; or 8) other, i.e., miscellaneous indications. Trauma accounted for 41.5 per cent of all splenectomies during this time period, hematologic malignancy 15.4 per cent, cytopenia 15.6 per cent, incidental 12.3 per cent, iatrogenic 8.1 per cent, portal hypertension 2.3 per cent, diagnostic 2.0 per cent, and other 2.7 per cent. Comparing the first and second 5-year time periods, the following increases/decreases in average annual incidence were noted: splenectomy for all indications, -36.9 per cent; trauma, -32.9 per cent; hematologic malignancy, -51.4 per cent; cytopenia, 35.1 per cent; incidental, -35.9 per cent; iatrogenic, -30.2 per cent; diagnostic, +4.9 per cent, and other, -57 per cent. Traumatic injury to the spleen remains the most common indication for splenectomy, but the incidence has decreased dramatically over the past 10 years. Splenectomies for treatment of hematologic malignancies and cytopenia, as well as incidental and iatrogenic splenectomies, have also decreased significantly. Only the incidence of diagnostic splenectomy has remained stable. Although initiated within the field of trauma, the advantages of splenic preservation now appear to be well recognized beyond that field.

Hepatic cryoablation, but not radiofrequency ablation, results in lung inflammation.

OBJECTIVE: To compare the effects of 35% hepatic cryoablation with a similar degree of radiofrequency ablation (RFA) on lung inflammation, nuclear factor kappaB (NF-kappaB) activation, and production of NF-kappaB dependent cytokines. SUMMARY BACKGROUND DATA: Multisystem injury, including acute lung injury, is a severe complication associated with hepatic cryoablation of 30% to 35% or more of liver parenchyma, but this complication has not been reported with RFA. METHODS: Sprague-Dawley rats underwent 35% hepatic cryoablation or RFA and were killed at 1, 2, and 6 hours. Liver and lung tissue were freeze-clamped for measurement of NF-kappaB activation, which was detected by electrophoretic mobility shift assay. Serum concentrations of tumor necrosis factor alpha and macrophage inflammatory protein 2 were measured by enzyme-linked immunosorbent assay. Histologic studies of pulmonary tissue and electron microscopy of ablated liver tissue were compared among treatment groups. RESULTS: Histologic lung sections after cryoablation showed multiple foci of perivenular inflammation, with activated lymphocytes, foamy macrophages, and neutrophils. In animals undergoing RFA, inflammatory foci were not present. NF-kappaB activation was detected at 1 hour in both liver and lung tissue samples of animals undergoing cryoablation but not after RFA, and serum cytokine levels were significantly elevated in cryoablation versus RFA animals. Electron microscopy of cryoablation-treated liver tissue demonstrated disruption of the hepatocyte plasma membrane with extension of intact hepatocyte organelles into the space of Disse; RFA-treated liver tissue demonstrated coagulative destruction of hepatocyte organelles within an intact plasma membrane. To determine the stimulus for systemic inflammation, rats treated with cryoablation had either immediate resection of the ablated segment or delayed resection after a 15-minute thawing interval. Immediate resection of the cryoablated liver tissue prevented NF-kappaB activation and lung injury; however, pulmonary inflammatory changes were present when as little as a 15-minute thaw interval preceded hepatic resection. CONCLUSIONS: Hepatic cryoablation, but not RFA, induces NF-kappaB activation in the nonablated liver and lung and is associated with acute lung injury. Lung inflammation is associated with the thawing phase of cryoablation and may be related to soluble mediator(s) released from the cryoablated tissue. These findings correlate the clinical observation of an increased incidence of multisystem injury, including adult respiratory distress syndrome (ARDS), after cryoablation but not RFA.

Isolation and flow cytometric analysis of T-cell-depleted CD34+ PBPCs.

BACKGROUND: To extend allogeneic HPC transplantation to a greater range of patients, the use of partially matched related donors is under development. Because of the inherently higher degree of histoincompatibility in such transplants, there is increased risk of GVHD as well as of graft failure. Ex vivo depletion of donor-derived T-lymphocytes from PBPCs is one of the most effective methods of preventing GVHD. Thus far, individual centers have used custom-developed procedures to deplete the graft of T cells that are responsible for alloreactivity, often employing relatively impure, nonstandardized reagents such as soybean agglutinin and complement. In addition, with improved methods of T-cell depletion, it has been difficult to accurately assess the number of T cells remaining. Because different centers have used different protocols to assay T cells, it has been difficult to reproduce and validate the results between institutions, and this has limited direct comparison of data between centers. STUDY DESIGN AND METHODS: A standardized approach for T-cell depletion was developed by using a Good Manufacturing Practice-manufactured magnetic cell separator (Isolex 300i, Nexell Therapeutics) and commercially available OKT3 antibody. T-cell depletion was performed on PBPCs from six haploidentical donors. RESULTS: CD34+ cell recovery was 47 percent (range, 31-63%) with a median purity of 94 percent (range, 75-99%) and median T-cell log depletion of 4.72 (range, 3.90-5.83). Because this high degree of depletion makes it challenging to accurately quantitate the remaining T cells, two highly sensitive flow cytometric protocols were developed, each of which accurately detects T cells with a sensitivity of 2 per 10,000 (0.02%). The purified CD34+ cells administered to the patients (dose range, 6.13-13.50 x 10(6)/kg) provided rapid neutrophil and platelet engraftment. CONCLUSION: With the Isolex 300i and a MoAb directed against T cells, a high degree of T-cell depletion is obtained. Sensitive, accurate, and reproducible assays have now been developed for T-cell enumeration in these highly purified cell populations.

Acute lung injury after hepatic cryoablation: correlation with NF-kappa B activation and cytokine production.

BACKGROUND: Previous clinical reports have documented multisystem organ injury after hepatic cryoablation. We hypothesized that hepatic cryosurgery, but not partial hepatectomy, induces a systemic inflammatory response characterized by distant organ injury and overproduction of nuclear factor kappa B (NF-kappa B)-dependent, proinflammatory cytokines. METHODS: In this study, rats underwent either cryoablation of 35% of liver parenchyma or a similar resection of left hepatic tissue. Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels and NF-kappa B activation were assessed by electrophoretic mobility shift assay at 30 minutes 1, 2, 6, and 24 hours after either procedure. RESULTS: Cryoablation of 35% of liver (n = 22 rats) resulted in lung injury and a 45% mortality rate within 24 hours of surgery, whereas 7% treated with 35% hepatectomy (n = 15 rats) died during the 24 hours after surgery (P < .05, cryoablation vs hepatectomy). Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels were markedly increased in rats (n = 10 rats) 1 hour after hepatic cryoablation compared with rats that underwent partial hepatectomy (P < .005). We evaluated NF-kappa B activation by electrophoretic mobility shift assay in nuclear extracts of liver and lung after cryosurgery and found that NF-kappa B activation was strikingly increased in the liver but not the lung at 30 minutes and in both organs 1 hour after cryosurgery, and returned to baseline in both organs by 2 hours. In rats undergoing 35% hepatectomy, no increase in NF-kappa B activation was detected in nuclear extracts of either liver or lung at any time point. CONCLUSIONS: These data show that hepatic cryosurgery results in systemic inflammation with activation of NF-kappa B and increased production of NF-kappa B-dependent cytokines. Our data suggest that lung injury and death in this animal model is mediated by an exaggerated inflammatory response to cryosurgery.

Acute pancreatitis after cardiac transplantation and other cardiac procedures: case-control analysis in 24,631 patients.

Previous series have identified an increased risk of developing acute postoperative pancreatitis in heart transplant recipients and other cardiac surgical patients, and some suggest that mortality is significantly increased when pancreatitis occurs in the transplant setting. We conducted a retrospective case-control analysis of adult patients undergoing orthotopic heart transplant or other cardiac procedures from April 1985 through June 1996 at our medical center. Specific risk factors for outcome were assessed including low cardiac output, intra-aortic balloon pump usage, exogenous calcium repletion, immunosuppression, cytomegalovirus infection, cholelithiasis, prior pancreatitis, and Acute Physiology and Chronic Health Evaluation (APACHE) II scores. There was a 30-fold increase in the incidence of pancreatitis in the heart transplant group [12 of 394 (3%) vs 27 of 24,237 (0.1%); P < 0.01]. Compared with the nontransplant cardiopulmonary bypass patients, the transplant patients experienced a statistically significant increased incidence of immunosuppression and three or more risk factors. Transplant patients with pancreatitis demonstrated a significant increase in APACHE II scores and the incidence of three or more risk factors compared with their transplant control group. Patients undergoing nontransplant cardiac procedures and developing pancreatitis had significantly increased cross-clamp times, incidence of low cardiac output, APACHE II scores, and incidence of three or more risk factors compared with their nontransplant cohort. In conclusion, there is a significant increase in the incidence of pancreatitis after orthotopic heart transplant compared with other cardiac procedures. Analysis demonstrates the additive effect of multiple individual risk factors. Immunosuppression confers significant additional risk for pancreatitis in the orthotopic heart transplant patient.

Transcatheter arterial chemoembolization as primary treatment for hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) in Western populations has historically been associated with poor survival. METHODS: In this study, we conducted a 7-year retrospective analysis of patients with HCC undergoing transcatheter arterial chemoembolization (TACE) at our institution and examined demographics, outcomes, and complications. RESULTS: During the period of study, 39 patients (25 male [64%], mean age 58 [range 17 to 86]) underwent a total of 78 chemoembolization treatments. During the same time period, an additional 31 patients received supportive care only. The majority of patients had late stage disease (American Joint Committee on Cancer stage III, IVa, or IVb) with no statistical difference noted between the two groups (P = 0.2). However, patients receiving supportive care only had significantly worse hepatic dysfunction by Child's classification (P = 0.005). Twenty-nine patients (74%) had documented cirrhosis, with hepatitis C being the most common cause in 11 of 29 (38%). In patients undergoing TACE, overall actuarial survival was 35%, 20%, and 11% at 1, 2, and 3 years with a median survival of 9.2 months, significantly improved over the group receiving supportive care only (P < 0.0001). Median survival for the group receiving supportive care was less than 3 months. Neither age nor stage had a significant impact on survival. The most common complications of TACE included transient nausea, abdominal pain, vomiting, and fever. CONCLUSIONS: TACE is a safe and effective therapeutic option for selected patients with HCC not amenable to surgical intervention.

Image-guided surgery: preliminary feasibility studies of frameless stereotactic liver surgery.

BACKGROUND: Liver surgery can be difficult because there are few external landmarks defining hepatic anatomy and because the liver has significant vascularity. Although preoperative tomographic imaging (computed tomography or magnetic resonance imaging) provides essential anatomical information for operative planning, at present it cannot be used actively for precise localization during surgery. Interactive image-guided surgery involves the simultaneous real-time display of intraoperative instrument location on preoperative images (computed or positron-emission tomography or magnetic resonance imaging). Interactive image-guided surgery has been described for tumor localization in the brain (frameless stereotactic surgery) and allows for interactive use of preoperative images during resections or biopsies. HYPOTHESIS: The application of interactive image-guided surgery (IIGS) is feasible for hepatic procedures from a biomedical engineering standpoint. METHODS: We developed an interactive image-guided surgery system for liver surgery and tested a porcine liver model for tracking liver motion during insufflation; liver motion during respiration in open procedures in patients undergoing hepatic resection; and tracking accuracy of general surgical instruments, including a laparoscope and an ultrasound probe. RESULTS: Liver motion due to insufflation can be quantified; average motion was 2.5+/-1.4 mm. Average total liver motion secondary to respiration in patients was 10.8 +/-2.5 mm. Instruments of varying lengths, including a laparoscope, can be tracked to accuracies ranging from 1.4 to 2.1 mm within a 27-m3 (3 X 3 X 3-m) space. CONCLUSION: Interactive image-guided surgery appears to be feasible for open and laparoscopic hepatic procedures and may enhance future operative localization.

Antiperistaltic Roux-en-Y biliary-enteric bypass after bile duct injury: a technical error in reconstruction.

Bilioenteric reconstruction using a Roux limb of jejunum is a well-established surgical option for the reconstruction of the proximal bile duct. Previous studies discussing short- and long-term complications of biliary-enteric anastomosis have focused on technical aspects, such as the use of anastomotic stenting or the level of the biliary tree used. We report two cases of previously unreported complications after hepaticojejunostomy that resulted from a technical error in constructing the Roux limb. Within a 3-month period, two patients were referred to our institution with recurrent cholangitis after biliary reconstruction for injuries sustained during laparoscopic cholecystectomy. Reexploration disclosed major technical flaws in the construction of the Roux limb used for biliary drainage. Antiperistaltic limbs had been constructed in both patients: one from the distal ileum and one from the conventional location in the jejunum. In both cases, isoperistaltic reconstruction of the Roux limbs resolved the recurrent cholangitis. Cholangitis after biliary-enteric bypass can arise from a variety of etiologies and lead to anastomotic narrowing or ineffective drainage of the biliary tree. Review of the literature failed to disclose reports of technically flawed Roux limb construction as a cause of cholangitis. We present these cases to highlight the devastating consequences of antiperistaltic construction of the Roux limb. We hope that by publishing the role of this avoidable error in recurrent cholangitis after biliary-enteric bypass we may help prevent its future occurrence.

Hepatocellular carcinoma outcomes based on indicated treatment strategy.

Hepatocellular carcinoma (HCC) in Western populations historically has been associated with poor survival. In this study, we conducted a 7-year retrospective analysis of patients evaluated at our institution with HCC to determine the effects of newer treatment strategies on outcome. During the period of study, 117 patients [86 (74%) male; mean age, 59 years (range, 16-85)] were evaluated with treatment as follows: surgical resection in 22 (19%), chemoembolization with or without systemic chemotherapy in 40 (35%), systemic treatment alone in 16 (13%), orthotopic liver transplantation in 8 (7%), and supportive care only in 31 (26%). Sixty-nine patients (59%) had documented cirrhosis, with hepatitis C being the most common cause in 27 of 69 (39%). In patients receiving no treatment, median survival was just under 3 months, with only two 1-year survivors. Patients with orthotopic liver transplantation had 1-, 2-, and 3-year survival rates of 87, 87, and 58 per cent compared with 69, 52, and 43 per cent in surgically resected patients. Survival after chemoembolization was 35, 20, and 11 per cent at 1, 2, and 3 years, whereas survival after systemic chemotherapy was 30 and 15 per cent at 1 and 2 years, respectively. One-year survival was improved in noncirrhotic patients compared with cirrhotics (47% vs 29%; P < 0.05) but was no different in patients younger than 55 years compared with older patients (38% vs 38%). When possible, surgical treatment strategies offer superior survival.

Establishment and characterization of primary gallbladder epithelial cell cultures in the prairie dog.

BACKGROUND: The prairie dog has become the established animal gallstone model. This species has a unique propensity to form cholesterol gallstones in response to dietary manipulations. The development of a reliable gallbladder cell culture technique is critical for understanding pathogenic mechanisms of gallstone formation. MATERIALS AND METHODS: Prairie dogs underwent laparotomy and cholecystectomy, followed by initiation of cell cultures. [3H]Thymidine incorporation was used to assess cell growth, and cell lines were assessed using routine histochemical and immunohistochemical staining. RESULTS: Cell yields from prairie dog gallbladders were 4-8 x 10(6) viable cells per animal with viability ranging from 80 to 95%. When plated at 5 x 10(5) cells/cm2, cell clusters, visible within 24 h, coalesced into confluent monolayers within 3-5 days. Cultures remained viable for 6-8 weeks and could be passed for three to four subcultures. Immunohistochemical staining demonstrated a high degree of epithelial purity with immunopositivity for AE1/AE3, and cytokeratin, with no vimentin positivity (mesenchymal antigen). Intracytoplasmic vacuoles demonstrated positive staining for Alcian blue, periodic acid-Schiff, and mucicarmine and an anti-gallbladder mucin antibody confirmed the presence of the glycoprotein mucin. CONCLUSIONS: This study demonstrates a reliable method for initiation and maintenance of prairie dog gallbladder epithelial cell cultures with a high degree of purity. This technique should allow further studies into the pathogenesis of cholesterol gallstones in this model.

Surgical clips: a cause of late recurrent gallstones.

The formation of gallstones around surgical clips after cholecystectomy is a rare complication, with only seven reported cases in the English literature since its initial description in 1979. Three other cases report clip migration into the common bile duct and obstruction. We report a recent experience with "clip cholelithiasis." A 78-year-old female, 16 years following cholecystectomy, presented with a several-month history of colicky abdominal pain worsened by meals, and a 1 week history of jaundice, anorexia, nausea, and vomiting. An abdominal ultrasound demonstrated dilatation of the biliary tree without visible choledocholithiasis. Endoscopic retrograde cholangiopancreatography demonstrated a 1.5-cm radiolucent stone in the common bile duct containing a central surgical clip. She was successfully treated with endoscopic sphincterotomy and stone retrieval. The first report of clip cholelithiasis occurred in 1979. Six additional cases have been reported as well as three cases of clip migration without stone formation into the common bile duct. The incidence of clip cholelithiasis may increase in frequency with the increased use of metallic clips during laparoscopic cholecystectomy. The occurrence of cholelithiasis around inert metals is rare and may be prevented using absorbable clips; however, stone formation is also reported around absorbable materials.

A quantitative system to evaluate diabetic retinopathy from fundus photographs.

PURPOSE: To evaluate a quantitative system to measure the early lesions of diabetic retinopathy seen in stereoscopic fundus photographs. METHODS: Using a quantitative classification system, photographs of 4657 eyes (7 stereo pairs of 35-mm slides per eye) were scored for 16 diabetic lesions. A single severity level (identical to the ETDRS Interim Scale) was calculated for each eye. The reliability of this technique, and its reproducibility by independent examiners, was evaluated for individual lesions and severity levels using percent agreement, kappa, and weighted kappa statistics. RESULTS: This quantitative technique demonstrated an "almost perfect" agreement (weighted kappa > or = 0.810) on all but one lesion by independent observers. For the severity levels, there was a 95.7% perfect agreement (kappa = 0.9428). The reproducibility of agreement over time was "almost perfect" on all but four lesions; with 88% perfect agreement (kappa = 0.8394) for severity levels. CONCLUSIONS: When used to evaluate the early lesions of diabetic retinopathy, the Vanderbilt Classification System is highly reliable between graders and over time. This system can gather quantitative data and evaluate incremental changes in an accurate, reproducible manner.