Biomedical subjects

J Debelak

Publications and source records attributed to J Debelak.

6 recordsLinked to original sources

PubMed2001

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.

Adolescent↗

PubMed2000

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.

Equipment Design↗

PubMed2000

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.

Adolescent↗

PubMed2000

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.

Adult↗

PubMed2000

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.

Humans↗

PubMed1999

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.

APACHE↗