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Biomedical subjects

R C Lim

Publications and source records attributed to R C Lim.

At least 19 recordsLinked to original sources
PubMed1998

Biliary complications of reduced-organ liver transplantation.

Reduced-organ liver transplantation for children is effective in lowering pretransplantation morbidity and mortality. Improvements in surgical technique have reduced vascular complications; however, biliary complications continue to account for significant posttransplantation morbidity. This investigation chronicles the incidence and type of biliary complications encountered with reduced-organ liver transplantation. Retrospective review of reduced-organ liver recipients over a 59-month period was performed, and biliary complications were classified as (1) missed biliary radicle, (2) anastomotic leak requiring revision, and (3) biliary stricture. From July 1992 to May 1997, 42 children received reduced-organ grafts: 32 living-donor, 8 cadaveric-reduced, 1 split-liver, and 1 auxiliary orthotopic liver transplant. Of the 42 grafts, 41 were Couinaud segments II/III and 1 was segments II/III/IV. Ten biliary complications were identified in 9 recipients (24%). Biliary complications included parenchymal radicle leaks, 5 (50%); biliary strictures, 3 (30%); and anastomotic leaks, 2 (20%). Although technical advances have reduced the incidence of biliary complications secondary to organ ischemia, parenchymal radicle leaks continue to be a source of morbidity for reduced-organ recipients. Planned exploration on posttransplantation day 7 was performed on the most recent 26 of the 42 total reduced-organ procedures as a mechanism to identify and treat early technical complications. Planned exploration as a routine component of reduced-organ transplantation has yielded a 15% incidence of discovered parenchymal leaks and a 5% incidence of discovered anastomotic leaks. This series underscores the necessity for improved anatomical studies to correctly identify duct territories and the development of accurate noninvasive methods to assess the biliary system preoperatively and intraoperatively in the application of reduced-organ liver transplantation.

Biliary Tract Diseases↗
PubMed1996

Failure patterns of cryopreserved vein grafts in liver transplantation.

Reports of early success with cryopreserved saphenous veins (CSV) as arterial conduits led us to develop cryopreserved iliac veins (CIV) as interposition grafts for portal vein reconstruction in living-related liver transplantation (LRLT). Despite encouraging short-term results, retrospective analysis of long-term cryopreserved vein graft performance in LRLT at our institution has revealed a high rate of late graft failures. Between July 1992 and JUly 1994, interposition grafts (CIV for portal vein interposition n=4, CSV for portal vein interposition n=3, and CSV for hepatic artery interposition n=2) were utilized in 7 LRLT. (Two transplanted organs had both CIV and CSV grafts.) Recipients included 5 children and two small adults (median: 3.5 years, range: 0.5--59 years). Posttransplant follow-up in excess of 36 months revealed portal vein (PV) and hepatic artery (HA) complications of cryopreserved grafts in each patient. PV complications included aneurysm (n=4) diagnosed at 28, 24, 18, and 1.5 mo, stricture (n=1) diagnosed at 11 mo, and thrombosis (n=1) diagnosed at 18 mo posttransplantation. All portal vein complications have been managed without retransplantation, but one (PV thrombosis) necessitated surgical shunt therapy. Each CSV hepatic artery interposition graft has been complicated by thrombosis (diagnosed at 11 days and 24 mo posttransplant) necessitating retransplantation. Based on these observations, we have adopted alternative strategies for HA and PV reconstruction. At present, 11 LRLT have been performed without cryopreserved vein conduits over 17 mo with no vascular complications. While this study does not permit statistical analysis, these results discourage the use cryopreserved iliac veins for portal interposition and cryopreserved saphenous veins for arterial interposition in liver transplantation.

Adolescent↗
PubMed1996

Surgical and anesthetic management of patients undergoing major hepatectomy using total vascular exclusion.

Total vascular exclusion (TVE) of the liver is accomplished by complete occlusion of inflow and outflow of the liver during hepatectomy. It affords the opportunity for bloodless, anatomically precise parenchymal transection but has not been widely used in this country. TVE should make it possible to treat large or unfavorably located lesions safely. To evaluate the benefit of this modality, we have examined the results of TVE in 49 major resections. Forty-nine patients with liver tumors (mean age, 50 +/- 17 years; range 3 to 75 years) were treated by the authors over 5 years with a mean age of 50 +/- 17 years (range 3-75). Thirty-five (71%) patients were females and 38 (78%) had malignant tumors (hepatocellular CA n = 15, liver metastases n = 20, other n = 3), whereas 11 (22%) had benign tumors (hemangiomas n = 7 other n = 4). Six (12%) had histological cirrhosis but normal liver function test results. Twenty two (45%) had previous surgery. Forty-seven (96%) underwent total or extended lobectomies. Two patients had segmental resection of benign tumors (one in segment 4 and one in segment 8). Mean surgical time was 4.7 hours (2.5-8.3 hours) and mean red blood cell requirement was 2.2 U (0 to 11). Twenty-two (45%) procedures were performed without transfusions. Hospital mortality rates were 0%. The mean postoperative hospital duration was 11 days (5 to 41 years). Complications occurred in 18 (36%), requiring reoperation in 1 case for wound debridement and in another for lysis of postoperative adhesions. Hepatic insufficiency occurred transiently in 2 patients with prolongation of protime and cholestasis and resolved within 4 days in 1 patient and 10 days in the other (with cirrhosis). The perception of hepatic resection as a prohibitive undertaking with high mortality rate may limit the use of resection in patients who might benefit from this modality. Our data document the effectiveness and safety of major hepatectomy even in cirrhotic patients using TVE. Expanded use of TVE and other advances in liver surgery should be considered to decrease the morbidity rate of resection and make the benefits of this therapy more widely available.

Adult↗
PubMed1996

Functional analysis of grafts from living donors. Implications for the treatment of older recipients.

OBJECTIVE: Living-related liver transplantation (LRLT) has established efficacy in children. In a larger recipient, LRLT requires the use of a small graft because of limits on the donor hepatectomy. SUMMARY BACKGROUND DATA: The minimum graft weight required for successful transplantation has not been well established, although a characteristic pattern of graft dysfunction has been observed in our patients who receive small grafts. The authors present a clinicopathologic study of small liver grafts obtained from living donors. METHODS: Clinical and histologic data were reviewed for 25 patients receiving LRLT. In five older recipients (small group), the graft represented 50% or less of expected liver weight, whereas in 20 others (large group), the graft represented at least 60% of expected liver weight. A retrospective analysis of graft function was conducted by analyzing clinical parameters and histology. RESULTS: In the small group, 2 of 5 grafts (40%) were lost due to poor function, leading to one patient death (20% mortality), whereas in the large group, 2 of 20 grafts (10%) were lost due to arterial thrombosis without patient mortality. Early ischemic damage related to transplant was comparable with aspartate aminotransferase 203 +/- 23 (small group) and 290 +/- 120 (large group) at 24 hours (p = not significant). Early function was significantly decreased in the small group, with prothrombin time 18.2 +/- 2.2 seconds versus 14.8 +/- 1.6 seconds (large group) on day 3 (p = 0.034). All small group patients developed cholestasis with significantly increased total bilirubin levels at day 7 (16 +/- 5.2 mg% vs. 3.7 +/- 2.7 mg%; p = 0.021) and day 14 (12.0 +/- 7.4 vs. 1.8 +/- 0.7; p = 0.021) compared with the large group. Protocol biopsies in the small group revealed a diffuse ischemic pattern with cellular ballooning on day 7, which progressed to cholestasis in subsequent biopsies. Large group biopsies showed minimal ischemic changes. Three small group patients recovered with normal liver function by 12 weeks. CONCLUSIONS: Clinical recovery after a small-for-size transplant is characterized by significant functional impairment associated with paradoxical histologic changes typical of ischemia. These changes apparently are due to graft injury, which can only be the result of small graft size. These findings have significant implications for the extension of LRLT to adults.

Adolescent↗
PubMed1995

Efficacy of a fibrin hemostatic bandage in controlling hemorrhage from experimental arterial injuries.

OBJECTIVE: To determine if a pressure dressing containing fibrinogen and thrombin could provide more effective control of arterial hemorrhage than a pressure dressing alone in an animal model of arterial injury. DESIGN: Randomized acute (nonsurvival) experiment in swine. SETTING: Federal biomedical research institute. ANIMALS: Six anesthetized Yorkshire swine. INTERVENTIONS: Uncontrolled arterial hemorrhage was induced in anesthetized swine by creating femoral artery lacerations. Hemorrhage was controlled by a gauze bandage containing fibrinogen and thrombin, applied with 1 minute of 3.5-kg pressure. The dressings were left in place for 1 hour after the pressure was removed. The contralateral limbs received identical treatment with plain gauze dressings. MAIN OUTCOME MEASURES: Total blood loss, mean arterial pressure, and mortality were measured after 1 hour. RESULTS: After 1 hour, blood loss in the fibrin bandage group was 123 +/- 48 mL, compared with 734 +/- 134 mL in the control group (P = .0022). In the group treated with the fibrin bandages, there was no significant decrease in the mean arterial pressure after arterial laceration. In contrast, there was a decrease of 30 mm Hg in the group treated with gauze dressings alone. There was no animal mortality during the study period. CONCLUSIONS: Bandages containing fibrinogen and thrombin significantly reduced the amount of blood loss and allowed mean arterial pressures to be maintained in animals with uncontrolled hemorrhage from femoral artery lacerations. A hemostatic bandage may be an important adjuvant for controlling severe extremity hemorrhage in the prehospital setting.

Animals↗
PubMed1995

Total vascular exclusion for major hepatectomy in patients with abnormal liver parenchyma.

BACKGROUND: Total vascular exclusion (TVE) of the liver has been used to increase the safety of hepatectomy and the feasibility of difficult resections. Until recently, however, concern about the detrimental effect of warm ischemia has limited the use of this technique to patients with normal liver parenchyma. OBJECTIVE: To compare surgical outcomes of 12 patients with abnormal livers (group 1) with outcomes of 48 patients with normal parenchyma (group 2), based on the hypothesis that uncontrolled bleeding may be more detrimental than planned hepatic ischemia. DESIGN AND SETTING: Retrospective analysis of 60 consecutive patients undergoing liver resection under TVE in a university medical center. PATIENTS: All 10 patients with cirrhosis had albumin levels of 30 g/L or higher and normal prothrombin times preoperatively; none had ascites. Two patients with cholestasis (one with cholangiocarcinoma and one with hepatocellular carcinoma) are included in group 1. INTERVENTION: All 12 group 1 patients and 44 of 48 group 2 patients underwent total or extended lobectomy, with TVE induced by clamping the hilum and the vena cava above and below the liver during parenchyma division. MAIN OUTCOME MEASURES: Hospital survival and selected surgical and laboratory parameters. RESULTS: Operative times, ischemic times, and blood loss (1975 +/- 1601 vs 1255 +/- 1291 mL) (P = .10) were comparable in both groups. Sixty-day operative mortality was zero in both groups. There was an increased rate of complications in group 1 (44% vs 17% [P = 0.06]). Transient abnormal liver function was observed in both groups. However, significant delay in restoration of normal function was observed in group 1 with respect to bilirubin levels and prothrombin time. CONCLUSIONS: Patients with cirrhosis can undergo successful resection using TVE. This conclusion must be limited to cirrhotic patients with good liver function. The trend toward increased blood loss may reflect greater difficulties in establishing hemostasis after reperfusion in group 1. While this group appears to have a higher risk for hepatic insufficiency, successful outcomes were achieved in all cases. Prospective study will be required to define the parameters for use of TVE in cirrhosis.

Aged↗
PubMed1995

Extraluminal, transluminal, and observational treatment for vertebral artery injuries.

Injury to the vertebral artery following penetrating trauma is rare and treatment is usually surgical ligation. Recent liberal use of angiography in the evaluation of penetrating neck trauma has identified increasing numbers of patients with this challenging injury. This report describes our recent experience in treating patients with vertebral artery injuries. The purposes of this study were (1) to review the outcome of our patients with vertebral artery injuries, and (2) to develop an approach for managing these patients. Sixteen patients were treated over a 9-year period. Three patients underwent emergent operative exploration for bleeding, three underwent transcatheter embolization alone, and ten were managed conservatively by close clinical observation. No deaths occurred. Ligation was performed for injuries discovered during neck exploration, however, bleeding was sometimes persistent despite proximal control. In our center, where radiological support is readily available, temporary control of bleeding by packing with hemostatic agents allowed subsequent transcatheter embolization of the injured artery. Pseudoaneurysms, arteriovenous fistulae, and extravasations discovered angiographically were usually managed by transcatheter embolization. Patients with vertebral artery narrowings or occlusions were managed by close clinical observation.

Adolescent↗
PubMed1994

Morbidity and mortality following major penetrating liver injuries.

OBJECTIVE: To establish the mortality and morbidity associated with major penetrating liver injuries and to describe the nature and treatment of complications related to these injuries. We postulated that there had been a trend toward less radical initial surgery, as well as an increased utilization of modern imaging techniques in both diagnosing and treating postoperative complications following penetrating liver trauma. DESIGN: A retrospective survey of medical records and radiology files. SETTING: A university trauma center in an urban setting. PATIENTS: Of the 188 patients admitted to our trauma center with penetrating liver trauma between April 1988 and December 1991, 36 had major liver trauma (grades 3 through 5) and are described in this report. MAIN OUTCOME MEASURES: The mortality rate, type of operative treatment, and the nature and treatment of complications for each grade of major liver injury. RESULTS: The mortality rate from major liver injuries was 17%. Surgical techniques employed primarily consisted of the use of hemostatic agents and cautery, simple suturing, direct vessel ligation, and packing. Fifty-two percent of the survivors had major complications related to the liver injury itself, but only two required operative therapy. The remaining patients were successfully treated with interventional radiologic techniques. CONCLUSIONS: The morbidity and mortality following major penetrating liver injuries remain significant. The majority of hepatobiliary complications can be successfully managed without further surgery but require the combined efforts of the surgeon and interventional radiologist.

Abdomen↗
PubMed1993

Failure of glow-discharge polymerization onto woven Dacron to improve performance of hemodialysis grafts.

PURPOSE: The ideal conduit for hemodialysis vascular access remains elusive. Autogenous fistulas and prosthetic grafts, most commonly expanded polytetrafluoroethylene (e-PTFE), have adequate long-term patency rates (60% to 80% at 1 year); however, considerable delay in their use (2 to 6 weeks) is required. The Plasma-TFE graft is a recently introduced thin-walled woven Dacron graft to which an ultrathin layer of tetrafluoroethylene is bonded through a process of glow-discharge polymerization. This process purportedly results in a graft with an internal surface of low thrombogenicity. Low thrombogenicity, combined with the healing characteristics of a woven graft, have led to claims of equivalent patency rates even when used for dialysis immediately (within 1 week) after implantation. METHODS: This concept led us to use this new graft material in 19 fistulas (12 forearm and 7 arm) during a 1-year period. RESULTS: Although early use was possible, the primary and secondary patency rate at 12 months was only 47.4%. Ten grafts required replacement, five within the first month and two in the second month. Attempts at fistula revision failed because of unsuccessful graft thrombectomy or exuberant intimal hyperplasia. Failure was not associated with early use. During the same time period, 28 PTFE grafts were implanted, with only four failures (primary patency 78.6%; secondary patency 85.7%; p = 0.028). The secondary patency rate was the same for Plasma-TFE grafts (47%) but improved to 85.7% for e-PTFE grafts (p = 0.005). Both groups were comparable with respect to age, diabetes, previous dialysis access procedures, and other comorbid conditions. CONCLUSIONS: These early results have been sufficiently disappointing that we have abandoned use of this graft approved for hemodialysis by the Food and Drug Administration and cannot recommend it for other clinical indications. Nevertheless, the concept of plasma-discharge polymerization is theoretically attractive and might be useful in future graft configurations.

Adult↗
PubMed1991

Calciphylaxis in secondary hyperparathyroidism. Diagnosis and parathyroidectomy.

Calciphylaxis is a rare, severe complication of secondary hyperparathyroidism. Patients present with painful, violaceous, mottled skin lesions of the upper and lower extremities, which become necrotic and produce nonhealing ulcers. Gangrene of fingers and toes frequently requires amputation, produces nonhealing wounds, and can lead to sepsis and death. We reviewed the clinical course of five patients with calciphylaxis treated in our institution. The three men and two women (aged 47 to 72 years) had secondary hyperparathyroidism from chronic renal failure. All patients had severe pruritus, painful ulcers, and severe hyperphosphatemia with elevated serum calcium-phosphate product (greater than 12 mmol2/L2), but the serum parathyroid hormone levels were only moderately elevated. Most patients had medical calcification of medium and small blood vessels, and some had soft-tissue calcification visible on roentgenography. Treatment consisted of local wound care, antibiotics, phosphate-binding agents, and parathyroidectomy. Two patients died of uncontrollable sepsis. The three survivors had dramatic improvement of pain and ulcers after parathyroidectomy. Calciphylaxis is a limb- and life-threatening complication of secondary hyperparathyroidism. Diagnosis can be made by recognizing the characteristic painful skin lesions, ulcers, and gangrene of the digits, and patients should be treated with subtotal parathyroidectomy.

Aged↗
PubMed1991

Cervicothoracic vascular injuries. Presentation, management, and outcome.

One hundred consecutive patients with cervicothoracic vascular trauma were analyzed. The injury severity score, mechanism of injury, age, initial findings, management, and results were tabulated. There were 48 arterial and 61 venous injuries in the stable Group A patients, 11 arterial and 12 venous injuries in the unstable Group B patients, and three arterial and five venous injuries in the morbid Group C patients. Treatment included primary repair, resection with end-to-end anastomosis, or ligation. Twenty-three patients developed postoperative complications, the most common being respiratory in nature. The overall mortality rate was six per cent. Five patients died during or immediately after operation of exsanguination, and one died of ischemic brain death on the seventh postinjury day. The usefulness of preoperative angiograms, especially in the detection of arteriovenous fistulas, is important in planning the surgical approach. The overall outcome was favorable.

Adolescent↗
PubMed1990

Nonoperative management of blunt liver injuries in adults: the need for continued surveillance.

Computed tomography (CT) scanning after blunt abdominal trauma has allowed nonoperative management of selected patients with liver injuries. This report describes 52 adult patients with liver injuries who were treated without immediate surgery. Thirty-four of these hepatic injuries were relatively minor (Grade I-II), and 18 were considered major (Grade III-V). Free intraperitoneal blood in small to large amounts was evident on CT in 37 patients. There were no deaths in this series, no major complications, no known missed intra-abdominal injuries, and no delayed hemorrhage. While most liver injuries appear to heal rapidly by serial CT scans, a small percentage of these patients have residual liver defects persisting for several months and may be at risk for future complications.

Adolescent↗
PubMed1989

Popliteal artery entrapment: an evolving syndrome.

Popliteal artery entrapment can result in claudication and limb-threatening ischemia in the young adult. The purpose of this study was to evaluate prospectively those patients with popliteal artery entrapment. To define the syndrome, the methods used in diagnosis and the type of anatomic anomaly were established for each patient. From 1977 to 1988, 12 patients were found to have popliteal artery entrapment. The average age was 27 years, with all but three patients under age 40 years. All patients complained of calf claudication, and one had acute ischemia. The ankle pulses decreased with maneuvers in 10 patients; four patients had a resting ankle/brachial index less than one. All had diminished ankle/brachial indexes when a treadmill test was performed at 4.2 mph, 10% grade, for 10 minutes. All patients had biplanar arteriography with passive dorsiflexion and active plantar flexion. All results showed abnormal extrinsic compression or occlusion of the popliteal artery. Twenty limbs were affected; eight of 12 patients (67%) had bilateral entrapment. Type IV (37%) lesions were the most common, with type II (32%) and type III (26%) following closely. One (5%) type I lesion and no type V lesions were found. This is the largest single series of patients with popliteal entrapment in the United States. A treadmill test followed by biplanar arteriography established the diagnosis in all patients. Bilateral involvement was twice that reported in previous studies. Popliteal artery entrapment should be considered in the young adult with claudication and may be seen with greater frequency in an increasingly active population.

Adult↗
PubMed1989

Reduction in HLA-DR, HLA-DQ and HLA-DP expression by Leu-M3+ cells from the peripheral blood of patients with thermal injury.

Monocytes that bear HLA Class II antigens, such as HLA-DR, HLA-DQ, or HLA-DP, are obligatory for many cell-mediated immunological processes. Patients with thermal injury suffer from hypoimmunity and are at risk for developing life-threatening septic episodes. To determine whether an alteration in expression of HLA Class II antigens is involved in the defect, monocytes from the peripheral blood of burn patients and controls were double-stained with anti-Leu-M3 and either anti-HLA-DR, HLA-DQ, or HLA-DP monoclonal antibodies. As analysed by flow cytometry the percentage of Leu-M3+ monocytes from the peripheral blood from patients and controls was the same. The percentage of Leu-M3+ monocytes bearing the HLA Class II antigens and the density of antigen on the monocytes, however, was significantly reduced post-burn compared with controls. In nearly all cases these changes were detected as early as 24 h post-burn before any drug therapy was implemented. In-vivo re-expression of normal levels of HLA Class II coincided with patient recovery. In-vitro exposure of post-burn Leu-M3+ cells to IFN-gamma for 72 h restored HLA Class II expression to control levels. It is possible that the reductions in HLA Class II expression may be involved in the general immunosuppression that follows thermal injury.

Adult↗
PubMed1988

A step-wise logistic regression analysis of hepatocellular carcinoma. An aspiration biopsy study.

Fine needle aspiration biopsy (FNAB) has become a popular method to diagnose mass lesions of the liver. Although several reports have listed FNAB criteria to be used to diagnose both primary and metastatic tumors of the liver, none have separated key cytologic criteria from secondary criteria. We reviewed the FNAB smears from 35 patients with proven hepatocellular carcinoma and 74 patients with proven metastatic tumors in the liver. All specimens were coded as to the presence or absence of the following variables: polygonal cells with centrally placed nuclei; well-defined, granular cytoplasm; large nucleoli; small cytoplasmic vacuoles; large cytoplasmic vacuoles; bile; polymorphonuclear leukocytes; malignant cells separated by sinusoidal vessels; endothelial cells surrounding tumor cell clusters; multinucleated tumor giant cells; basophilic intracytoplasmic inclusions; eosinophilic intracytoplasmic inclusions; and intranuclear cytoplasmic inclusions. A step-wise logistic regression analysis was performed on the data to determine the variables predictive of hepatocellular carcinoma. The statistical analysis selected polygonal cells with centrally placed nuclei, malignant cells separated by sinusoidal capillaries, and bile as the key cytologic criteria for hepatocellular carcinoma. Endothelial cells surrounding tumor cell clusters and intranuclear cytoplasmic inclusions were selected as secondary criteria by this analysis.

Biopsy, Needle↗