Surgical management of infected abdominal aortic grafts: review of a 25-year experience

Eighty-four patients with infected abdominal aortic grafts managed from 1961 through February 1985 were reviewed. Thirty-three patients had associated aortoenteric fistula formation. Twenty-eight infections (33%) and 13 aortoenteric fistulas (39%) originated at The Cleveland Clinic, yielding an incidence of aortic graft infection of 0.77% (28 of 3652 grafts) and aortoenteric fistula formation of 0.36% (13 of 3652 grafts) at this center. Staphylococcus organisms alone or in combination with other organisms were isolated from 34% of the series. Management consisted of graft removal and extra-anatomic bypass in 54 patients (64%), graft removal alone in 14 (17%) patients, partial graft removal and extra-anatomic bypass in seven (8%) patients, and miscellaneous operations in nine (11%) patients. Twenty-three patients (27%) required major amputations, nine of which were bilateral. Life-table analysis yielded 30-day and 1-year survival rates of 72% and 42%, respectively. Thirty-day survival of the aortoenteric fistula subset (49%) was less than that (86%) of the nonaortoenteric fistula subset (p = 0.003). One-year survival of patients treated since 1980 (54%) was superior to that of patients treated before 1980 (31%, p = 0.035). No difference in operative or 1-year survival was demonstrated between the group treated with extra-anatomic bypass and subsequent graft removal and another in which both procedures were performed simultaneously, although the staged group experienced substantially fewer (p = 0.04) amputations (7%) than the combined group (41%).     

Peripheral artery and bypass graft thrombolysis with recombinant human tissue-type plasminogen activator

Recombinant tissue-type plasminogen activator (t-PA) is a DNA-synthesized thrombolytic agent recently approved for clinical trials. We present the results of t-PA infusions in 18 patients with thrombosed peripheral arteries (12 patients) and peripheral bypass grafts (six patients). The duration of occlusion ranged from 1 to 21 days (mean, 6.8 days). Infusions of t-PA were done by way of an intra-arterial approach at a dose of 0.1 mg/kg/hr. All patients demonstrated thrombus lysis angiographically. Fifteen of 18 (83%) had clinical as well as angiographic improvement. Secondary procedures to maintain patency of the arterial segment were required in seven patients. No complications occurred that were related to the t-PA infusion. No significant prolongation of the prothrombin, thrombin, or activated partial thromboplastin times occurred. At the end of t-PA infusion, the mean circulating fibrinogen level was 59% of the starting value. The therapeutic use of t-PA is still in its preliminary stages and the efficacy and safety of this promising agent need to be further established. From our early experience with t-PA, it appears to be safe as well as effective.     

Diagnosis and treatment of status epilepticus on a neurological intensive care unit

Status epilepticus refractory to first-line therapy is associated with a high morbidity and mortality. Correct diagnosis and adequate treatment of this condition require electrographic monitoring and anaesthetic facilities available in specialist intensive care units (ICUs). We carried out an audit of 26 patients admitted to a neurological ICU with a diagnosis of status epilepticus, to identify deficiencies in diagnosis and management prior to transfer to the ICU, and examine the effectiveness of ICU management. Or transfer, only 14 (54%) were in status epilepticus; six were in drug-induced coma or were encephalopathic, and six had pseudostatus epilepticus, of whom four had been intubated. The commonest treatments prior to transfer were benzodiazepines, chlormethiazole and phenytoin; the loading dose of phenytoin was adequate in at least 7/16 cases. All those in status epilepticus on transfer had their seizures successfully controlled, but ten required general anaesthesia with thiopentone, propofol, ketamine or midazolam. Two died--one had a severe encephalitis and the other had had a cardiac arrest prior to treatment. This study highlights deficiencies in the initial diagnosis and management of status epilepticus, the role of specialist neurological intensive care, and the importance of early referral.      

兔视网膜色素上皮细胞移植及长期形态学的研究

视网膜色素上皮（ＲＰＥ）功能失调或发生病理改变，可导致许多视网膜疾病，包括年龄相关性黄斑变性，青年性遗传性黄斑变性及视网膜色素变性等，严重危害人类视力。能否通过移植正常、健康的ＲＰＥ细胞治疗这类视网膜疾病，是当前眼科界关注的重要研究课题。我们采用了改良式玻璃体密闭式移植术，术中增加了玻璃体切割，应用带有色素标记的兔ＲＰＥ细胞移植于无色素性兔的视网膜下间隙。结果显示，移植长达１年后的ＲＰＥ细胞不但存活，结构形态正常，并且与邻近的ＲＰＥ细胞（包括移植的与自体的）建立了闭锁小带。移植的ＲＰＥ细胞与受体的感光细胞紧密结合，受体眼的神经外节盘正常脱落，被移植的ＲＰＥ细胞吞噬，且未发生排异反应。上述结果显示，本实验兔ＲＰＥ细胞移植的成功，为临床治疗某些视网膜疾病开辟了新的治疗途径，提供了可靠的实验室根据和应用前景。     

Electric compound action potentials (ECAPs) and impedances in an open and closed operative site during cochlear implantation

Introduction: In patients undergoing cochlear implantation, intraoperative measures of impedance and electrically evoked compound action potentials (ECAPs) are used to confirm device integrity and electrode array position. However, these electrophysiological parameters have been shown to decrease over time, with a small decrement observable as early as 24?h post implantation and becoming more apparent after 6 months. Whether the intraoperatively measured impedances and ECAPs recorded immediately after electrode insertion versus later in the operation or in an open versus closed operative site vary has not been documented. Such variation in measurement procedure may affect the ultimate operative outcome.

Patients and methods: Between February and October 2016, 38 patients received a cochlear implant (Cochlear^®), with half receiving a CI 522 device and the other half receiving a CI 512 device. These patients were distributed into three groups. In the first (group A; n?=?21), the impedance and threshold neural response telemetry (tNRT) measures were taken before (M1) and after cutaneous suture (M2), whereas in the second group (group B; n?=?11) they were taken twice in the open operative site, once at the time of electrode insertion (M1) and then again 10?min later (M2). The last group (group C; n?=?6) was measured only once after a 10?min waiting time before closing the operative site.

Results: tNRTs of both group A and B were significantly higher at M1 than measured at M2. The magnitude of change in tNRT did vary significantly by group (P?=?.027) with group A having a bigger decrease than group B. For impedances there was evidence for a significant difference in M2 between the three groups (P?=?.012), with group C having significantly higher values compared to group A and B.

Conclusion: Intraoperative tNRT measures change significantly over time, including within the first 10?min of implantation. One underlying etiology of this phenomenon for tNRTs seems to be the condition of the surgical site whereas changes of impedances can be best explained by the ‘electrochemical cleaning’ theory associated with the first stimulation of the electrode. However, for both impedances and tNRTs there also is an important impact of time as well as of acute perioperative changes in electrical conductivity.     

Quantitative determination of bone marrow transplant engraftment using fluorescent polymerase chain reaction primers for human identity markers

We have developed a quantitative, nonisotopic method using variable number tandem repeat (VNTR) and short tandem repeat (STR) markers for monitoring donor cell engraftment in marrow transplant recipients. Posttransplant DNA from the recipient is amplified with fluorescent polymerase chain reaction (PCR) primers for polymorphic markers that distinguish donor alleles from recipient alleles. The fluorescent PCR products are then separated on agarose or acrylamide gels on the Applied Biosystems 373A Sequencer (Foster City, CA). Using GeneScan 672 software (Applied Biosystems) to analyze the separated alleles, we can correlate allele peak areas to the percentage of donor or recipient DNA. We quantitate engraftment in a mixed chimeric sample by mixing pretransplant recipient and donor DNAs in a range of percentages and amplifying the mixtures to produce a standard curve. By amplifying and analyzing the posttransplant sample DNA(s), we can determine the extent of engraftment by interpolating the percent peak area of the informative allele(s) from this standard curve. This approach provides a precision of measurement ranging, depending on the marker, from 3.5% to 8.0% (percent coefficient of variation) and an accuracy of engraftment determination ranging from 97% to 99%, with a sensitivity of detection of 1% donor or recipient DNA. We retrospectively analyzed a panel of 32 patients and found seven to be informative for some degree of mixed chimerism, indicative of either residual normal host cells or leukemic relapse. An analysis of different cell lineages obtained posttransplant showed different degrees of engraftment in myeloid and T-cell populations. In summary, this method can provide an accurate, quantitative assessment of mixed chimerism in patients posttransplant. Such information may be useful in the future in guiding early implementation of additional treatment designed to circumvent graft failure or suppress relapse.     

Evaluation of the relationship between circulating nucleated red blood cells count and inborn infection in neonates

OBJECTIVES: to determine the relationship between the initial nucleated red blood cells (nRBC) count during the first 12 hours after birth and inborn infection in neonates. MATERIALS AND METHODS: The retrospective study comprised of 306 neonates born in the Department of Perinatology of the I Chair of Gynaecology and Obstetrics in ?ód?, Poland, in the years 2002-2007, among whom the nucleated red blood cells count were calculated within the first 12 hours after birth. Two categories of nRBC count: the normal and the elevated value, were statistically elaborated by a Mann-Whitney test and a chi-square test with two clinical outcome categories: the presence and the absence of inborn infection in the analyzed neonates. Statistical significance was indicated by p value lower than 0,05. RESULTS: Among 306 newborns, there were 127 mature neonates (41.5%) and 179 prematures (58.5%). The mean of the initial nRBC count in the analyzed newborn population was 40, 15. The mean of the nRBC count in the infected neonates was three times higher (52.56) than the mean of the nRBC count in newborns without inborn infection (16.76) - (p=0.00001). Inborn neonatal infection concerned a vast majority of cases with an elevated value of the nRBC count (86.4%), but in 13.6%, inborn infection was not observed. Among the cases with a normal nRBC count, the presence and the absence of inborn infection was diagnosed in about 50% of the analyzed babies (50.83% vs 49.17%). The elevated value of the nRBC count in infected neonates concerned mainly premature babies, rather than mature neonates, and similarly in neonates with a lower Apgar score than in babies born in good condition. CONCLUSIONS: 1. The positive association between elevated initial nucleated red blood cells count after birth and inborn infection in newborns has been revealed. 2. An elevated nucleated red blood cells count may be an auxiliary, early indicator for inborn infection in neonates. 3. Prematurity and perinatal asphyxia favour the elevation of a nucleated red blood cells count in cases with inborn infection.     

Imaging of uncommon esophageal malignancies

Malignant esophageal neoplasms other than squamous cell carcinoma and adenocarcinoma are uncommon and include endocrine tumors, lymphoid malignancies, melanoma, malignant stromal tumors, and secondary tumors (metastases). Imaging, though not diagnostic in many cases, helps in selecting the appropriate treatment strategy by determining the anatomic extent of the tumor and locoregional and distant spread. In this article, we provide a comprehensive review of the imaging features of these uncommon esophageal malignancies.