The Impact of SARS-COV-2 on two Colorectal Cancer screening centres.

BowelScreen paused activity in March 2020 to prioritise the response to the COVID-19 pandemic. The aim of this study was to examine the impact of this delay. Cases affected by the pause and subsequently completed were compared to the same period in 2019. Endoscopy and histology data were obtained from the BowelScreen database and patient records. One-hundred and seven colonoscopies were performed during the study period. This compared with 224 colonoscopies during the same period in 2019. Median lead time to colonoscopy in 2020 was 74 days compared to 34 days in 2019. Adenoma detection rate was 59% for both periods. Advanced adenoma and cancer detection rates were similar in both periods. While there was a marked reduction in activity and significant delays for BowelScreen patients during the first wave of the COVID-19 pandemic, this does not appear to have impacted on clinical outcomes for patients who attended for screening colonoscopy.

Silicon nitride windows for electron microscopy of whole cells.

Silicon microchips with thin, electron transparent silicon nitride windows provide a sample support that accommodates both light-, and electron microscopy of whole eukaryotic cells in vacuum or liquid, with minimum sample preparation steps. The windows are robust enough that cellular samples can be cultured directly onto them, with no addition of a supporting film, and there is no need to embed or section the sample, as is typically required in electron microscopy. By combining two microchips, a microfluidic chamber can be constructed for the imaging of samples in liquid in the electron microscope. We provide microchip design specifications, a fabrication outline, instructions on how to prepare the microchips for biological samples, and examples of images obtained using different light and electron microscopy modalities. The use of these microchips is particularly advantageous for correlative light and electron microscopy.

The historical development of thermometry and thermal imaging in medicine.

Human body temperature has been an important part of medicine since very early times. However, until the thermometer was developed in the 16th century measurement was not possible. Some 200 years later, Wunderlich laid the foundation for clinical thermometry, and temperature charts became commonplace throughout the world. More recently thermal imaging has broadened the understanding of body surface temperature in health and disease. Standards for computer-assisted infrared imaging are well developed, and present-day fast high-resolution imaging is less expensive and more reliable than it was 40 years ago.

Chemoembolization for hepatocellular carcinoma.

Fifty-one patients with unresectable hepatocellular carcinoma (HCC) were treated with Gelfoam (absorbable gelatin sterile powder; The Upjohn Co, Kalamazoo, MI) chemoembolization. A mixture of Gelfoam powder, contrast media, and three drugs (doxorubicin, mitomycin, and cisplatin) was injected under fluoroscopic guidance via a percutaneous catheter into the hepatic artery until stagnation of blood flow was achieved. Of the 51 patients, 50 are assessable for response, and all are assessable for toxicity and complications. The median percent of liver replacement was 50% (range, 15% to 95%). By conventional response criteria, there were 12 partial responses (PRs) (24%), 13 minor responses (MRs) (26%), 12 stabilization of disease (SD) (24%), and 13 (26%) progressive disease (PD). Tumor liquefaction was noted on computed tomographic (CT) scan in 35 of 50 patients (70%). Of the 34 patients with elevated alpha-fetoprotein (AFP), 23 (68%) had a greater than 50% reduction following treatment. Responding patients were re-treated at the time of tumor progression if they still met the entry criteria. The median survival of assessable patients from the time of treatment was 207 days and from the diagnosis of the primary was 302 days. Fourteen patients remain alive at 3 months to 3 years following treatment. The vast majority of patients had transient pain, fever, nausea, and elevation in liver enzymes. Ascites developed in 14 patients. There were two treatment-related deaths: one from tumor hemorrhage and one from liver failure. Chemoembolization appears to have significant activity in patients with hepatocellular carcinoma and is relatively well tolerated.

The management of T tube leaks in orthotopic liver transplant recipients with endoscopically placed nasobiliary catheters.

Biliary tract problems remain an important cause of complication following orthotopic hepatic transplantation. We describe 12 liver transplantation patients who developed bile peritonitis secondary to a biliary leak after T tube removal. Each of these patients underwent an urgent ERCP that exhibited leakage outside the T tube tract and nondilated intrahepatic ducts. At the time of the ERCP, a nasobiliary catheter was inserted to divert the bile flow. All of these patients resolved their symptoms and closed their leak. We advocate endoscopic placement of a nasobiliary catheter as first-line therapy for significant T tube tract leaks after liver transplantation.

Nonoperative management of biliary leaks after orthotopic liver transplantation.

Specific therapy should be instituted expeditiously once the diagnosis of a biliary leak has been made in patients who have undergone orthotopic liver transplantation. Controversy exists over whether to use nonoperative or operative management. The results of 325 consecutive orthotopic liver transplants in 297 adult and pediatric recipients were reviewed. The biliary tract was reconstructed using a choledochocholedochostomy anastomosis (254/325 or 78%) or a Roux-en-Y choledochojejunostomy anastomosis (71/325 or 22%). The incidence of biliary leaks was 23% (74/325). Overall, only 3% (10/325) of the orthotopic liver transplant recipients required operative repair of a biliary leak. Biliary leaks occurring in patients with Roux-en-Y choledochojejunostomy anastomoses (9/71 or 13%) commonly required operative repair (6/9 or 67%), whereas leaks that occurred in patients with choledochocholedochostomy anastomoses (65/254 or 26%) seldom required operative repair (4/65 or 6%). All choledochojejunostomy leaks occurred at the anastomosis, whereas choledochocholedochostomy leaks occurred either at the anastomosis (17/254 or 7%) or the T-tube insertion site (45/254 or 18%). Our study confirms that in centers with proficient endoscopic and interventional radiologic support, resolution of biliary leaks in orthotopic liver transplant patients can be achieved with nonoperative management.

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.

Percutaneous transluminal angioplasty treatment of renal transplant artery stenosis.

Since June 1979, percutaneous transluminal angioplasty (PTA) has been the procedure of choice for renal transplant artery stenosis (RTAS) at the Hospital of the University of Pennsylvania. Of 241 renal allograft recipients, 17 (7%) when studied by arteriogram because of suspected RTAS proved to have significant stenosis (the mean reduction in luminal width for the group being 68%) and underwent PTA. RTAS was equally prevalent in cadaver and related kidney allografts and was no less common in HLA-identical related donor grafts, arguing against the importance of immune factors in etiology. RTAS was equally prevalent whether the anastomotic technique was end to end or end to side. However, when RTAS occurred after end to side anastomoses, it was usually postanastomotic. Fifteen of 17 of the attempts at dilation by PTA were successful by angiographic analysis. Thirteen of the 15 successfully dilated patients had long-term allograft survival and in all of these instances blood pressure (BP) was decreased after PTA. After a mean of 67 weeks, BP decreased from a systolic of 184 +/- 24 mm Hg pre-PTA to 135 +/- 15 mm Hg (P less than 0.001) and from a diastolic of 115 +/- 10 mm Hg pre-PTA to 87 +/- 11 mm Hg (P less than 0.001). The majority of patients continue to require antihypertensive drugs but in a less vigorous regimen than pre-PTA. Serum creatinine level fell following PTA from 1.9 +/- 0.6 to 1.7 +/- 0.5 mg/100 ml (P less than 0.01). Repeat angiographic study was done in nine patients, an average of 61 weeks after PTA, and no recurrent RTAS was identified. Three minor complications of PTA occurred but none led to long-term sequelae. Thus, we believe PTA of RTAS is relatively safe, carrying less mortality and morbidity than operative treatment, and is capable of improving BP control and renal allograft function.

Measurement of inflammation in man and animals by radiometry.

1. A radiometer is described, which is sensitive to infrared radiation in the range 0-25 mum, and which, after calibration with a black body standard can be used as a non-contact, fast reading thermometer.2. An example of acute joint inflammation in a patient with rheumatoid arthritis is described. The temperatures over the joint measured by radiometry, followed inflammatory changes in the joint effusion.3. Using rats, the method of measuring inflammation by radiometry was compared with measurements of increase in joint size. Changes measured by radiometry preceded changes shown by increase in joint size.4. The radiometer method was able to demonstrate the effect of an anti-inflammatory drug, given orally, against carrageenin inflammation.5. The procedure was found to be an accurate means of measuring inflammation and the anti-inflammatory effects of drugs. It was faster and less tedious than the other methods for the quantitative measurement of inflammation in man and animals.

Massive hemoptysis secondary to pulmonary arteriovenous fistula. Treatment by a catheterization procedure.

Massive pulmonary hemorrhage secondary to an acquired arteriovenous fistula is a rare event associated with high mortality. Cotton wads mounted on steel coils were inserted by percutaneous catheter and successfully occluded a pulmonary arteriovenous fistula in a patient who had massive hemoptysis and contraindications to thoracotomy.

Comparison of the effect of vasopressin infusions on the mesenteric arteries of different species.

Superior mesenteric arteriography was performed following infusions of vasopressin, epinephrine and saline into the superior mesenteric arteries of dogs, pigs, rabbits and monkeys and compared with the well-known effects in human beings. Species-specific effects were noted and compared with the known differences in various vascular beds in human beings. In non-primate animals, vasopressin appeared to act at a more distal site than in primates, but with a similar decrease in superior mesenteric arterial flow. The results in primates were similar to those in human beings.

Peripheral hepatic arterial embolization with crosslinked collagen fibers.

Hepatic artery embolization with a nonimmunogenic, crosslinked microfibrillar collagen preparation (Angiostat, Collagen for Embolization, Target Therapeutics, Los Angeles, CA) was studied in mongrel dogs. Flow-directed technique was used to achieve complete distal arterial occlusion. Serial liver function evaluation demonstrated marked alterations at 48 to 72 hours, partial correction at one week, and resolution of abnormalities by one month. Restoration of large vessel blood flow was angiographically demonstrable at one week. Follow-up arteriograms showed no persistent arterial occlusion. Collagen was demonstrated in vessels of 20 to 250 micron. Recanalization was achieved by migration of endothelial cells around the collagen, development of a new vascular channel within an endothelial cell cleft, and subsequent complete removal of the collagen over a three- to four-month period. Three months after embolization with a single dose, normal hepatic vascular and tissue anatomy and hepatic function were restored completely. Repeated embolization at two weekly intervals was well tolerated.

Five years experience with continuous extracorporeal renal support in paediatric intensive care.

Continuous arterio-venous haemofiltration (CAVH) and continuous veno-venous haemofiltration (CVVH) were used as renal support in 52 critically ill infants and children with acute renal failure. The majority of the patients were on mechanical ventilation (90%) and needed vasopressor support (85%). Uraemia was satisfactorily controlled with both treatment modes. Post-treatment serum urea levels were not different between survivors (94 +/- 8.8 mg/dl) and non-survivors (99.5 +/- 8.8 mg/dl). There were significant differences between survivors and non-survivors in the mean arterial pressure (64.7 +/- 3.8 vs 48.0 +/- 2.2 mmHg, p less than 0.001), the number of organ system failures (2.9 +/- 0.16 vs 3.8 +/- 0.21, p less than 0.025), and the severity of illness assessed by the acute physiologic score for children (APSC 19.4 +/- 1.9 vs 26.3 +/- 1.9, p less than 0.01). The overall mortality was 48%. The mortality in the CVVH group (65%) was higher than in the CAVH group (40%). Death was significantly related to sepsis (p less than 0.005) and multiple system organ failure (p less than 0.005). A major complication during CAVH was one femoral artery thrombosis after 12 days of treatment. Technical problems were only observed during CVVH. CAVH and CVVH are safe and effective methods of continuous renal support for critically ill paediatric patients with multiple system organ failure. CAVH is simpler, needs no specially trained staff and seems to the ideal renal replacement system for critically ill infants.

Preoperative balloon-tipped catheter placement for proximal control in visceral artery aneurysm surgery.

A 13 cm false aneurysm of the common hepatic artery developed after repeated episodes of pancreatitis in a 47-year-old man with diabetes who was undergoing chronic hemodialysis. A balloon-tipped catheter was positioned in the common hepatic artery before operation. This maneuver allowed proximal control of the aneurysm and suture closure of the hepatic artery defect with minimal dissection and blood loss in this high-risk patient.

Value of routine vascular laboratory studies to identify vein graft stenosis.

Thirty-three stenotic lesions were found in 30 vein grafts (17 femoral-popliteal, 13 femoral-tibial) 3 months to 8 years postoperatively--77% appeared within 1 year of surgery. Seventeen (57%) of the patients presented with normal distal pulses, and a similar number were asymptomatic. Only eight (26%) presented with unequivocal clinical evidence of graft stenosis based on decreased pulses and return of ischemic symptoms. Forty percent were completely asymptomatic with normal distal pulses. The mean postoperative ankle systolic pressure index (ASPI) was 0.83 +%- 0.03 (SEM); it fell to 0.57 +/- 0.04 (SEM) when stenosis developed. The peripheral vascular laboratory measurements were the key factor influencing the decision for repeat arteriography in many of these patients and reinforced the need for a repeat arteriogram when the clinical diagnosis was unclear. Early diagnosis of vein graft lesions prior to graft occlusions allowed 24 of 30 of these stenotic grafts to be treated primarily by percutaneous transluminal angioplasty (PTA); 80% remained patent 24 months after PTA. Since most vein graft stenoses can be treated by such a simple, nonoperative technique (PTA), every effort should be made to diagnose and treat lesions prior to graft occlusion. Our experience indicates that frequent vascular laboratory measurements of ASPI are more sensitive then clinical examinations in detecting early vein graft stenosis.

Treatment of acute peripheral arterial and graft thromboses with low-dose streptokinase.

Seventeen patients with acute peripheral arterial or graft occlusion were treated with local low-dose intra-arterial streptokinase. The series includes eight patients with native vessel occlusion, six patients with vein graft occlusion, two patients with prosthetic graft occlusion, and one patient with renal allograft artery occlusion. The duration of occlusion prior to streptokinase therapy varied from 2 hours to 5 weeks. The treatment was successful in 14 of the 17 instances. In conjunction with the successful thrombolytic therapy, percutaneous transluminal angioplasty was performed subsequently in 10 of the patients and reconstructive surgery in three. One major and five minor hemorrhagic complications occurred and were considered to be secondary to the streptokinase therapy. In follow-up of up to 9 months, 11 of the 14 successfully treated patients continued to have a good result, without any indication of recurrent arterial occlusion. Two patients have died of causes unrelated to thrombolytic therapy and one patient required bypass grafting for recurrent thrombosis. None of the successfully treated patients lost a limb. Of the three patients in whom thrombolysis was unsuccessful, two required amputation. Local intra-arterial low-dose streptokinase appears to be a promising alternative to immediate operative treatment in carefully selected cases of arterial occlusion. Definitive treatment of the underlying cause of the thrombus usually is required and changes of success may be enhanced by the thrombolytic therapy.

Balloon-catheter dilation as an adjunct to arterial surgery.

Balloon-catheter dilation of arterial stenoses and/or occlusions has been found to be helpful when used both as an adjunct to arterial surgery and as definitive treatment. Used preoperatively, it enables the extent of surgery to be limited and may improve the patient's general condition and ability to undergo surgery; such is seen when renal or mesenteric vessels are dilated preoperatively. During surgery, it can be used to augment the surgery, particularly in an area that is difficult to expose or out of the operative field. Postoperatively, it is often useful in maintaining patency of a graft or its inflow and outflow tract. Judicious use of this modality can enhance arterial surgery and improve results.

Continuous renal replacement therapy in critically ill patients.

We describe our experience with continuous renal replacement therapy (CRRT) in critically ill neonates. From June 1995 to June 1997 36 critically ill oliguric or anuric infants and children underwent continuous arterio-venous (N = 17) or veno-venous (N = 15) renal support. In addition, four neonates were treated with continuous ultrafiltration (CUF) during extracorporeal membrane oxygenation (ECMO) because of severe diuretic-resistant hypervolemia. Their mean age was 9.8 +/- 1.5 days, their mean body weight 3.0 +/- 0.1 kg. The membrane surface area of the hemofilters ranged from 0.015 m2 to 0.2 m2 and the priming volume from 3.7 to 15 ml. For pump-driven hemofiltration a roller pump with pressure alarms, an air trap, an air bubble detector, and small blood lines was used. Fluid balance was controlled by a microprocessor controlled unit. The ultrafiltrate substitution fluid was based on bicarbonate in the majority of the patients and was partially or totally replaced according to the clinical situation. The mean duration of renal support was 97 +/- 20 hours, ranging from 14 to 720 hours. During arterio-venous and veno-venous hemofiltration the mean blood flow rates were 7.0 +/- 1.2 ml/min and 23.1 +/- 2.4 ml/min (P < 0.01), respectively, and the mean ultrafiltration rates 3.3 +/- 0.4 and 9.5 +/- 1.9 ml/min/m2 (P < 0.01), respectively. During continuous hemodiafiltration urea clearances increased by 300%. Overall survival rate was 66%. CRRT related complications included local bleeding at the catheter entrance site, partial thrombosis of the inferior or superior caval veins and transient ischemia due to femoral artery catheters. Continuous hemofiltration either driven in the arterio-venous or veno-venous mode is a very effective method of renal support for critically ill neonates to control fluid balance and metabolic derangement. Urea clearance can be improved by adding some dialysate fluid in a countercurrent direction to blood flow.

Removal of a distal common bile duct stone through percutaneous transhepatic catheterization.

A residual distal common bile duct stone was successfully advanced into the duodenum after percutaneous transhepatic catheterization of the biliary tract. Nonsurgical retrieval of retained biliary duct stones through surgically created T-tube tracts has been shown to be a practical procedure with high reported success rates. Reoperation has been necessary in cases where no drainage tube was introduced at surgery or when stones have formed after the fistula closed. Transhepatic catheterization techniques may provide a way to manipulate residual biliary tract stones when no other access is available.

Balloon dilation of iliac stenosis with distal arterial surgery.

Seven patients with concomitant atherosclerotic iliac stenosis and femoral artery occlusive disease were treated with polyvinyl balloon catheter dilation of the iliac artery and subsequent distal operative arterial reconstruction. The iliac lesions were short, localized, common and external iliac stenoses and the femoral lesions were superficial femoral artery occlusions in six patients and a common femoral occlusion in another. All seven iliac stenoses were successfully dilated. Subsequent operative femoral artery reconstruction was successful in these patients, with restoration of popliteal or pedal pulses and relief of ischemic symptoms over a follow-up period of two to 14 months. One patient's femoral popliteal bypass graft thrombosed four months postoperatively.