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Biomedical subjects

T G John

Publications and source records attributed to T G John.

36 records · Page 2Linked to original sources
PubMed1994

Carotid endarterectomy in Great Britain and Ireland: practice between 1984 and 1992.

Of 356 questionnaires on carotid endarterectomy sent to all vascular surgeons in Great Britain and Ireland likely to undertake this procedure, 326 (92 per cent) were returned. Of those who replied 131 (40 per cent) performed at least one carotid endarterectomy in 1992; 57 (44 per cent) of these carried out ten or fewer operations and 74 (56 per cent) more than ten. The 131 surgeons were collectively responsible for 2628 operations in 1992, twice as many as were undertaken in either 1984 or 1989, years for which similar survey data are available. This sharp rise in the number of operations was accounted for by increased activity on the part of experienced operators, rather than any rise in the number of 'occasional' carotid surgeons. In 1992, although the neurologist remained a major source of patient referral, general practitioners (and others) were also referring patients in large numbers direct to the vascular surgeon; this represents a change in practice compared with previous years. Many of the technical aspects surrounding carotid endarterectomy remained unchanged over the years surveyed (1984, 1989, 1992) but by 1992 duplex scanning, intra-arterial (but not intravenous) digital subtraction angiography and transcranial Doppler ultrasonography had become established as clinically useful techniques.

Anesthesia↗
PubMed1994

Laparoscopic ultrasonography in the evaluation of the biliary tree during laparoscopic cholecystectomy.

A prospective comparative study to evaluate operative cholangiography and laparoscopic ultrasonography in the detection of common bile duct (CBD) stones was undertaken in 54 patients undergoing laparoscopic cholecystectomy. Laparoscopic ultrasonography with a 7.5-MHz linear-array probe was performed before gallbladder mobilization. The incidence of choledocholithiasis at operation was 13 percent (seven patients). Cholangiograms were not obtained in six patients, one of whom had common duct stones identified by laparoscopic ultrasonography. Operative cholangiography detected five of the remaining six CBD stones with two false-positive examinations. Laparoscopic ultrasonography detected five of the seven stones with two false-positive examinations. The finding of a CBD diameter of 7 mm or greater and gallbladder stones of up to 3 mm in diameter by laparoscopic ultrasonography would have identified all patients with common duct stones and implies that none of these would have undergone false duct exploration. Laparoscopic ultrasonography is useful in the detection of choledocholithiasis.

Adult↗
PubMed1994

Preliminary experience with intracorporeal laparoscopic ultrasonography using a sector scanning probe. A prospective comparison with intraoperative cholangiography in the detection of choledocholithiasis.

Laparoscopic ultrasonography is a novel technique which may be useful in screening for choledocholithiasis during laparoscopic cholecystectomy. Following concerns regarding the "learning curve" and accuracy associated with the adoption of this user-dependent technology, we have prospectively evaluated a commercially available 90 degrees sector scanning laparoscopic ultrasound probe during elective laparoscopic cholecystectomy. Laparoscopic ultrasonography was performed in 60 patients and identified common duct stones in nine patients (one "false positive" and "one false negative"), and previously unsuspected duct stones were defined in three out of four patients. The gallbladder and portal vein were constantly defined anatomical landmarks throughout the study, whereas the suprapancreatic bile duct, intrapancreatic bile duct, and pancreatic duct were identified in 100%, 80%, and 85% of patients in the third consecutive group of 20 patients examined. Laparoscopic ultrasonography has the potential to accurately identify common duct stones during laparoscopic cholecystectomy and thereby implement a policy of "superselective" operative cholangiography. However, adequate training for surgeons unfamiliar with this technology is recommended.

Cholangiography↗
PubMed1994

Superior staging of liver tumors with laparoscopy and laparoscopic ultrasound.

OBJECTIVE: The authors describe the technique of staging laparoscopy with laparoscopic contact ultrasonography in the preoperative assessment of patients with liver tumors, and assess its impact on the selection of patients for hepatic resection with curative intent. SUMMARY BACKGROUND DATA: Laparoscopy may be useful in the selection of patients with a variety of intra-abdominal malignancies for operative intervention. Laparoscopic ultrasonography is a new technique that combines the principles of high resolution intraoperative contact ultrasound with those of the laparoscopic examination, and thus, allows the laparoscopist to perform detailed assessment of the liver. METHODS: This study analyzes a cohort of 50 consecutive patients who were diagnosed as having potentially resectable liver tumors, and in whom staging laparoscopy was successfully undertaken. Laparoscopic ultrasonography was performed in 43 patients, and the impact of the ensuing findings on the decision to proceed to operative assessment of resectability is examined. The resectability rate in those patients assessed laparoscopically and subsequently submitted to laparotomy is compared with a preceding group of patients in whom no laparoscopic assessment was performed. RESULTS: Laparoscopy demonstrated factors precluding curative resection in 23 patients (46%). Laparoscopic ultrasonography identified liver tumors not visible during laparoscopy in 14 patients (33%), and provided staging information in addition to that derived from laparoscopy alone in 18/43 patients (42%). The resectability rate was significantly higher among those patients undergoing laparoscopic staging (93%) compared with those in whom operative assessment was undertaken without laparoscopy (58%). CONCLUSIONS: Staging laparoscopy with laparoscopic ultrasonography optimizes patient selection for liver resection with curative intent.

Adult↗
PubMed1994

Clinical experience with sector scan and linear array ultrasound probes in laparoscopic surgery.

Laparoscopic ultrasonography combines the advantages of diagnostic laparoscopy and intraoperative contact ultrasonography. The early prototypes were based on the linear array intraoperative ultrasound transducer, which provided the hepatobiliary surgeon with detailed information on the hepatic and pancreatic tumour in addition to its relationship with the associated vasculature. The laparoscopic linear array probes provide similar information in patients submitted to diagnostic laparoscopy and provide the surgeon with rectilinear images that are easy to interpret. Laparoscopic sector scanning probes are now available and have the advantage of requiring only a small area of contact to produce a pie-shaped scan of the area of interest. Such images may be more difficult to orientate, but end viewing probes enable rapid changes in image direction when rotated and are probably the probe of choice in the detection of choledocholithiasis. At the present time, the laparoscopic ultrasonographer may have need of both probes to enable adequate evaluation of intraabdominal pathology. Technological advances will almost certainly provide more versatile ultrasound systems that will confirm the place of laparoscopic ultrasonography as a valuable investigative tool during laparoscopic procedures.

Cholecystectomy, Laparoscopic↗
PubMed1993

Abdominal aortic aneurysm in the elderly.

Thirty-five patients over the age of 80 years underwent surgery for abdominal aortic aneurysm between January 1985 and December 1990. Of these, 25 had surgery for ruptured aneurysm (mortality rate 56 per cent) and ten had surgery for symptomatic or asymptomatic aneurysm (mortality rate zero). The mortality rate for patients with rupture aged over 80 years was considerably greater than that for those under 80 years of age (56 versus 36 per cent). The mortality rate in the elderly population was zero for elective surgery but in those under 80 years it was 5 per cent. During the study period a prospective analysis of all referrals with aortic aneurysm was carried out, whether or not they underwent surgery and whether or not they were admitted to hospital. The ratio of patients accepted for operation to those not accepted for operation was 92:59 (1.56:1) in the under 80-year-old age group and 12:34 (0.35:1) in those aged over 80 years.

Age Factors↗
PubMed1993

Acute thrombosis of the non-aneurysmal abdominal aorta.

Fourteen patients admitted over a 9 year period with acute thrombotic occlusion of the non-aneurysmal abdominal aorta have been reviewed. Twelve patients underwent aortic bifurcation graft reconstruction, one thromboendarterectomy alone, and one a re-entry operation for dissection. Two patients (14%) died in the perioperative period. The mean postoperative survival of the remaining patients is to date 55 (range 4-93) months with a mean follow-up period of 69 (range 18-100) months. The results indicate these patients should be treated aggressively by early reconstructive surgery in the expectation that the majority will survive their operation and gain a useful extension to their lives.

Adult↗
PubMed1993

Needle track seeding of primary and secondary liver carcinoma after percutaneous liver biopsy.

Seeding of tumour in the needle track following percutaneous needle biopsy of liver neoplasms is rarely reported. We describe two such cases following the needle biopsy of an hepatocellular carcinoma and secondary colorectal carcinoma respectively. The risk of needle track recurrence of liver tumours should not be regarded as insignificant. The diagnosis of liver neoplasms may be achieved by non-invasive modalities, and their needle biopsy should be reserved for cases not amenable to surgical resection.

Adenocarcinoma↗
PubMed1993

An audit of trends and current practice of carotid endarterectomy in Edinburgh (1975-1990).

Changes in the patient population and trends in management were studied for 260 consecutive carotid endarterectomies performed during the periods 1975-1982 and 1983-1990. A 43% increase was observed in the number of operations (from 107 to 153), an 81% increase taking into account patients randomized to medical treatment in the European Carotid Surgery Trial. There were significant reductions in patients continuing to smoke (79 to 60%, P = 0.001), in those with systolic hypertension (21 to 11%, P = 0.018) and diastolic hypertension (26 to 12%, P = 0.002), and in those with asymptomatic carotid lesions (8 to 2%, P = 0.031). There were significant increases in the proportion of patients with strokes presenting with a residual neurological deficit (40 to 66%, P = 0.024), and in those with ocular symptoms (30 to 50%, P = 0.001) and with stenoses greater than 50% (58 to 71%, P = 0.018). This study suggests a trend for a higher risk population with more severe carotid disease. In the light of results of clinical trials, further evolution of patient selection is likely to occur and should be taken into account when evaluating the risk of carotid endarterectomy.

Adult↗
PubMed1993

Above-knee femoropopliteal bypass grafts and the consequences of graft failure.

In all, 290 femoral to above-knee popliteal artery bypasses were performed between January 1983 and September 1991. PTFE grafts were used in 113 cases (39%) and vein grafts in 177 (61%) (reversed in 146 cases and in situ in 31). Patients were followed up for a median time of 20 months. The 2-, 4- and 6-year patency rates for vein and PTFE grafts were 70%, 62% and 57%, respectively, compared with 58%, 46% and 41% (no statistical difference in survival curves, P = 0.2). The 2-, 4- and 6-year limb salvage rates were 82%, 78% and 62% compared with 75%, 64% and 58% (no statistical difference in survival curves, P = 0.6). A total of 99 grafts occluded during follow-up (45 PTFE and 54 vein grafts). Major amputation was required in 63 limbs; below-knee in 37 limbs (59%), and above-knee in 26 limbs (41%). There was no statistical difference in the amputation level with respect to the graft type. Final healing at the below-knee level was achieved in 23 of 35 (66%) failed vein grafts and in 14 of 28 (50%) failed PTFE grafts.

Adult↗
PubMed1992

Liver trauma: a 10-year experience.

The management of 73 patients with liver trauma (58 male, 15 female; mean age 30 (range 6-68) years) presenting from January 1980 to August 1990 is reviewed. There were 29 cases of penetrating injury and 44 of blunt trauma. Seven patients were successfully managed without operation (five with blunt injury) and were discharged after a mean hospital stay of 8 days. Fifty-one cases were classified as simple injuries (grade I or II) and were managed by suture (with or without drainage) or required no intervention, with three deaths. Fifteen cases were classified as complex injuries (grade III or IV) and underwent one or more of the following: perihepatic packing, resectional debridement, hemihepatectomy and hepatotomy with direct suture ligation. Six of these patients died from uncontrolled haemorrhage. The continued use of suture for simple injuries and of resectional debridement and/or packing for complex injuries is supported. Judicious clinical assessment and radiological monitoring may reduce the number of unnecessary laparotomies.

Abdominal Injuries↗
PubMed1991

Wound compression pads are of no value after local anaesthetic breast biopsy.

In a randomised study of 120 patients undergoing breast biopsy, wound compression pads did not reduce the frequency of postoperative bruising or haematoma formation, and 12% of the 62 patients having pads had complaints regarding their use. Wound compression pads are of no value after local anaesthetic breast biopsy.

Anesthesia, Local↗
PubMedDate not supplied

Current status of surgery in colorectal metastases to the liver.

The prime role of hepatic resection in the management of colorectal cancer metastatic to the liver is firmly established. The evolution of surgical and anaesthetic techniques has dramatically reduced the morbidity and mortality of elective liver resection in the hands os specialist hepatobiliary surgical teams. At least a third of patients who undergo liver resection for colorectal metastases can expect to survive five years. Although only 10-20% of all patients presenting with colorectal liver metastases are suitable for surgery, novel strategies such as portal vein embolisation and downstaging chemotherapy promise to increase the proportion of eligible patients.

Colorectal Neoplasms↗