Biomedical subjects

J M Porter

Publications and source records attributed to J M Porter.

At least 73 records · Page 4Linked to original sources

PubMed1998

Value of computed tomography in the evaluation of retroperitoneal organ injury in blunt abdominal trauma.

Computed tomography (CT) is widely used in the evaluation of blunt abdominal trauma. One of its purported advantages is in the evaluation of the retroperitoneum. This study was undertaken to determine the utility of CT in diagnosing retroperitoneal organ injury. A retrospective chart review of 466 stable patients with blunt abdominal trauma who received abdominal CT was conducted. Twelve percent of the patients had CT scans showing retroperitoneal organ injury. There were 58 total injuries, with the kidney being the most frequently injured organ. Twenty-four patients required laparotomy, confirming the CT diagnosis in 8 patients (7 renal and 1 pancreatic). Two duodenal injuries were found at laparotomy that had not been seen on CT scan. Fourteen percent of the patients with positive CT scans had a positive laparotomy, and of those, 38% were therapeutic. Five percent of the patients with positive scans had therapeutic laparotomies. These data infer that the utility of CT to define retroperitoneal organ injury is lower than previously suspected.

Abdominal Injuries↗

PubMed1998

Inferior epigastric artery pseudoaneurysm: a complication of paracentesis.

Two patients had inferior epigastric artery pseudoaneurysms after therapeutic paracentesis for ascites caused by portal hypertension. The first patient, a 62-year-old man, had a two-week history of left lower quadrant pain, tenderness, and nonpulsatile mass after a paracentesis for ascites. A left inferior epigastric artery pseudoaneurysm measuring 10 cm in diameter and 20 cm in length was diagnosed by means of Duplex ultrasound and arteriography. The patient was treated with percutaneous embolization, with successful thrombosis of the pseudoaneurysm. The second patient, a 33-year-old woman, had a six-week history of left lower quadrant pain, tenderness, and nonpulsatile mass after a paracentesis for ascites. Computerized tomography and arteriography showed a left inferior epigastric artery pseudoaneurysm, measuring 7 cm in diameter and 9 cm in length. The patient was treated with percutaneous embolization with successful thrombosis of the pseudoaneurysm. Both patients were discharged in good condition 2 days after embolization. Inferior epigastric artery pseudoaneurysm is a complication of paracentesis, and percutaneous embolization may be preferable to surgical repair in patients with chronic liver failure and portal hypertension.

Adult↗

PubMed1998

Prophylactic repair of renal artery stenosis is not justified in patients who require infrarenal aortic reconstruction.

PURPOSE: Simultaneous prophylactic repair of asymptomatic renal artery stenosis (ARAS) in patients who require infrarenal aortoiliac reconstruction is controversial. This study documents the natural history of ARAS in patients who require aortic reconstruction. METHODS: Two hundred patients who required aortic reconstruction from 1985 to 1990 for indications other than hypertension or renal salvage were identified. ARAS was not repaired. Preoperative angiograms were available for 171 of 200 patients and were reviewed for renal artery stenosis. Patients were assessed for atherosclerotic risk factors, survival, preoperative and follow-up blood pressure, serum creatinine level, antihypertensive medication usage, and need for dialysis. RESULTS: The mean duration of follow-up was 6.3 years. Twenty-four of 171 patients (14%) had preoperative unilateral 70% to 99% diameter reduction ARAS, and eight (5%) had bilateral 70% to 99% ARAS. Clinical features associated with > or =70% ARAS included coronary artery disease, increased age, and a diagnosis of hypertension (p < 0.05). Patients with > or =70% ARAS did not have a decreased 7-year survival rate (66% vs 84%; p = 0.10) but had higher systolic blood pressures (153 +/- 25 vs 138 +/- 30 mm Hg; p < 0.05) as well as increased numbers of antihypertensive medications at follow-up (1.1 +/- 0.2 vs 0.7 +/- 1; p < 0.05). The mean serum creatinine level (1.1 +/- 0.3 preoperative vs 1.4 +/- 0.8 mg/dl; p = NS) was not increased. One patient (0.58%) with polycystic kidney disease and minimal renal artery stenosis required dialysis. CONCLUSIONS: High-grade ARAS in patients who are undergoing infrarenal aortic reconstruction is associated at late follow-up with increased systolic blood pressure and a need for increased numbers of antihypertensive medications, but not decreased survival rate, dialysis dependence, or an increase in serum creatinine level. These data do not support renal artery repair in patients with ARAS who undergo infrarenal aortic reconstruction.

Aorta, Abdominal↗

PubMed1998

Interposition grafting for reoperation on the common femoral artery.

PURPOSE: This report details our experience with common femoral artery resection and Dacron interposition grafting in the management of vascular reoperations involving the common femoral artery. DESIGN: Retrospective review. SETTING: University teaching hospital. SUBJECTS: Consecutive reoperative patients who had common femoral artery interposition grafting for arteriosclerotic occlusive disease from 1986 to 1997. INTERVENTIONS: Common femoral artery resection and interposition grafting. MAIN OUTCOME MEASURES: Operative morbidity and mortality rates and long-term patency, limb salvage, patient survival, freedom-from-graft-infection, and freedom-from-reoperation rates. RESULTS: Ninety-nine common femoral arteries (16 bilateral) were resected and replaced with Dacron interposition grafts in 83 patients (50 male, 33 female; mean age, 65 years) who had had 237 previous ipsilateral common femoral artery operations (mean, 2.4 operations; range, 1-9 operations). Simultaneous infrainguinal bypass grafts were performed in 52 operations (53%), and 60 operations (61%) were performed in patients who had had previous ipsilateral proximal bypass grafts. Operative mortality was 2%, with a 14% rate of perioperative wound complications. Mean follow-up time was 22 months. One- and 3-year assisted primary patency rates for the interposition grafts were 90% and 77%, respectively. Both 1- and 3-year life-table-determined limb salvage rates were 95%. One- and 3-year life-table-determined freedom-from-reoperation rates were 74% and 43%, respectively. One- and 3-year life-table-determined freedom-from-infection rates were 99% and 92%, respectively. One- and 3-year life-table-determined survival rates were 82% and 73%, respectively. CONCLUSIONS: Common femoral artery resection and Dacron interposition grafting are safe, and they obviate many difficulties associated with reoperative common femoral artery surgery with satisfactory long-term results.

Adult↗

PubMed1998

Late clinical and hemodynamic sequelae of isolated calf vein thrombosis.

PURPOSE: Despite the frequent occurrence of isolated calf vein thrombosis (ICVT), little is known about the long-term clinical and hemodynamic sequelae of this condition. This study was conducted to determine late clinical symptoms and vascular laboratory abnormalities in patients after ICVT. METHODS: Of 146 patients in whom ICVT was documented by color flow duplex scanning between 1989 and 1994, 37 were reexamined. Data included history, physical examination, venous recovery time (VRT), and duplex valve closure time (DVCT). A control group with no history of venous disease also underwent identical clinical and hemodynamic testing. RESULTS: Thirty-seven patients (18 male and 19 female) with a median age of 56 years (range, 22 to 76 years) were examined at a mean follow-up of 3.4 years (range, 2.2 to 5.8 years) after the diagnosis of ICVT in 39 extremities. Seventeen subjects (34 extremities) were recruited as normal controls. Presenting symptoms at the time of ICVT included calf pain in 17 patients, calf swelling in seven, pain and swelling in seven, pulmonary symptoms in four, pulmonary symptoms and calf pain in one, and no symptoms in one. In the patients with ICVT, VRT was abnormal in 23% of extremities with ICVT and in 9% of extremities without ICVT. None of the extremities in the control group had an abnormal VRT (p < 0.05). DVCT was abnormal in one or more venous segments in 26% of extremities diagnosed with ICVT and in 6% of control extremities (p < 0.05). Follow-up clinical examination in patients with ICVT revealed 13 (35%) with reticular veins, 10 (27%) with varicose veins, two (5.4%) with edema, one (2.7%) with pigmentation and ulcer (contralateral extremity to ICVT with a previous history of proximal deep venous thrombosis), 13 (35%) with mild discomfort, and one (2.7%) with severe pain. All symptoms attributable to ICVT were mild in nature except in one patient who had severe pain and no physical or hemodynamic vascular laboratory abnormalities at follow-up. CONCLUSION: At an average of 3.4 years after ICVT, approximately one third of patients showed evidence of mild to moderate venous valvular insufficiency, but mostly in segments not involved with ICVT, and few had significant clinical symptoms attributable to venous disease.

Adult↗

PubMed1998

Patient recovery after infrainguinal bypass grafting for limb salvage.

PURPOSE: The outcome of infrainguinal bypass surgery for limb salvage has traditionally been assessed by graft patency rates, limb salvage rates, and patient survival rates. Recently, functional outcome of limb salvage surgery has been assessed by patient ambulatory status and independent living status. These assessments fail to consider the adverse long-term patient effects of delayed wound healing, episodes of recurrent ischemia, and need for repeat operations. An ideal result of infrainguinal bypass surgery for limb salvage includes an uncomplicated operation, elimination of ischemia, prompt wound healing, and rapid return to premorbid functional status without recurrence or repeat surgery. The present study was performed to determine how often this ideal result is actually achieved. METHODS: The records of 112 consecutive patients who underwent initial infrainguinal bypass surgery for limb salvage 5 to 7 years before the study were reviewed for operative complications, graft patency, limb salvage, survival, patient functional status, time to achieve wound healing, need for repeat operations, and recurrence of ischemia. RESULTS: The mean patient age was 66 years. The mean postoperative follow-up was 42 months (range, 0 to 100.1 months). After operation 99 patients (88%) lived independently at home and 103 (92%) were ambulatory. There were seven perioperative deaths (6.3%), and wound complications occurred in 27 patients (24%). By life table, the assisted primary graft patency and limb salvage rates of the index extremity 5 years after operation were 77% and 87%, respectively, and the patient survival rate was 49%. At last follow-up or death, 73% of the patients (72 of 99) who lived independently at home before the operation were still living independently at home, and 70% (72 of 103) of those who were ambulatory before the operation remained ambulatory. Wound (operative and ischemic) healing required a mean of 4.2 months (range, 0.4 to 48 months), and 25 patients (22%) had not achieved complete wound healing at the time of last follow-up or death. Repeat operations to maintain graft patency, treat wound complications, or treat recurrent or contralateral ischemia were required in 61 patients (54%; mean, 1.6 reoperations/patient), and 26 patients (23.2%) ultimately required major limb amputation of the index or contralateral extremity. Only 16 of 112 patients (14.3%) achieved the ideal surgical result of an uncomplicated operation with long-term symptom relief, maintenance of functional status, and no recurrence or repeat operations. CONCLUSIONS: Most patients who undergo infrainguinal bypass surgery for limb salvage require ongoing treatment and have persistent or recurrent symptoms until their death. A significant minority have major tissue loss despite successful initial surgery. Clinically important palliation is frequently achieved by bypass surgery, but ideal results are distinctly infrequent.

Activities of Daily Living↗

PubMed1998

Vascular surgery.

Explore the source record for details and available documents.

Angioplasty↗

PubMed1998

Musculoskeletal problems and driving in police officers.

The Occupational Health Department of a rural police force in the UK had concerns regarding sickness absence levels due to musculoskeletal problems, particularly in officers who drove as part of their job. It was decided to conduct an interview survey comparing two groups of police officers with differing levels of exposure to driving, recording sickness absence and prevalence data related due to musculoskeletal troubles. The results indicate that exposure to car driving, both in terms of distance and hours driven, had a significant effect on self-reported low back trouble. Officers whose job mainly involved driving also experienced more low back trouble over the last 12 months than those whose job primarily involved sitting (not driving), standing and lifting tasks. Police motorcyclists had significantly higher prevalence figures for reported shoulder trouble than police car drivers.

Adult↗

PubMed1998

In search of the optimal end points of resuscitation in trauma patients: a review.

Complete resuscitation from shock is one of the primary concerns of the surgeon taking care of injured patients. Traditionally, the return to normalcy of blood pressure, heart rate, and urine output has been the end point of resuscitation. Using these end points may leave a substantial number of patients, up to 50 to 85% in some series, in "compensated" shock, which if it persists may ultimately lead to the death of the patient. Because of this potential other end points are being used and include supernormal values for oxygen transport variables (cardiac index, oxygen delivery, and oxygen consumption), lactate, base deficit, and gastric intramucosal pH. We believe that the current data support the use of lactate, base deficit, and/or gastric intramucosal pH as the appropriate end points of resuscitation of trauma patients. The goal should be to correct one or all of three of these markers of tissue perfusion to normal within the initial 24 hours after injury.

Acidosis↗

PubMed1998

Intra-abdominal hypertension after life-threatening penetrating abdominal trauma: prophylaxis, incidence, and clinical relevance to gastric mucosal pH and abdominal compartment syndrome.

OBJECTIVE: To define the incidence, prophylaxis, and treatment of intra-abdominal hypertension (IAH) and its relevance to gut mucosal pH (pHi), multiorgan dysfunction syndrome, and the abdominal compartment syndrome (ACS). METHODS: Seventy patients in the SICU at a Level I trauma center (1992-1996) with life threatening penetrating abdominal trauma had intra-abdominal pressure estimated by bladder pressure. pHi was measured by gastric tonometry every 4 to 6 hours. IAH (intra-abdominal pressure> 25 cm of H2O) was treated by bedside or operating room laparotomy. RESULTS: Injury severity was comparable between patients who had mesh closure as prophylaxis for IAH (n = 45) and those who had fascial suture (n = 25). IAH was seen in 10 (22.2%) in the mesh group versus 13 (52%) in the fascial suture group (p = 0.012) for an overall incidence of 32.9%. Forty-two patients had pHi monitoring, and 11 of them had IAH. Of the 11 patients, eight patients (72.7%) had acidotic pHi (7.10 +/- 0.2) with IAH without exhibiting the classic signs of ACS. The pHi improved after abdominal decompression in six and none developed ACS. Only two patients with IAH and low pHi went on to develop ACS, despite abdominal decompression. Multiorgan dysfunction syndrome points and death were less in patients without IAH than those with IAH and in patients who had mesh closure. CONCLUSIONS: IAH is frequent after major abdominal trauma. It may cause gut mucosal acidosis at lower bladder pressures, long before the onset of clinical ACS. Uncorrected, it may lead to splanchnic hypoperfusion, ACS, distant organ failure, and death. Prophylactic mesh closure of the abdomen may facilitate the prevention and bedside treatment of IAH and reduce these complications.

Abdomen↗

PubMed1998

Upper extremity arterial disease: etiologic considerations and differential diagnosis.

Upper extremity ischemia is an unusual clinical entity. Using a careful history and physical examination, detailed vascular laboratory testing, serological tests, and occasionally arteriography, it is possible to determine the cause in most patients. Most patients presenting with upper extremity ischemia have small vessel disease that is not amenable to surgical treatment. The primary treatment of upper extremity ischemia remains cold avoidance, with pharmacological treatment added in a limited number of patients. A patient's long-term prognosis can be determined based on initial serological studies and the presence or absence of arterial obstruction. Patients with no serological or arterial abnormalities usually continue to have upper extremity ischemic symptoms, but these remain only a nuisance. Patients with either serological abnormalities or arterial obstruction have a mild to moderate risk of progressive symptoms. Those patients with combined serological abnormalities and arterial obstruction at presentation are most likely to have continued difficulties. A significant number of these patients, approximately 50%, are most symptomatic at the time of initial presentation and improve under follow-up.

Angiography↗

PubMed1998

Iatrogenic vascular trauma.

With the increasing performance of percutaneous transluminal angioplasty and insertion of an increasing number of intravascular devices, the size of arterial punctures has been increasing. A consistent minority of these procedures will result in vascular injuries requiring treatment. At the same time, the regionalized nature of trauma care in the United States has resulted in a large number of vascular surgeons who are exposed to vascular trauma only when iatrogenic. The most common injuries observed are caused by percutaneous vascular instrumentation and include hemorrhage and pseudoaneurysm that may compress adjacent structures, fistula, acute occlusion, and embolization. Injuries unique to balloon angioplasty/stenting include arterial rupture and dissection. Indwelling intravascular devices are another common source of iatrogenic vascular injury ranging from arterial rupture to thrombosis and embolization. Much less common injuries are observed in orthopedic and abdominal/laparoscopic operations but show reproducible causes/patterns. Finally, pediatric iatrogenic vascular trauma is relatively common because of the small size of the vasculature, but the natural history and management is markedly different from that in adults.

Arterial Occlusive Diseases↗

PubMed1997

Upper extremity ischemia from subclavian artery aneurysm caused by bony abnormalities of the thoracic outlet.

OBJECTIVE: To describe our experience with surgical therapy for upper extremity ischemia incident to emboli from aneurysms of the subclavian artery. DESIGN: Retrospective review case series. SETTING: Vascular surgery practice at a university hospital-based tertiary referral center. PATIENTS: All patients treated for upper extremity ischemia caused by embolism from a subclavian artery aneurysm from January 1, 1990, to July 31, 1996. INTERVENTION: All patients underwent detailed history and physical examination, screening for immunologic and hypercoaguable disorders, noninvasive vascular laboratory evaluation, and arteriography of the aortic arch in both arms and hands. Surgical treatment consisted of rib excision or fracture plating, aneurysm excision, and interposition vein grafting, with additional saphenous vein bypasses to brachial or forearm arteries as needed to provide uninterrupted circulation to the wrist. RESULTS: Twelve patients (6 males; mean age, 37 years) were treated. All had episodic upper extremity ischemia with an initial misdiagnosis of primary vasospastic disorder. Rest pain and/or ischemic ulceration developed in 3. Duration of symptoms before correct diagnosis averaged 7 months (range, 1-36 months). All patients had bony abnormalities of the thoracic outlet (8 cervical ribs, 3 abnormal first ribs, and 1 unstable clavicular fracture). All aneurysms contained intraluminal thrombus, and all patients had multiple ipsilateral distal arm, forearm, and/or hand arterial occlusions indicating chronic and repeated embolization. All patients underwent aneurysm excision and interposition vein grafting, with additional vein bypass to the brachial (3 patients) and/or forearm arteries (5 patients). Mean follow-up was 18 months (range, 2 weeks to 63 months). Eleven patients had complete symptomatic relief, and 1 patient improved. All subclavian interposition grafts remained patient. Two distal bypass grafts occluded in patients with preoperative arteriograms demonstrating no patient forearm arteries. There has been no limb loss. CONCLUSIONS: Hand ischemia caused by embolization from a subclavian artery aneurysm occurs in young patients without atherosclerosis and is frequently misdiagnosed as vasospasm. Despite advanced disease and multiple chronic distal arterial occlusions, surgical treatment by resection of bony abnormalities, aneurysm excision and grafting, and distal bypass grafting produces excellent results.

Adolescent↗

PubMed1997

Ability of ankle-brachial index to detect lower-extremity atherosclerotic disease progression.

BACKGROUND: Accurate determination of progression of lower-extremity arterial occlusive disease (LEAOD) is required for natural history studies and evaluation of therapies for atherosclerosis. OBJECTIVE: To determine if changes in the ankle-brachial index (ABI) correlated with progression of LEAOD as determined by arteriography or duplex scanning. DESIGN: In patients with prior suprainguinal or infrainguinal lower-extremity revascularization, progression of LEAOD in native arteries was determined by comparing a preoperative (baseline) arteriogram with late follow-up arteriography or duplex scanning. Superficial femoral and popliteal arteries were graded as having less than 50% stenosis, 50% to 99% stenosis, or as being occluded. Tibial arteries were graded as continuously patent or occluded. Operated and nonoperated extremities were included in the study. The baseline ABI was performed postoperatively and repeated at follow-up arteriography or duplex scanning. Progression of LEAOD by the ABI was defined as a decrease in the ABI of 0.15 or greater. Progression of LEAOD by imaging studies was defined as an increase in 1 category of stenosis. Extremities with suprasystolic pressures were excluded. SETTING: Tertiary vascular surgical service. EXTREMITIES AND PATIENTS: One hundred ninety-three extremities were studied in 114 patients during a mean follow-up of 3.3 years. RESULTS: Seventy-two lower extremities (37.3%) showed progression of atherosclerosis by late follow-up arteriography or duplex scanning. Using the imaging studies as the criterion standard, the ABI had 102 true negatives, 29 true positives, 42 false negatives, and 20 false positives (sensitivity, 41%; specificity, 84%; positive predictive value, 59%; negative predictive value, 71%; and accuracy, 68%) for determining the progression of LEAOD. CONCLUSIONS: The ABI is relatively insensitive in identifying the progression of LEAOD as demonstrated by the use of imaging studies. In studies of natural history or therapy for atherosclerosis, imaging studies should be used in preference to the ABI to evaluate the progression of LEAOD accurately.

Adult↗

PubMed1997

Ventricular perforation associated with central venous introducer-dilator systems.

PURPOSE: Cardiac perforation is a recognised complication of guidewire-introducer techniques. These two new cases of right ventricular perforation implicate the dilator-introducer: one directly and the other due to presumed guidewire buckling. CLINICAL FEATURES: An 85-yr-old man underwent right subclavian cannulation for triple-lumen and pulmonary artery (PA) catheter insertion before coronary artery surgery. Tachycardia (120 bpm) and hypotension (60/30 mmHg) evolved over the next 40 min and resolved with evacuation of 200 ml of clot from the pericardial sac. A ragged 4 mm laceration of the ventricular wall was localised and oversewn without further consequence. A 60-yr-old man with inferior vena caval thrombosis was scheduled for Greenfield filter insertion. The right internal jugular vein was cannulated using the guidewire-introducer technique. Introduction of the introducer-dilator system precipitated cardiovascular collapse. Resuscitation was unsuccessful and post-mortem revealed right ventricular perforation and pericardial tamponade. CONCLUSION: These cases suggest that shorter introducer-dilators would be safer and probably equally efficacious. The need for a high index of suspicion and rapid therapeutic intervention is also highlighted.

Aged↗

PubMed1997

Duplex ultrasonography in evaluation of splanchnic artery stenosis.

Duplex ultrasonography accurately identifies high-grade stenoses in the SMA. Analysis of velocity data reveals few false positives and virtually no false negatives in the determination of high-grade SMA stenosis by duplex scanning. We therefore utilize duplex scanning to perform early screening studies of patients with symptoms suggestive of chronic visceral ischemia. If the duplex findings are negative, we recommend evaluating for other sources of abdominal pain. If the findings are positive, prompt angiography is indicated. It is important to remember that although duplex scanning can identify mesenteric artery stenosis, it cannot diagnose intestinal ischemia. By establishing duplex scanning as a useful and accessible noninvasive screening tool, it is hoped that the time between onset of visceral ischemic symptoms and diagnosis of chronic visceral ischemia will be shortened significantly, potentially reducing the morbidity and mortality of the disease.

Blood Vessel Prosthesis↗

PubMed1997

Intra-abdominal hypertension and the abdominal compartment syndrome.

IAH causes multiple and profound physiologic abnormalities both within and outside the abdomen. IAP monitoring is easily performed by bladder measurements. Careful monitoring and prompt recognition and treatment of IAP are critical in patients after damage control surgery because IAH is extremely common in these patients. Use of mesh fascial prostheses at the initial celiotomy in high-risk patients may prevent the deleterious effects of IAH. IAH should be considered an earlier manifestation of ACS. Surgical intervention should be indicated by IAH and not delayed until ACS is clinically apparent.

Abdomen↗

PubMed1997

In vitro flow testing of glaucoma drainage devices.

OBJECTIVE: The study was intended to determine methods that could evaluate in vitro the flow characteristics of glaucoma drainage devices. DESIGN: Two test methods were used: (1) a gravity-driven flow test and (2) a syringe-pump-driven flow test. Eighteen devices, both valved and nonvalved, from 4 manufacturers were evaluated for their hydrodynamic resistance and the pressure at which the flow becomes 0. OUTCOME: Results show a wide variation in device performance, indicating a strong need for enhanced quality control procedures in the device manufacturing process. CONCLUSION: A gravity-driven flow test provides a reasonably quick test of both resistance and closing pressure, which might be useful as a manufacturing line test. The syringe-driven flow test requires more time but provides additional insight into device performance, and, therefore, might be useful as a design validation test.

Drainage↗