Biomedical subjects

P Gersbach

Publications and source records attributed to P Gersbach.

At least 19 recordsLinked to original sources

PubMed2006

[Management of critical limb ischemia].

Critical limb ischemia (CLI) is the leading cause of major leg amputation. Diabetes, smoking and end stage renal disease are the main risk factors for CLI. Despite their reduced survival rate, most CLI patients should be treated by surgical or endovascular arterial reconstruction, since amputation rate with conservative treatment alone is as high as 95% at 1 year in surviving patients with tissue loss, and can be reduced to 25% with successful reconstruction. When arterial reconstruction is impossible or fails, spinal cord stimulation also allows to avoid major amputation in up to 75% of precisely selected patients. Timely management and multidisciplinary approach are advised to reduce the risk of major amputation.

Humans↗

PubMed2005

[Surgical options for terminal heart failure].

Terminal heart failure can be the cause or the result of major dysfunctions of the organisms. Although, the outcome of the natural history is the same in both situations, it is of prime importance to differentiate the two, as only heart failure as the primary cause allows for successful mechanical circulatory support as bridge to transplantation or towards recovery. Various objective parameters allow for the establishment of the diagnosis of terminal heart failure despite optimal medical treatment. A cardiac index <2.0 l/min, and a mixed venous oxygen saturation <60%, in combination with progressive renal failure, should trigger a diagnostic work-up in order to identify cardiac defects that can be corrected or to list the patient for transplantation with/without mechanical circulatory support.

Assisted Circulation↗

PubMed2003

[The heart transplant in Lausanne from 1987 to 2003].

Since the availability of ciclosporine, the survival after heart transplantation has dramatically improved. We present our results since the beginning of our experience in 1987. We treated in the Lausanne University hospital, 150 patients for end-stage cardiac disease. Hundred and fifty-two transplantations were performed. The survival rate is comparable to the literature with 81% at one year, 70% at five year and 63 at ten year included the hospital mortality. We review the incidence of complications during the follow-up and report the modification in the management of these patients especially concerning the immunosuppression.

Adult↗

PubMed2003

Spinal cord stimulation in the treatment of non-reconstructable stable critical leg ischaemia: results of the European Peripheral Vascular Disease Outcome Study (SCS-EPOS).

OBJECTIVE: To determine the effect of spinal cord stimulation (SCS) on limb survival in patients with non-reconstructable critical leg ischaemia, and the value of patient selection on the basis of transcutaneous oxygen pressure (TcpO2) measurements and trial screening. DESIGN: A prospective, controlled, European multicentre study. METHODS: Non-reconstructable patients with stable critical leg ischaemia were divided into three groups. The SCS-Match group comprised patients with a baseline forefoot TcpO2 of < 30 mmHg and both sufficient pain relief and sufficient paraesthesia coverage (> 75%) after a test stimulation period of at least 72 h. If baseline TcpO2 was < 10 mmHg, the TcpO2 should have exceeded 20 mmHg after test stimulation. The SCS-Match group was compared with patients not meeting these criteria, who were treated either with SCS (SCS-No-Match) or without SCS (No-SCS). RESULTS: At baseline, the mean (+/- SD) supine TcpO2 was 14.9 +/- 8.3 mmHg in the SCS-Match group (n = 41), 11.3 +/- 13.3 mmHg in the SCS-No-Match group (n = 32) and 15.3 +/- 17.1 mmHg in the No-SCS group (n = 39). In the SCS-Match group a significant improvement in pain relief (p < 0.005) and TcpO2 (p < 0.001) was seen. After 12 months, cumulative limb survival of patients treated with SCS was significantly better than that of patients not treated with SCS (p < 0.03), and limb survival in the SCS-Match group was significantly higher (p < 0.03) than that in the SCS-No-Match and No-SCS groups (78, 55 and 45%, respectively). CONCLUSION: SCS treatment of non-reconstructable critical leg ischaemia provides a significantly better limb survival rate compared with conservative treatment. Patient selection based on TcpO2 and the results of trial screening further increase the probability of limb survival after SCS therapy.

Adult↗

PubMed2001

Early metabolic and splanchnic responses to enteral nutrition in postoperative cardiac surgery patients with circulatory compromise.

OBJECTIVES: To assess the hemodynamic and metabolic adaptations to enteral nutrition (EN) in patients with hemodynamic compromise. DESIGN AND SETTING: Prospective study in a university hospital surgical ICU, comparing baseline (fasted) with continuous EN condition. PATIENTS: Nine patients requiring hemodynamic support by catecholamines (dobutamine and/or norepinephrine) 1 day after cardiac surgery under cardiopulmonary bypass. INTERVENTION: Isoenergetic EN via a postpyloric tube while catecholamine treatment remained constant. Baseline (fasted) condition was compared to continuous EN condition. MEASUREMENTS AND MAIN RESULTS: Cardiac index (CI), mean arterial pressure (MAP), pulmonary and wedge pressures, indocyanine green (ICG) clearance, gastric tonometry, plasma glucose and insulin, and glucose turnover (6,62H2-glucose infusion) were determined repetitively every 60 min during 2 h of baseline fasting condition and 3 h of EN. During EN CI increased (from 2.9 +/- 0.5 to 3.3 +/- 0.5 l min-1 m-2), MAP decreased transiently (from 78 +/- 7 to 70 +/- 11 mmHg), ICG clearance increased (from 527 +/- 396 to 690 +/- 548 ml/min), and gastric tonometry remained unchanged, while there were increases in glucose (158 +/- 23 to 216 +/- 62 mg/dl), insulin (29 +/- 23 to 181 +/- 200 mU/l), and glucose rate of appearance (2.4 +/- 0.2 to 3.3 +/- 0.2 mg min-1 kg-1). CONCLUSIONS: The introduction of EN in these postoperative patients increased CI and splanchnic blood flow, while the metabolic response indicated that nutrients were utilized. These preliminary results suggest that the hemodynamic response to early EN may be adequate after cardiac surgery even in patients requiring inotropes.

Adaptation, Physiological↗

PubMed2001

Active cooling during open repair of thoraco-abdominal aortic aneurysms improves outcome.

OBJECTIVE: Evaluate impact of active cooling with partial cardiopulmonary bypass (CPB) and low systemic heparinization during open repair of thoracoabdoninal aortic aneurysms. METHODS: Prospective analysis of 100 consecutive patients undergoing surgical repair of thoracoabdominal aortic aneurysms. Partial CPB and normothermic (36 degrees C) or hypothermic (29 degrees C) perfusion was selected in accordance to the surgeons preference. In the hypothermic group, aortic cross clamp was applied when the target temperature of the venous blood was achieved and rewarming was started after declamping. RESULTS: 52/100 patients (62.2+/-10.9 years) received normothermic and 48/100 patients hypothermic perfusion (63.8+/-10.6 years: NS). Emergent procedures accounted for 18/52 (35%) with normothermia vs. 21/48 (44%: NS) with hypothermia. The number of aortic segments (eight = maximum including arch and bifurcation) replaced was 3.9+/-1.5 with normothermia vs. 4.1+/-1.5 with hypothermia (NS); Crawford type II aneurysms accounted for 21/52 patients (40%) for normothermia vs. 20/48 (42%:NS) for hypothermia. Total clamp time was 38+/-21 min with normothermia vs. 47+/-28 min with hypothermia (P=0.05). Pump time was 55+/-28 min with normothermia vs. 84+/-34 min with hypothermia (P=0.001). Mortality at 30 days was 8/52 patients (15%) with normothermia vs. 2/48 (4%) with hypothermia (P=0.06; odds ratio = 4.1). Parapareses/plegias occurred in 4/52 patients (8%) with normothermia vs. 4/48 (8%) with hypothermia (NS). Revisions for bleeding were required in 4/52 patients (8%) with normothermia vs. 2/48 patients (4%) with hypothermia (P=0.38). Revisions for distal vascular problems were necessary in 5/52 patients (10%) with normothermia vs. 2/48 (4%) with hypothermia (P=0.25). Freedom from death, paraplegia, and surgical revision was 89.9% with normothermia vs. 94.8% with hypothermia (P=0.04; odds ratio 2.0). CONCLUSIONS: Active cooling during repair of thoracoabdominal aortic aneurysms allows for longer cross-clamp times, more complex repairs and improves outcome.

Aged↗

PubMed2001

Beating heart coronary artery surgery: is sternotomy a suitable alternative to minimal invasive technique?

OBJECTIVES: To evidence the respective advantages and drawbacks of minimal invasive-thoracotomy (MIDCAB) and off-pump sternotomy (OPCAB) coronary bypass techniques. METHODS: The perioperative and mid-term (3 months) results of the first 31 MIDCABs and 39 OPCABs performed by a single experienced coronary surgeon (F.S.) were compared. Differences were assessed by two-tailed chi-square or unpaired t-test, and significance assumed for P-values < or =0.05. RESULTS: Groups were widely comparable. There were no in-hospital deaths nor permanent neurologic events. OPCAB patients received more anastomoses (mean 1.09/patient vs. 1.89/patient, P<0.001) during a shorter coronary occlusion period (26.1+/-8 vs. 16.6+/-4.5min, P<0.001), whilst immediate extubation prevailed in MIDCABs (22/31 vs. 17/39, P<0.05). Significant complications occurred in seven MIDCABs vs. none in OPCABs (P<0.01). Other in-hospital parameters were similar. Controls at 3 months evidenced more residual discomfort among MIDCAB patients (14/30 vs. 7/39, P<0.05). CONCLUSIONS: Differences in early complication rates may be due to a learning effect. However, OPCAB allows us to implant more grafts and is more comfortable for both patient and surgeon. These advantages may well counterbalance the cosmetic benefits of MIDCAB procedures.

Aged↗

PubMed2000

Effects of cardiogenic shock on lactate and glucose metabolism after heart surgery.

BACKGROUND: Hyperlactatemia is a prominent feature of cardiogenic shock. It can be attributed to increased tissue production of lactate related to dysoxia and to impaired utilization of lactate caused by liver and tissue underperfusion. The aim of this prospective observational study was to determine the relative importance of these mechanisms during cardiogenic shock. PATIENTS: Two groups of subjects were compared: seven cardiac surgery patients with postoperative cardiogenic shock and seven healthy volunteers. METHODS: Lactate metabolism was assessed by using two independent methods: a) a pharmacokinetic approach based on lactate plasma level decay after the infusion of 2.5 mmol x kg(-1) of sodium lactate; and b) an isotope dilution technique for which the transformation of [13C]lactate into [13C]glucose and 13CO2 was measured. Glucose turnover was determined using 6,62H2-glucose. RESULTS: All patients suffered from profound shock requiring high doses of inotropes and vasopressors. Mean arterial lactate amounted to 7.8 +/- 3.4 mmol x L(-1) and mean pH to 7.25 +/- 0.07. Lactate clearance was not different in the patients and controls (7.8 +/- 3.4 vs. 10.3 +/- 2.1 mL x kg(-1) x min(-1)). By contrast, lactate production was markedly enhanced in the patients (33.6 +/- 16.4 vs. 9.6 +/- 2.2 micromol x kg(-1) x min(-1); p < .01). Exogenous [13C]lactate oxidation was not different (107 +/- 37 vs. 103 +/- 4 mmol), and transformation of [13C]lactate into [13C]glucose was not different (20.0 +/- 13.7 vs. 15.2% +/- 6.0% of exogenous lactate). Endogenous glucose production was markedly increased in the patients (1.95 +/- 0.26 vs. 5.3 +/- 3.0 mg x kg(-1) x min(-1); p < .05 [10.8 +/- 1.4 vs. 29.4 +/- 16.7 micromol x kg(-1) x min(-1)]), whereas net carbohydrate oxidation was not different (1.7 +/- 0.5 vs. 1.3 +/- 0.3 mg x kg(-1) x min(-1) [9.4 +/- 2.8 vs. 7.2 +/- 1.7 micromol x kg(-1) x min(-1)]). CONCLUSIONS: Hyperlactatemia in early postoperative cardiogenic shock was mainly related to increased tissue lactate production, whereas alterations of lactate utilization played only a minor role. Patients had hyperglycemia and increased nonoxidative glucose disposal, suggesting that glucose-induced stimulation of tissue glucose uptake and glycolysis may contribute significantly to hyperlactatemia.

Acidosis, Lactic↗

PubMed1997

Discriminative microcirculatory screening of patients with refractory limb ischaemia for dorsal column stimulation.

OBJECTIVES: (1) To determine the proportion of patients with critical limb ischaemia refractory to invasive treatment that can be successfully treated by dorsal column stimulation (DCS), and (2) to identify potential responders to DCS by a simple test that is sufficiently predictive to limit the need for a prolonged trial stimulation period. PATIENTS AND METHODS: Twenty patients with chronic limb-threatening ischaemia were assessed by a battery of macro- and microcirculatory tests and a DCS trial of 1 week. Favourable response during the trial determined selection for long-term stimulation. RESULTS: During a mean observation period of 14 months, limb salvage rate (LSR) was 63% overall and 83% among patients selected after a favourable trial. Of the tests performed preoperatively, digital subtraction angiography, Doppler assessment, oscillometry, capillaroscopy, foot temperature, and transcutaneous partial pressure of oxygen (tcpO2) in the supine or sitting position did not adequately predict DCS response. The supine-sitting tcpO2 gradient (delta tcpO2) was a good predictor of DCS outcome, with an 88% LSR when delta tcpO2 > 15 Torr, dropping to 12% when delta tcpO2 < or = 15 Torr. CONCLUSIONS: DCS is a rewarding therapeutic option in selected patients with critical limb ischaemia. delta tcpO2 appears to reliably predict response to DCS and may obviate trial stimulation in most cases.

Adult↗

PubMed1996

Congenital absence of the left pericardium with extreme intrathoracic displacement of the heart. Case report and review of the literature.

Large pericardial defects are exceptional and difficult to diagnose. A 62-year-old man underwent elective coronary surgery which was seriously complicated by the unexpected intrapleural position of the heart due to the absence of a large amount of pericardium on the left. It appeared retrospectively that the patient had presented typical signs of the malformation and these are described in detail.

Diagnosis, Differential↗

PubMed1996

Intraoperative internal mammary artery transit-time flow measurements: comparative evaluation of two surgical pedicle preparation techniques.

OBJECTS: Myocardial revascularization is performed preferentially with internal mammary artery grafts. Pedicle preparation and pharmacologic vasodilatory treatment vary greatly. Objective measurements are difficult since peripheral and later coronary vascular resistance and possible competitive flow of the native bypassed coronary artery will influence the results significantly. Our objectives were: (1) measurement of internal mammary artery graft flow with the transit-time flow technique; (2) comparison of two surgical take-down techniques (skeletonizing vs standard pedicle preparation); (3) quantitation of transit-time flow compared to the free pedicle flow and (4) the vasodilatory effect of papaverine on internal mammary artery flow. METHOD: Consecutive elective cases of coronary artery bypass grafting, performed by two surgeons using routinely either skeletonizing of the internal mammary artery (group A, n = 10) or classical pedicle preparation technique (group B, n = 10), were studied prospectively. Anesthesia, cardiopulmonary bypass and operative data were otherwise comparable; likewise, hemodynamic parameters showed no statistical differences between the two groups. Transit-time flow (CardioMed, Medi-Stim, Norway) was measured at the following time points: beginning (1) and end of take-down (2); after papaverine soaking: before (3) and on cardiopulmonary bypass (4); free flow into a beaker (5); after anastomosis; on (6) and off cardiopulmonary bypass (7). RESULTS: Measurement of mean flow showed the following results: (1) severe vasoconstruction of the internal mammary artery was detected in both groups regardless of the preparation technique (occurring earlier in group A); (2) papaverine soaking caused a moderate flow increase (up to 40%); (3) with corresponding cardiopulmonary bypass flow (4.4 vs. 4.1 l/min in group B) a higher free flow in group A was evident (67.7 vs. 50.7 ml/min); (4) after coronary grafting, transit-time flow showed no significant differences between the two groups and (5) using a 3 mm probe, a linear correlation was demonstrated between transit-time flow and simultaneously measured free flow (r = 0.89). CONCLUSION: Intraoperative transit-time flow measurement is a reliable method for assessing internal mammary artery and coronary artery bypass flow; considering the simple technical application, the procedure may be regarded as a valuable instrument of quality control.

Blood Flow Velocity↗

PubMed1995

[Cardiac surgery in octogenarians].

37 patients aged 80 or over underwent cardiac surgery during an 11-year period. Operative indications included angina, dyspnea and syncope. The majority of patients (n = 32) had a left ventricular ejection fraction greater than 0.5. There were 28 aortic valve procedures, of which seven were combined with coronary artery bypass grafts (CABG), and 2 with mitral valve repair; in addition, 7 isolated CABG procedures and one isolated mitral valve repair were performed. 36-day mortality was 5.4% (2 patients); 9 patients died at a later date (2.5 to 118 months after surgery). The most frequent postoperative complications were atrial fibrillation, pulmonary infection or atelectasis, transient delirium and atrioventricular conduction disturbances. Mean hospital stay was 14.5 days. 1- and 5-year actuarial survival rates were 83% and 57%. In a control group of patients aged 60-69 matched for preoperative characteristics, there were no in-hospital fatalities and 1- and 5-year survival were, respectively, 100% and 82%. Among complications, only conduction disturbances and transient delirium were significantly more frequent in the octogenarian group. At follow-up, the proportion of severely symptomatic octogenarians had diminished to 24% from 84%. In conclusion, cardiac surgery can be performed on octagenarians with adequate myocardial reserve, exposing them to a perioperative mortality that is in the range of younger age groups while offering an equivalent prospect for functional improvement.

Age Factors↗

PubMed1995

Surgery for acute ascending aortic dissection: closed versus open distal aortic repair.

One hundred twelve consecutive patients with acute ascending aortic dissection and submitted to immediate surgery were retrospectively analyzed with regard to perioperative mortality and morbidity. The patients were divided into two groups according to whether distal aortic repair was carried out by the open procedure (using deep hypothermic circulatory arrest, group A: 68 patients) or by the closed technique (without circulatory arrest, group B: 44 patients). Patients' ages ranged from 24 to 78 years (mean 57.4 years). No significant difference was found between the two groups in terms of age and sex distribution. However, the prevalence in the extent of clinical and anatomical alterations was significantly higher in group A (hemodynamic instability, pericardial tamponade and neurological deficit). The duration of hypothermic circulatory arrest for group A patients averaged 25 min and ranged from 12 to 65 min. The overall perioperative mortality was 17% (19/112 patients); it was 20.6% (14/68) in group A and 11.4% (5/44) in group B; the difference was not statistically significant but consistent with a clear trend. The trend towards a higher mortality in group A mainly reflected the more severe and complex anatomical characteristics and could not be attributed to the circulatory arrest per se. The period of deep hypothermic circulatory arrest in the survivors (25 min) was similar to that of the group with lethal outcome (32 min). Among the non-lethal complications, however, group A patients more frequently showed clinical signs consistent with cerebral injury: apart from the transient symptoms suggestive in reversible diffuse cerebral damage, five patients in group A had a permanent focal neurological deficit (versus one patient in group B).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1994

Spinal cord stimulation for unreconstructible chronic limb ischaemia.

There is still a lack of prospective randomised studies; at the present we know of only one by Jivegard et al. on a relatively small number of 51 patients. Their results are encouraging, tissue loss being reduced significantly and a trend towards increased limb salvage. The results of ongoing Dutch and American studies are awaited. It has however been shown in convincing microcirculatory studies by Jacobs et al. and others that SCS has a positive effect. Wide clinical experience has also substantiated this; were this not the case it would be hard to understand why elaborate studies by Augustinsson, Meyerson and the prolific work of Linderoth should ever have been designed. Recent communications by Lo Gerfo and others have shown that it is important to visualise the arterial tree all the way down to the foot by selective angiography before pronouncing a leg as non-reconstructible. The 3- and 5-year patency results of femoro- and popliteo-pedal bypass surgery presented by Lo Gerfo are so extraordinary--albeit probably unreproducible by all vascular surgeons--that SCS must be restricted to the truly unoperable or unreconstructable cases of CLI. SCS therefore is definitely not meant to be an alternative to reconstructive techniques!(ABSTRACT TRUNCATED AT 250 WORDS)

Electric Stimulation Therapy↗

PubMed1993

In vitro autoradiographic and in vivo scintigraphic localization of somatostatin receptors in human lymphatic tissue.

Receptors for the neuropeptide somatostatin (SS) were evaluated in vitro and in vivo in various human lymphatic tissues, ie, thymus, spleen, and lymph nodes; thymic carcinoids and thymomas were also tested. The receptors were measured in vitro using receptor autoradiography on tissue sections incubated with the SS analog 125I-[Tyr3]-octreotide or 125I-[Leu8,D-Trp22,Tyr25]-SS-28. All tissues were SS-receptor positive for either radioligand, except the thymomas. In thymic tissue, the receptors were diffusely located in the medulla, presumably on epithelial cells. In the spleen, the red pulp was strongly labeled. In the lymph nodes, the germinal centers were preferentially labeled. In all tissues, the receptors were of high affinity (kd thymus, 0.84 nmol/L; kd spleen, 1.6 nmol/L; kd lymph node, 0.62 nmol/L) and specific for SS. Displacement by nanomolar concentrations of SS-14, SS-28, and octreotide was observed, as was guanosine triphosphate dependency. The in vivo visualization of somatostatin receptors was performed after injection of 111In-DTPA-octreotide and gamma-camera scintigraphy. The spleen, but not thymus or lymph nodes, were visualized. These data suggest an important role for SS in regulating immune functions through SS receptors in thymus, spleen, and lymph nodes. Furthermore, SS may regulate neuroendocrine functions in the thymus.

Adolescent↗

PubMed1993

Impending rupture of the ascending aorta due to giant cell arteritis.

Giant cell arteritis may occasionally lead to vessel perforation without previous dissection. At the level of the ascending aorta, however, such an event has been reported only three times. We report a fourth case of impending rupture of the ascending aorta due to a small and isolated lesion of giant cell arteritis. In contrast to previous reports, laboratory and clinical manifestations suggestive of giant cell arteritis were absent in this case so that the diagnosis could only be established on histologic examination of the operative specimen.

Aortic Rupture↗

PubMed1991

Major coagulation disorders when using aprotinin--observations on a case.

Intraoperative application of the proteinase inhibitor aprotinin allows to drastically reduce blood loss during and after cardiopulmonary bypass operation. The side effects of this therapy (if any) have not been systematically registered and a possible interaction with heparin is not excluded. Such an interaction seems to have occurred in one of our patients. He developed a resistance to heparin shortly after prophylactic administration of aprotinin and maintained it for about one hour after discontinuation of the aprotinin. Prophylactic and therapeutic implications of this observation are briefly exposed.

Aged↗

PubMed1991

[Recent instrumental developments in percutaneous transluminal angioplasty (PTA)].

In addition to the balloon-catheter for PTA a number of new devices have been developed in recent years. Among them the most outstanding are laser beam application, mechanical devices for recanalization and endoprostheses for stenting of the vessels. The initial fascination by laser technique in PTA has given way to a matter-of-fact appreciation of the method. Up to now no available laser system achieves better clinical results than conventional PTA in the long run. Although there is much potential in the laser principle, it still is to be regarded as experimental. As for mechanical devices the fast rotating Kensey-catheter has not been proven superior to balloon PTA in our hands neither to remove organized or fresh thrombotic occlusive matter. A slowly rotating catheter (Rotacs) facilitates primary recanalisation of long occlusions prior to balloon dilatation. Atherectomy by the Simpson-catheter provides samples for histological studies but is indicated only in special situations. Numerous other mechanical percutaneous endarterectomy devices are under development, but clinical long term evaluation is not yet available. Vascular stents - self expandable or balloon expandable systems - may serve to keep the newly dilated arterial lumen open and to prevent late recurrences. While in larger vessels such as iliac arteries or aorta good long-term results after insufficient PTA were shown, other indications are still experimental. For all of these newer technologies both their relative effectiveness and the extent to which they may compare with or complement balloon PTA remain to be determined.

Angioplasty, Balloon↗