Polytetrafluoroethylene and bovine mesenterial vein grafts for hemodialysis access: a comparative study

PURPOSE

This study aimed to evaluate the safety and patency rate of bovine mesenterial vein grafts (BMVG) for vascular access (VA) in hemodialysis patients (HDP), compared to expanded polytetrafluorethylene (ePTFE grafts) over a mid- to long-term period.

METHODS

Patency and complication rate of 23 consecutive HDP with BMVG for VA were compared to a control group consisting of 23 similar HDP with ePTFE grafts. In both groups, the graft was placed preferably in a forearm loop configuration. The same surgeon performed all procedures. All patients were followed over a period of 4 yrs.

RESULTS

Graft placement was successful in all patients. Patency rates did not differ significantly in both groups. However, there were less severe complications in the BMVG group.

CONCLUSION

The BMVG is a viable alternative for HD access in patients where autologous construction is not possible, and should be given priority in patients with a failed ePTFE graft or high risk for infection.

Influence of naloxone on gastric emptying of solid meals, myoelectrical gastric activity and blood hormone levels in young healthy volunteers

There is considerable evidence that opioid mechanisms are involved in the mediation of pyloric motor responses that in turn regulate gastric emptying. The purpose of this randomized, placebo-controlled crossover study was to investigate the effect of naloxone on gastric emptying of a solid meal, gastric myoelectrical activity and the postprandial release of gastrointestinal peptides and neuropeptides in 20 healthy volunteers. Naloxone was administered as an intravenous bolus, followed by continuous infusion according to an intravenous dosing nomogram. Gastric emptying time was evaluated by scintigraphy and gastric myoelectrical activity was evaluated by cutaneous electrogastrography. Naloxone did not significantly alter gastric half-emptying time and postprandial dominant gastric electrical frequency compared with placebo. It also did not significantly change the plasma levels of several peptide hormones with the exception of neuropeptide Y, which was significantly increased (P = 0.001). In conclusion, in doses that influence human intestinal motility, naloxone had no effect on gastric motility and release of several peptide hormones in healthy male volunteers. The importance of the isolated increased neuropeptide Y plasma level needs further investigation.

Risk assessment in patients with ruptured abdominal aortic aneurysms

OBJECTIVES

Surgery of ruptured abdominal aortic aneurysms is associated with a high mortality rate, mostly related to multi-organ-failure after a prolonged intensive care therapy. In a retrospective study attempts are made to identify individual organ-dysfunction risk profiles influencing the outcome.

METHODS

Fifty seven patients (53 men, 4 women, mean age 71.8 +/- 8.8 years) with ruptured abdominal aortic aneurysms underwent graft replacement in a three year period. Fourty eight preoperative, 13 intraoperative and 34 postoperative variables were analyzed. A multi-organ dysfunction (MOD) score was used.

RESULTS

The perioperative mortality rate was 31%. Significance of pre-existing risk factors at admission was identified only for cardiovascular diseases. Multiple linear regression analysis indicated that hemoglobin < 90 g/l, systolic blood pressure < 80 mmHg and ECG signs of ischemia at admission are highly significant risk factors. Patients, who died later than 48 hours postoperatively, deceased mainly from MOD (93%) and required intensive care significantly longer than surviving patients (p < 0.0005). All patients with a MOD score > or = 4 died (n = 7). These patients required 26% of all ICU-days and 72% of the ICU-days of the nonsurvivors.

CONCLUSION

Patients with ruptured aortic aneurysms should not be excluded from treatment. However, a physiological scoring system after 48 h appears justifiable in order to decide on the appropriateness of continued ICU support.

[Assessment of intraoperative duplex sonography during carotid endarterectomy]

INTRODUCTION

Carotid endarterectomy (CEA) for prevention of strokes mandates a high amount of experience and a meticulous surgical technique. Intraoperative morphologic as well as hemodynamic monitoring of the endarterectomized arteries is rarely performed. The purpose of this study was to determine the value of intraoperative colour-coded-duplex-sonography to recognize eventual intraoperative technical problems that might result in serious cerebral damage.

METHODS

Prospective analysis of the medical data of all patients who underwent CEA for treatment of high-grade carotid stenosis between 1996 and 1999. Adequacy of the repair was assessed intraoperatively by duplexsonography.

RESULTS

Of 142 consecutive patients with a median age of 68 (43-84) years, 104 (73 %) were men and 38 (27 %) were women. 9 patients (6 %) had bilateral CEAs. Intraoperative duplexsonography revealed abnormalities during 11 (7 %) of 151 CEAs. 4 (3 %) were considered major and underwent immediate revision. There was one (0.7 %) temporary neurologic deficit (hyperperfusion syndrome) and 2 (1.3 %) cases of fatal intracerebral hemorrhage. 6 (4 %) postoperative surgical complications occurred, i. e. 3 cases of major wound hematoma (with revision) and 3 cases of temporary cranial nerve palsy. Median length of follow-up was 11 (3-35) months. No late neurologic event occurred during follow-up. 5 (3 %) patients developed asymptomatic restenosis.

DISCUSSION

Routine intraoperative duplexsonography is a valuable and reliable diagnostic tool to detect correctable technical problems during CEA that subsequently may lead to neurological deficits, fatal stroke or a high incidence of restenosis.

Häufigkeit, Klassifikation und Therapie der isolierten Beckenarterienaneurysmen

INTRODUCTION

Isolated iliac artery aneurysms (IAA) are rare. The rupture risk, however, is high and the diagnosis can be difficult. The aim of this study was to report the frequency, morphology and outcome of these lesions.

METHODS

Retrospective analysis of the medical data of all patients treated for IAA from 1990 to 1999.

RESULTS

Fifty-nine consecutive patients, 55 (93%) male and 4 (7%) female, were included in the study. The median age was 68 (48-86) years. During the same time period, 741 consecutive patients with aortoiliac aneurysms were treated; thus the frequency of IAA was 8%. The median diameter of the IAA was 7 (3-12) cm. Most patients had at least one risk factor. IAA were unilateral in 40 (68%) or bilateral in 19 (32%) patients and affected the common iliac artery in 25 (19%), the internal iliac artery in 11 (19%) and simultaneously the common and internal iliac artery in 21 (36%) patients. Additional involvement of the external iliac artery was noted in 2 (3%) patients. Thirty-six (61%) patients with IAA underwent elective treatment while 23 (39%) patients had to be treated on an emergency basis. Endovascular stent grafts were inserted in 2 patients. Overall mortality was 10% (n = 6), 2.8% (n = 1) in asymptomatic and 22% (n = 5) in symptomatic or ruptured IAA. Overall morbidity in this study was 30%. The median follow-up of the patients was 36 (2-120) months.

DISCUSSION

Surgical therapy in patients with asymptomatic IAA can be performed with a reasonable mortality. However, mortality and morbidity in patients with symptomatic or ruptured IAA remains high. Postoperative long-term results are excellent. The value of endovascular therapy for IAA has yet to be determined.

[Results of surgical therapy and classification of non-ruptured abdominal aortic aneurysms]

INTRODUCTION

Surgery for symptomatic aortic abdominal aneurysms (sAAA) is associated with an increased mortality and morbidity compared to asymptomatic aortic aneurysms (aAAA). With the advent of endovascular therapy, an alternative therapeutic modality has become available. Endovascular therapy, however, depends on certain morphologic criteria, whereas open surgery can be performed on any type of AAA. The purpose of this study was to analyse our data of surgical treatment of non ruptured AAA and to identify the amount of patients in whom endovascular therapy would have been possible.

METHODS

Retrospective analysis of the medical data of all patients operated upon non ruptured AAA in our department by 3 responsible vascular surgeons from 1995-1999.

RESULTS

225 consecutive patients with a median age of 65 (42-95) years were included in the study. There were 184 (82%) male and 41 (18%) female patients with 143 (63.5%) aAAA and 82 (36.5%) sAAA. Patients with sAAA underwent emergency aneurysm repair and had a significantly increased aneurysm diameter compared to the aAAA, who underwent elective surgical aneurysm repair (6.9 +/- 1.6 cm vs. 6 +/- 1.2 cm; p = 0.002). A total of 11 (4.9%) patients had an inflammatory AAA. Smoking was found to be the only significant increased preoperative risk factor in the group of sAAA compared to aAAA (91 vs. 35 patients; p = 0.008). Morbidity was significantly increased in the patients with sAAA compared to the aAAA (55% vs. 31.5%; p = 0.041) The mortality however did not differ significantly in the two groups (2 vs. 3 patients; p = 0.691). Considering morphological criteria of the AAA, endovascular therapy would have been possible in 59 (26%) patients. However, in 24 (11%) of the 59 patients, endovascular therapy was not feasible because of aortic kinking, heavy calcification of the aneurysm neck, a patent inferior mesenteric artery or atherosclerotic diseased iliac arteries. Consequently, only 35 (15%) patients would have qualified for an endovascular therapy.

DISCUSSION

Surgical therapy can be performed in patients with asymptomatic and symptomatic AAA with an equal low mortality. This finding underlines the fact, that surgical therapy still remains the standard therapy for AAA. In addition, in our study only a relative small amount of patients would have qualified for an endovascular therapy.

Ischaemia/reperfusion contributes to colonic injury following experimental aortic surgery

OBJECTIVES

ischaemia of the colon is an important complication of abdominal aortic aneurysm (AAA) repair. The aim of this animal study was to investigate the effect of sequential ischaemia and reperfusion on sigmoid mucosal pO2 and its association with local ET-1 release.

MATERIAL AND METHODS

twelve pigs underwent colonic ischaemia followed by complete reperfusion. Six other animals were sham controls. A Clark-type microcatheter was used for continuous mucosal pO2 measurements. Serial systemic and inferior mesenteric vein blood samples were obtained for determination of ET-1 concentration. Neutrophil extravasation was assessed by tissue myeloperoxidase (MPO) activity.

RESULTS

arterial occlusion was associated with a gradual decrease of mucosal pO2 and local release of ET-1. After restoration of blood flow, mucosal pO2 returned to near baseline values, whereas ET-1 reached its maximum concentration during the reperfusion period. MPO activity was significantly increased.

CONCLUSIONS

colonic ischaemia and reperfusion causes neutrophil extravasation and local ET-1.

Surgery for aortoiliac aneurysms in kidney transplant recipients

With the increase of long-term survivors following renal transplantation, aorto-iliac aneurysms requiring surgical management may be encountered more often. Our experience with temporary shunts for renal transplant protection during aorto-iliac aneurysm repair is presented along with a literature review of all cases on the subject. Three male patients with a median age of 56 (range 50-61) years were operated on for a dissecting aneurysm of the common iliac artery in one, respectively abdominal aortic aneurysm in the two remaining patients. All patients had impaired transplant function preoperatively with a median serum creatinine level of 167 (range 134-202) micromol/L and a median blood urea nitrogen concentration of 15 (range 9-23) pmol/L. The intra- and postoperative course was uneventful in all patients. Median postoperative serum creatinine level and blood urea nitrogen concentration were 135 (range 123-151) micromol/L and 10 (range 9-11) pmol/L, respectively. Aorto-iliac surgery in renal transplant recipients can be performed without transplant protection. However, in patients with a deteriorated transplant function or if a prolonged aortic cross-clamp time is anticipated, renal allograft protection measures may be beneficial to prevent possible ischemic damage.

[Rare, but severe complication of varicose vein surgery. Compartment syndrome]

The compartment syndrome is an extremely rare complication after varicose vein surgery. If the early symptoms are not recognized and a treatment is not performed immediately most patients lose sensomotory function. Three cases with compartment syndrome after varicose vein stripping were the reason to point out the anatomy and pathophysiology of this complication and to explain the surgical technique.

Cytokines in surgical trauma: cholecystectomy as an example

Interleukin-1 (IL-1), tumor necrosis factor and particularly IL-6 are potent mediators of the immune and acute phase response caused by surgery and trauma. Their production can be reduced by steroids, nonsteroidal anti-inflammatory agents, nitric oxide and anti-inflammatory cytokines such as IL-4, IL-10 and IL-13. Some of the benefits of minimal invasive surgery may be due to lower cytokine levels in these procedures compared to those of conventional surgery, although this is but one factor that should be taken into account. Therefore, all surgical procedures that cause a lower systemic cytokine response are to be favored if other effects and the side effects of the surgery are equal.

Treatment of ruptured abdominal aortic aneurysm, a permanent challenge or a waste of resources? Prediction of outcome using a multi-organ-dysfunction score

OBJECTIVES

in a retrospective study, attempts have been made to identify individual organ-dysfunction risk profiles influencing the outcome after surgery for ruptured abdominal aortic aneurysms.

METHODS

out of 235 patients undergoing graft replacement for abdominal aortic aneurysms, 57 (53 men, four women, mean age 72 years [s.d. 8.8]) were treated for ruptured aneurysms in a 3-year period. Forty-eight preoperative, 13 intraoperative and 34 postoperative variables were evaluated statistically. A simple multi-organ dysfunction (MOD) score was adopted.

RESULTS

the perioperative mortality was 32%. Three patients died intraoperatively, four within 48 h and 11 died later. A significant influence for pre-existing risk factors was identified only for cardiovascular diseases. Multiple linear-regression analysis indicated that a haemoglobin <90 g/l, systolic blood pressure <80 mmHg and ECG signs of ischaemia at admission were highly significant risk factors. The cause of death for patients, who died more than 48 h postoperatively, was mainly MOD. All patients with a MOD score >/=4 died (n=7). These patients required 27% of the intensive-care unit (ICU) days of all patients and 72% of the ICU days of the non-survivors.

CONCLUSION

patients with ruptured aortic aneurysms from treatment should not be excluded. However, a physiological scoring system after 48 h appears justifiable in order to decide on the appropriateness of continual ICU support.

Endoscopic measurement of pancreatic tissue perfusion in patients with chronic pancreatitis and control patients

BACKGROUND

Pancreatic blood flow is diminished in experimental models of acute and chronic pancreatitis. We attempted to develop a safe and reliable technique for its measurement in patients and to examine blood flow in patients with chronic pancreatitis and in control subjects.

METHOD

Pancreatic blood flow was measured using the hydrogen gas clearance technique and an endoscopically placed platinum ductal electrode. Pancreatic blood flow was measured in 12 patients with chronic pancreatitis diagnosed clinically and radiographically, and in 11 control patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) for non-pancreatic pathology.

RESULTS

Patients with chronic pancreatitis had a significantly lower pancreatic blood flow compared with control patients (51.5 versus 91.7 mL/min/100 gm, p < 0.01). With secretin stimulation pancreatic blood flow increased in two control patients, whereas this notable rise was not seen in three patients with chronic pancreatitis.

CONCLUSIONS

Measurement of pancreatic blood flow with an endoscopically placed electrode is relatively safe and simple to perform. The scarring and vascular fibrosis associated histologically with chronic pancreatitis is reflected in lower pancreatic blood flow.

Mural aortic thrombi: An important cause of peripheral embolization

PURPOSE

Arterial thromboembolism in patients with an unknown source of embolization is still associated with significant morbidity and mortality. The advent of transesophageal echocardiography (TEE) and magnetic resonance imaging (MRI) and the more frequent use of computed tomography (CT) have led to the identification of mural aortic thrombi (MAT) as a source of distal embolization in a much higher proportion of patients than previously appreciated. The incidence, diagnosis, and treatment of patients with MAT is reported.

METHODS

In a prospective study, from January 1996 to December 1998, 89 patients with acute embolic events underwent an extensive diagnostic workup, consisting of TEE, CT, or MRI, to detect the source of embolization. Patients in whom the heart (n = 51), occlusive aortoiliac disease (n = 16), or aortic aneurysms (n = 12) was identified as the source of embolization were excluded.

RESULTS

Five female and three male patients, with a median age of 63 years (range, 35 to 76 years), with bilateral or repetitive embolic events resulting from MAT were identified, representing 9% of all patients with arterial thrombembolism. All patients had several risk factors for atherosclerosis, but only one young patient had a single risk factor that promoted thrombosis. Successful percutaneous catheter aspiration embolectomy was performed in six patients. The remaining two patients underwent surgical thromboembolectomy. A below-knee amputation had to be performed in two patients, thus representing a morbidity of the primary treatment of 25%. MAT of equal value were detected in the ascending (n = 1) and thoracic aorta (n = 3) by means of TEE, CT, or MRI. MAT in the abdominal aorta (n = 4) were identified by means of CT and MRI. Surgical removal of MAT was performed in seven patients by means of graft replacement of the ascending aorta (n = 1), open thrombectomy of the descending aorta (n = 2), and thrombendarterectomy of the abdominal aorta (n = 4), without intraoperative or postoperative complications. No recurrence of MAT occurred during a median follow-up period of 13 months (range, 4 to 24 months).

CONCLUSION

MAT represent an important source of arterial thrombembolism. A diagnostic workup of the aorta, preferably by means of CT or MRI, should be performed in all patients in whom other sources of embolization have been ruled out. The ideal therapeutic approach to these patients still awaits prospective evaluation. However, based on our experience, MAT can be successfully treated with a definitive surgical procedure in selected patients, with low mortality and morbidity.

Effect of pancreaticojejunostomy on fibrosis, pancreatic blood flow, and interstitial pH in chronic pancreatitis: a feline model

OBJECTIVE

To study the relation between fibrosis, pancreatic blood flow (PMBF), interstitial pH (pHi), and the effects of pancreaticojejunostomy (PJ) in chronic pancreatitis.

BACKGROUND

Chronic pancreatitis is associated with low PMBF and pHi, suggesting the existence of underlying ischemia.

METHODS

In cats, the main pancreatic duct was partially obstructed and the animals were studied 2, 4, 6, and 8 weeks later. PJ was performed after 2 and 4 weeks of ductal obstruction and studied 4 weeks later. PMBF and pH were measured before and after stimulation with secretin and cholecystokinin. pHi was measured with microelectrodes, PMBF by hydrogen gas clearance. Histologic analysis of the pancreas with Sirius red (collagen stain) and fast green FCF (noncollagen protein) stains allowed semiquantitative analysis of the ratio between collagen and total protein (C/TP).

RESULTS

With the evolution of chronic pancreatitis, there is a progressive increase in the collagen content and C/TP ratio, a reduction in basal PMBF and pHi, and loss of the normal response to stimulation. Early PJ restores collagen content, C/TP ratio, and basal and stimulated PMBF and pHi to normal. PJ performed in established CP returns the C/TP ratio to normal, improves basal PMBF, and restores the normal hyperemic response to secretion. Basal pHi is improved and the "acid tide" associated with secretin returns, but there is still no response to cholecystokinin.

CONCLUSIONS

Pancreaticojejunostomy restores the elevated collagen and C/TP ratio to normal and reverses the ischemia present in CP. The authors speculate that restoration of PMBF and its normal response to stimulation allows "regeneration" and restoration of secretory function.

[Cryopreserved arterial homografts. A treatment alternative for infected vascular reconstructions]

Deep wound infection or prosthetic vascular graft infection is one of the most challenging complications in vascular surgery with a substantial early and late morbidity and mortality. Surgical treatment usually consists of complete removal of infected vessels or prosthetic vascular grafts followed by extraanatomic bypass procedures. However, this method is associated with significant mortality and amputation rates. Herein, we report two patients with deep wound and prosthetic vascular graft infection who underwent successful in situ reconstruction with cryopreserved arterial homografts. Although the long-term results are missing, this approach may offer a possible treatment alternative for this potentially life-threatening complication.

Selective use of temporary intravascular shunts in coincident vascular and orthopedic upper and lower limb trauma

BACKGROUND

Combined vascular and skeletal injuries are associated with a high limb loss rate. One of the major factors resulting in amputation is frequently because the allowable warm ischemia time for skeletal muscle is exceeded before adequate revascularization.

METHODS

Temporary vascular shunting has been used in selected patients with complete ischemia to minimize the ischemic time of the injured limb, allowing identification of vital structures, thorough debridement, and rigid internal fixation before definitive vascular repair.

RESULTS

Five male and two female patients with a median age of 46 years (range, 27-76 years) admitted with combined orthopedic and vascular injuries of the upper limbs in four and the lower limbs in three patients underwent primary vascular shunting. The median ischemic time for all patients was 180 minutes (range, 120-210 minutes). Shunt insertion was accomplished in all cases within 30 minutes. Median dwell time for the shunt was 185 minutes (range, 90-390 minutes). No shunt-related complications or limb loss occurred. During follow-up ranging from 2 to 24 months, all vascular repairs remained patent. All fractures healed primarily, except for one patient in whom a necrosis of the humeral head occurred. Five patients had an excellent and two patients a good result.

CONCLUSION

Initial temporary vascular shunting in selected patients with combined skeletal and vascular injury of the upper or lower limb may reduce the complications resulting from prolonged ischemia and permits an unhurried and reasonable sequence of treatment.

Microcirculation in chronic alcoholic pancreatitis: a laser Doppler flow study

Experimental chronic pancreatitis is associated with microcirculatory disturbances but can also be induced or aggravated by perfusion changes. Microcirculatory alterations in human chronic pancreatitis are poorly defined. In this clinical study we investigated pancreatic microcirculation in the normal human pancreas and in chronic pancreatitis by laser Doppler flowmetry. Laparotomy was performed on 13 patients with nonpancreatic disease and on nine patients with chronic alcoholic pancreatitis for pancreatic head resection. Blood flow was measured over the pancreatic head, the uncinate process, over the mesenteric vein, the pancreatic corpus, and over the pancreatic tail by laser Doppler flowmetry. Blood flow was highest in the head of a normal pancreas with a mean of 436 +/- 34 perfusion units (PU), 399 +/- 43 PU in the uncinate process, 286 +/- 30 PU in the pancreatic corpus, and 351 +/- 46 PU in the tail of the pancreas. In the normal pancreas, lowest blood flow was measured over the mesenteric vein (228 +/- 23 PU). In chronic pancreatitis, blood flow in the pancreas was significantly decreased across the whole pancreas (p < 0.01). Furthermore flow-wave pattern was altered in chronic pancreatitis as compared with the normal pancreas. The normal human pancreas has a spatial variation in blood flow, correlating with the pancreatic arterial blood supply. In the chronically inflamed human pancreas, blood flow is significantly diminished, with a lower flow toward the pancreatic head.

Acute hemorrhage in chronic pancreatitis: diagnosis and treatment options including superselective microcoil embolization

Acute hemorrhage in the course of chronic pancreatitis is the most serious and challenging complication, and its treatment has been the subject of controversy for years. We relate our experience in the management of this complication by superselective microcoil embolization. Five patients with acute hemorrhage resulting from chronic pancreatitis between 1994 and 1997 were included in this study. All patients were men with a median age of 44 years (range, 29-59 years). The bleeding occurred into a pseudocyst in all patients, with the splenic artery as feeding vessel. In all instances, the bleeding was successfully controlled by superselective microcoil embolization. Two patients underwent subsequent uneventful elective pseudocystojejunostomy. There was no mortality or morbidity, and no rebleeding occurred during a median follow-up of 22 months (range, 8-36 months). In appropriate patients, diagnostic angiography and superselective microcoil embolization may obviate the need for emergency surgery and should be considered as treatment alternative.

Feline model of chronic obstructive pancreatitis: effects of acute pancreatic duct decompression on blood flow and interstitial pH

BACKGROUND

The mechanism by which duct decompression (DD) relieves pain in patients with chronic pancreatitis (CP) is unknown. CP is associated with increased tissue pressure (IP), low pancreatic microvascular blood flow (PMBF), and interstitial pH (pH(I)). The aims of this study were to examine the effects of acute DD on PMBF, increased IP, and pH(I) in cats with CP.

METHODS

The main pancreatic duct was partially obstructed. At 6 weeks PMBF (ml/min/100g H2 gas clearance), IP (mmHg needle electrode), and pH(I) (microelectrode) were measured before and after secretin stimulation. The duct was then opened, and the studies were repeated.

RESULTS

PMBF normally increased with secretin stimulation (118 +/- 20 versus 271 +/- 52, P < 0.05). IP was unaltered, and pH(I) decreased as hydrogen ions produced during bicarbonate secretion were dissipated (7.41 +/- 0.01 versus 7.38 +/- 0.01, P < 0.05). In CP, basal PMBF was lower than normal (51 +/- 6 versus 118 +/- 20, P < 0.05) and decreased with stimulation (51 +/- 3.5 versus 31 +/- 3.5, P < 0.05). Basal pancreatic IP was increased (3.47 +/- 0.7 versus 0.05 +/- 0.3, P < 0.05) and increased further with secretory stimulation (3.47 +/- 0.7 versus 4.41 +/- 0.7, P < 0.05) (a compartment syndrome). The low basal pancreatic pH(I) (7.23 +/- 0.02) did not change with secretin stimulation, since bicarbonate secretion was minimal. DD decreased IP (3.66 +/- 0.5 versus 2.81 +/- 0.5, P < 0.05) and increased PMBF (50 +/- 6 versus 79 +/- 6, P < 0.05) and pH(I) (7.24 +/- 0.02 versus 7.34 +/- 0.02, P < 0.05). The normal increase in PMBF after stimulation was restored (79 +/- 6 versus 218 +/- 54, P < 0.05). pH(I) now increased with stimulation (7.34 +/- 0.002 versus 7.37 +/- 0.002, P < 0.05), perhaps due to the marked hyperaemic response.

CONCLUSIONS

DD acutely restored basal and stimulated PMBF and IP towards normal. Basal pancreatic pH(I) also improved and reflects the underlying ischaemia.

Ethanol-mediated neutrophil extravasation in feline pancreas

Ethanol is a common cause of both acute and chronic pancreatitis. Studies in other organs suggest that polymorphonuclear neutrophils activated by ethanol may cause tissue injury in a variety of conditions. The aim of this study was to investigate the effects of ethanol on neutrophil extravasation in the feline pancreas. Pancreata were isolated and perfused at different flow rates with varying concentrations of ethanol in either a physiological or neutrophil depleted perfusate. Neutrophil extravasation was assessed by measuring pancreatic tissue myeloperoxidase (MPO) activity. Ethanol at 2.5% (54.25 mmol/liter) was the lowest concentration that still caused significant neutrophil extravasation (3.1+/-0.8 vs 1.9+/-0.2 units, P<0.05) and was accompanied by an increase in vascular resistance of 15%. Reduction of pancreatic perfusion by 15% did not significantly increase neutrophil extravasation. (1.1+/-0.3 vs 1.6+/-0.2 units, NS) Perfusion of the pancreas with neutrophil-depleted blood containing either ethanol or saline, followed by perfusion with an ethanol-free perfusate, showed an increase in neutrophil extravasation in the ethanol group compared to the control group (3.2+/-0.9 vs 1.9+/-0.2 units, P<0.05). In conclusion, ethanol causes neutrophil extravasation in the feline pancreas independent of blood flow changes and occurs despite the absence of direct neutrophil exposure to ethanol.

[Ulcus cruris--vascular etiology and surgical treatment options]

Leg ulcers comprise a problem with various contributing factors requiring selective therapy adapted to the underlying cause. The majority can be classified as arterial (approx. 20%) or venous (approx. 80%) ulcers. Arterial ulcers as well as most mixed (arterial-venous) ulcers can be treated by arterial reconstruction and subsequent skin grafting, with additional ligation of perforator veins or (segmental) stripping of the saphenous vein. Leg ulcers due to chronic insufficiency of the deep venous system are most often the result of previous deep venous thrombosis followed by recanalization and development of a postthrombotic syndrome. Compression regimens remain standard therapy with emphasis on preventing ulcer formation. Ulcer healing can be achieved by compression therapy although recurrence rates are high. Surgery is not the treatment of first choice for leg ulcers, however, in selected cases surgical therapy is indicated. To prevent recurrence, continued consistent compression, keeping the patient well-informed and offering supportive guidance are imperative.

Port site metastases following laparoscopic cholecystectomy for unsuspected carcinoma of the gallbladder

Laparoscopic cholecystectomy is considered as the new gold standard operation for removal of the gallbladder, and has several advantages over the traditional open cholecystectomy. However, in the last few years there is an increasing number of case reports of port site metastases following laparoscopic cholecystectomy for unsuspected carcinoma of the gallbladder. Two case reports of trocar site metastases are presented, and they further highlight the concern of the role of minimal invasive surgery in the presence of unsuspected carcinoma of the gallbladder. In this review we speculate on the mechanisms which may be responsible for metastatic deposits during laparoscopic cholecystectomy and suggest certain recommendations.

[Abnormalities of the inferior vena cava and their significance in surgery of abdominal aortic aneurysms]

Anomalies of the inferior vena cava result from failures of regression during embryogenesis. Although occurring relatively infrequently, they can pose serious hazards to the surgeon during aortic aneurysm repair. Based on 2 recent cases, embryologic origins, incidence and clinical presentation of these anomalies are discussed. Different suggestions are proposed that might aid the surgeon in dealing with these anomalous structures during operations on the abdominal aorta.

Stenting does not decompress the pancreatic duct as effectively as surgery in experimental chronic pancreatitis

BACKGROUND

In humans with chronic pancreatitis (CP), pancreatic interstitial pressure (IP) is elevated and pancreatic blood flow (PBF) is reduced. The efficacy of surgical decompression (SD) of the pancreatic duct (ie, pancreaticojejunostomy) is believed to be due to its ability to decrease IP and pancreatic vascular resistance (Rp), which increases PBF. Pancreatic duct stenting (STE) also probably reduces IP and Rp, which may explain its efficacy. The purpose of this study was to compare the efficacy of SD with STE.

METHODS

CP in cats was created by narrowing the main pancreatic duct. Six weeks later, CP and normal pancreata were isolated and perfused ex vivo under basal conditions and after secretin stimulation. In normal and CP glands, IP and perfusion pressure were measured and Rp (U) was calculated. In two additional groups, the pancreatic duct was decompressed, either by stenting or by complete transection of the duct with a longitudinal capsulotomy.

RESULTS

In CP glands, IP and Rp were increased and secretory output was markedly reduced compared with the normal (0.65 +/- 0.30 mm Hg and 0.46 +/- 0.04 U vs 3.90 +/- 0.80 mm Hg and 1.68 +/- 0.05 U; P < .05). Secretin administration (2 units) increased IP and Rp in CP glands (6.60 +/- 1.10 mm Hg and 2.87 +/- 0.07 U; P < .05), but these values did not chang in normal glands (0.81 +/- 0.20 and 0.53 +/- 0.03 U; NS). STE and SD decreased IP and Rp in CP glands (2.20 +/- 0.20 to 1.0 +/- 0.40 mm Hg and 1.20 +/- 0.015 to 0.90 +/- 0.01 U, respectively; P < .05). Both methods prevented an increase of IP and Rp after secretin administration. IP and Rp decreased to a greater degree following SD, compared with STE (P < .05).

CONCLUSIONS

Both STE and SD decreased IP and Rp in this experimental model of CP. However, SD was significantly more effective than STE.

Intragastric alcohol causes endothelin release from feline pancreas

The mechanism by which alcohol causes pancreatic damage is still largely unknown. One important contributory factor may be the endothelins, potent vasoconstricting endothelial-derived peptides. The aim of this study was to examine in vivo endothelin release from the pancreatic vascular endothelium after alcohol ingestion. In anesthetized cats immunoreactive endothelin was measured in serum after instillation of alcohol into the stomach (20 ml, 40%). After intragastric alcohol, a rise in endothelin was seen in pancreatic venous effluent (to a mean of 24.5 +/- 7.7 pg/ml at 60 min). Control serum from the femoral artery exhibited no rise in endothelin (2.11 +/- 1.2 pg/ml). Pancreatic blood flow was significantly decreased in a further group to 93% basal after intravenous infusion of 0.1 nmol/kg ET-1 and to 61% after infusion of 1 nmol/kg ET-1. Portal serum levels of endothelin were 105 pg/ml and 15 pg/ml, respectively, immediately following bolus infusion and decreased to normal levels within 120 sec. We conclude that the serum endothelin rise after intragastric ethanol may be a major factor behind the drop in pancreatic blood flow.

Superselective microcoil embolization: treatment of choice in high-risk patients with extrahepatic pseudoaneurysms of the hepatic arteries

BACKGROUND

Only a few isolated case reports of extrahepatic pseudoaneurysms of the hepatic arteries have been published. We present the first documented series of patients with extrahepatic pseudoaneurysms treated at a single institution, and discuss the etiology and management of this condition.

STUDY DESIGN

A retrospective review of all cases of extrahepatic pseudoaneurysms of the hepatic arteries between 1989 and 1997.

RESULTS

A total of seven patients with extrahepatic pseudoaneurysms of the hepatic arteries all had upper abdominal pain; five patients were also in shock secondary to a gastrointestinal bleeding from ruptured pseudoaneurysms. The most common factor of the pseudoaneurysms was previous pancreatobiliary surgery in five patients with blunt truncal trauma and chronic pancreatitis in the remaining two patients. Initial endoscopy and ultrasonography were unrevealing, whereas dynamic computed tomography (CT) scan and angiography were diagnostic. The median size of the pseudoaneurysms was 3.6 cm (range 2.1-5.7). Treatment consisted of superselective transcatheter microcoil embolization in five hemodynamically unstable patients and surgical resection of the pseudoaneurysms with vascular reconstruction in the two stable patients. Mortality and morbidity were 0% and 43%, respectively. In a median followup of 35 months (range 2-96), no recurrence of pseudoaneurysm has been found.

CONCLUSIONS

A high index of suspicion combined with appropriate diagnostic modalities are required for the diagnosis of extrahepatic pseudoaneurysms. In high-risk patients, superselective transcatheter microcoil embolization should be considered the treatment of choice.

Missed diaphragmatic injuries and their long-term sequelae

BACKGROUND

Blunt or penetrating truncal traumas can result in diaphragmatic rupture or injury. Because diaphragmatic defects are difficult to diagnose, those that are missed may present with latent symptoms of obstruction of herniated viscera.

METHODS

A chart review of all patients admitted with late presentations of posttraumatic diaphragmatic hernias from 1980 to 1996 was undertaken.

RESULTS

Ten patients with posttraumatic diaphragmatic hernias were treated in this specified period. There were six males and four females with a mean age of 65 years. Eight patients sustained blunt truncal traumas and two patients sustained penetrating truncal traumas. The hernias occurred in two patients on the right and in eight patients on the left side and contained the liver (n = 2), bowel (n = 10), stomach (n = 4), omentum (n = 5), or spleen (n = 1). The time until the hernias became clinically symptomatic ranged from 20 days to 28 years. In all but one patient, either routine chest roentgenograms or upper gastrointestinal contrast studies were diagnostic. All 10 patients underwent laparotomy (n = 9) or thoracotomy (n = 2) with direct repair of the diaphragmatic defect. One patient died 3 days after the operation, representing a mortality of 10%; the morbidity was 30%.

CONCLUSION

Initial recognition and treatment of diaphragmatic rupture or injury is important in avoiding long-term sequelae.

Gout: rare cause of hallucal sesamoid pain: a case report

Tophaceous gout is commonly encountered and is amenable to effective medical management. A rare case of tophaceous gout in a tripartite medial sesamoid bone of the great toe is presented. Clinical presentation, differential diagnosis, and treatment of hallucal sesamoid pain are discussed.

[Pancreatic pseudocysts in chronic pancreatitis. Differential diagnosis and therapy]

Pancreatic pseudocysts occur as a complication in the natural course of acute or chronic pancreatitis, with a spontaneous resolution rate of 40% to 60%. The incidence of pseudocysts in the course of chronic pancreatitis amounts to 60%. Pseudocysts have to be differentiated from neoplastic or congenital pancreatic cystic lesions. Careful diagnostic work-up including ERCP and CT scanning is mandatory in the management of pancreatic pseudocysts. The indication for treatment depends on the development of symptoms or complications. Pain is present in up to 90% of all patients, and the rate of complications varies between 2% and 55%. Pancreatic pseudocysts are usually an epiphenomenon of chronic pancreatitis. Pancreatic resection therefore represents a causative treatment. New percutaneous and endoscopic techniques for draining pseudocysts are challenging the previous hegemony of the surgeon. However, so far no prospectively collected data are available comparing the results of interventional and surgical drainage procedures. Therefore, in most symptomatic cases surgery is considered the treatment of choice.

[Duodenum preserving resection of the head of the pancreas: a standard procedure in chronic pancreatitis]

Duodenum-preserving resection of the head of the pancreas was developed 25 years ago by Beger. This procedure is indicated in patients suffering from chronic pain in combination with inflammation of the head of the pancreas, common bile duct obstruction, pancreatic duct obstruction and/or obstruction of the retropancreatic vessels. At the Inselspital in Berne, 74 patients underwent this operation between 1993 and 1996. The median length of the operation was 380 min, with the need for transfusion in a median of 0 units (0-6). There was no postoperative mortality. Total postoperative morbidity was 13%. One patient needed relaparotomy on day 17 for small bowel obstruction. Median length of hospital stay was 11 days. Postoperatively, two patients developed diabetes. Duodenum-preserving resection of the head of the pancreas represents an organ-preserving principle of surgery. This procedure treats the complications of chronic pancreatitis and provides long-term pain relief in more than 80% of patients.

[Surgical therapy in chronic pancreatitis]

In patients with chronic pancreatitis, surgical treatment is required when conservative approaches are unsuccessful in treating symptoms and complications of the disease. The indications for surgery are 1) recurrent abdominal pain which does not respond to analgesics and 2) duodenal, common bile duct and/or main pancreatic duct obstruction or stenosis. In addition, obstruction of the retropancreatic vessels with subsequent portal hypertension is an indication to operate. Over the last decades the surgical standards in the treatment of chronic pancreatitis have changed. Due to disappointing long-term results, pancreatic left resection and drainage procedures of the main pancreatic duct are limited only to a small number of patients. In a number of patients with chronic pancreatitis, inflammatory enlargement of the pancreatic head causes complications which require surgical treatment. In the past, the classical Whipple resection has served as the standard operation in these patients. However, the classical Whipple resection was initially inaugurated for pancreatic head malignancies, and in addition to resection of the pancreatic head it includes resection of the complete duodenum, the extra hepatic bile system and 2/3 of the stomach. The Whipple procedure's disappointing long-term results and especially its disappointing quality of life have led to the development of newer organ-preserving procedures designed to treat complications caused by chronic pancreatitis. The pylorus-preserving Whipple resection is a modification of the classical Whipple resection which avoids the resection of the stomach. Since its initial publication by Watson in 1945 and Traverso and Longmire in 1978, pylorus preserving Whipple resection has been performed by many surgeons for the treatment of chronic pancreatitis. However, the high incidence of postoperative diabetes mellitus following this operation is a major drawback that has limited its use. The duodenum-preserving pancreatic head resection was developed to selectively remove the pancreatic head subtotally by preserving the body and tail of the pancreas as well as the pylorus, the duodenum, and the extrahepatic biliary tract. With this organ-preserving operation all the pancreatic head-related complications of chronic pancreatitis can be abolished without inducing diabetes mellitus. Excellent short- and long-term follow-up results prove the superiority of the duodenum-preserving pancreatic head resection over the classical and the pylorus-preserving Whipple resections in patients with chronic pancreatitis. Therefore, the duodenum-preserving pancreatic head resection should be adopted as a new standard operation in patients with chronic pancreatitis and pancreatic head-related complications.

Ischaemia-reperfusion mechanisms in acute pancreatitis

The role of ischaemia in the pathogenesis of acute pancreatitis is unknown. Some experimental studies have shown that ischaemia has little effect on the pancreas, while others have found an association with pancreatic injury. Ischaemia-reperfusion damage has been well documented in other sites such as the intestine, cardiac muscle, and skeletal muscle. However, in the pancreas, injury is usually seen only after complete ischaemia, which is uncommon clinically. Experimental chronic pancreatitis is characterized by low pancreatic blood flow, low interstitial pH, and impaired pancreatic tissue oxygenation, which are all findings consistent with the ischaemia-reperfusion mechanisms. Acute pancreatitis is also associated with a reduction in pancreatic blood flow and evidence of free radical generation, similarly suggesting the possibility of ischaemia-reperfusion injury. Ethanol ingestion, which is commonly associated clinically with both chronic and acute pancreatitis, may itself contribute to an ischaemic-reperfusion injury. We have shown that administration of ethanol to cats decreases pancreatic blood flow and may also directly activate neutrophils. Further investigation is needed to determine whether or not these findings are also associated with an ischaemia-reperfusion injury.

Pancreatic interstitial pH in human and feline chronic pancreatitis

BACKGROUND & AIMS

Advanced chronic pancreatitis is associated with a reduction in pancreatic blood flow. To determine the physiological significance of this decrease, pancreatic interstitial pH was measured in a model of obstructive chronic pancreatitis in cats and in patients with chronic pancreatitis.

METHODS

In cats, pancreatic interstitial pH and blood flow were measured serially under basal conditions and after secretory stimulation as chronic pancreatitis evolved. Basal pancreatic interstitial pH was also measured in patients undergoing an operation for chronic pancreatitis or periampullary cancer (controls).

RESULTS

In normal cats, pancreatic interstitial pH was 7.41 +/- 0.01 and blood flow was 124 mL.min-1.(100 g pancreas-1). With the evolution of chronic pancreatitis, interstitial pH and blood flow progressively decreased to 7.21 +/- 0.04 (P < 0.007) and 75 +/- 11 (P < 0.007), respectively. From 1 to 2 weeks, secretory stimulation reduced pancreatic interstitial pH and blood flow further, but as secretory function was lost, this effect disappeared. In patients with chronic pancreatitis, the interstitial pH was lower (7.02 +/- 0.06) than in controls (7.25 +/- 0.04; P < 0.05).

CONCLUSIONS

These observations are consistent with the hypothesis that, in chronic pancreatitis, acidic metabolites associated with pancreatic secretion accumulate within the pancreas, probably because of impaired blood flow.