Biomedical subjects

J Heisterkamp

Publications and source records attributed to J Heisterkamp.

13 recordsLinked to original sources

PubMed2005

Totally extraperitoneal repair for bilateral inguinal hernia: does mesh configuration matter?

BACKGROUND: The endoscopic preperitoneal approach has numerous advantages for the reconstruction of bilateral inguinal hernias. Repair may be achieved using either one large or two small meshes. The aim of this study was to investigate whether one of the techniques was superior in terms of recurrence and complication rate. METHODS: Data obtained from 113 patients who underwent surgery between January 1998 and December 2001 was reviewed. For the sake of this study, 86% of all patients were examined for hernia recurrence at an additional outpatient visit. RESULTS: The findings showed recurrence rates, of 3.5% for single mesh and 3.7% for double mesh. This difference was not significant. Complication rates did not differ significantly between the groups. CONCLUSIONS: Endoscopic preperitoneal bilateral hernia repair is a safe and reliable technique in the hands of experienced surgeons. The rate of hernia recurrence and complications is low and independent of the mesh configuration (single or double). Mesh configuration based on personal preference is permissible.

Adult↗

PubMed2005

Long-term follow-up after umbilical hernia repair: are there risk factors for recurrence after simple and mesh repair.

Adult umbilical hernia is a common surgical condition mainly encountered in the fifth and sixth decade of life. Despite the high frequency of the umbilical hernia repair procedure, disappointingly high recurrence rates, up to 54% for simple suture repair, are reported. Since both mesh and suture techniques are used in our clinic we set out to investigate the respective recurrence rates and associated complications, retrospectively. Patients who were treated between January 1998 and December 2002 were identified from our hospital database and invited to attend the outpatient department for an extra follow-up, history taking and physical examination. The use of prosthetic material, occurrence of surgical site infection, body mass and height as well as recurrence were recorded at the time of this survey. In total, 131 consecutive patients underwent operative repair of an umbilical hernia. Twenty-eight percent of the patients were female (n = 37). In 12 patients (11%) umbilical hernia repair was achieved with mesh implantation. Fourteen umbilical hernia recurrences were noted (13%); none had been repaired using mesh. No relationship was found between wound infection or obesity and umbilical hernia recurrence. In the light of these results it is necessary to re-evaluate our clinical "guidelines" on mesh placement in umbilical hernia repair: apparently not every umbilical fascial defect needs mesh repair. Research should focus on establishing risk factors for hernia recurrence.

Adult↗

PubMed2004

Long-term results after modified Gallie technique for incisional hernia repair: results in 19 patients.

BACKGROUND: A modified forgotten technique for repairing large incisional hernias is described together with its long-term results in 19 patients. A synthetic mesh with 1-cm wide spokes radiating from the mesh is placed preperitioneally, overlapping the fascial defect. The spokes are pulled through rectus sheaths and muscle and sutured ventrally, thereby creating a solid reconstruction withstanding shrinking of the mesh. METHOD: Nineteen patients were operated on (13 primary incisional hernia, minimal fascial defect 10 cm). Notes on patients were reviewed, and the patients were contacted for follow-up examination. RESULTS: No major complications occurred. After a median of 49 months, 17 patients were reviewed at the outpatient clinic. Two possible recurrences were detected, of which one was operated on. This proved to be bulging of the mesh, resulting in a recurrence of 1 out of 17 (6%). CONCLUSION: From these results, it is concluded that Gallie's technique using synthetic mesh is a safe and effective repair for incisional hernia and deserves more attention, especially for large fascial defects.

Aged↗

PubMed2003

Interstitial laser coagulation with temporary hepatic artery occlusion for patients with cirrhosis and irresectable hepatoma.

BACKGROUND: The aim was to determine the degree of local control of hepatocellular carcinoma (HCC) in patients with cirrhotic liver disease when treated with ultrasonographically guided interstitial laser coagulation (ILC) with temporary hepatic artery occlusion. METHODS: Sixteen patients with 24 HCC tumours were treated. Follow-up was by computed tomography or magnetic resonance imaging every 3 months. RESULTS: Nineteen of 24 tumours showed complete necrosis immediately after treatment, and there was no tumour recurrence during follow-up (mean 14 months, median 12 months). No effect on liver function was observed after 1 week and there was no death. In 13 of the 16 patients, new HCC foci developed at other sites. CONCLUSION: Percutaneous ILC combined with temporary hepatic artery occlusion during a single session is an effective local treatment for HCC nodules smaller than 5 cm. However, new HCC lesions develop in the majority of patients, which underscores the need for adjuvant therapy or repeated treatment in these patients.

Aged↗

PubMed2001

Metabolic activity and DNA integrity in human hepatic metastases after interstitial laser coagulation (ILC).

BACKGROUND AND OBJECTIVE: For investigations into interstitial laser coagulation (ILC) of solid tumors, tissue whitening is used as a parameter for the extent of coagulation. This obvious demarcation is associated with global thermal denaturation, but it is not clear whether this finding is a good indicator of the exact outer boundary of the lethal tissue effect. STUDY DESIGN/MATERIALS AND METHODS: ILC with portal inflow occlusion was performed in human hepatic metastases of colorectal carcinoma directly after surgical resection (n = 5) or before surgical resection (n = 5) with laser parameters adapted to tumor diameter. Mitochondrial NADH-diaphorase activity and DNA integrity were assessed by histoenzymatic staining. RESULTS: In 7 of 10 tumors (mean diameter, 3.7 cm), an area of macroscopic coagulation (mean diameter, 4.2 cm) encircled the tumor in all three axes. Macroscopic coagulation corresponded to absent metabolism and disintegrated DNA. Furthermore, the macroscopic volumes of coagulation produced in tumor were comparable to the dimensions in normal porcine liver with the same laser parameters. CONCLUSION: ILC with portal inflow occlusion results in areas with complete cell avitality in the zone of tissue whitening in human hepatic liver metastases.

Colorectal Neoplasms↗

PubMed2000

[Treatment of non-resectable liver tumors with percutaneous interstitial laser coagulation while interrupting blood circulation to the liver].

OBJECTIVE: To evaluate, in patients with hepatocellular carcinoma or colorectal carcinoma disseminated to the liver, treatment with interstitial laser coagulation (ILC) during temporary occlusion of vascular inflow in the liver: feasibility, complications and initial tumour response. DESIGN: Prospective, descriptive. METHODS: Patients were included if their tumours were surgically irresectable and smaller than 4 cm in diameter and did not exceed a number of 3. ILC was performed under general anaesthesia, basically via a percutaneous approach. Vascular inflow was occluded during laser treatment. Twenty-four hours after ILC a triphasic spiral CT was performed to assess the result of the treatment. RESULTS: In 10 patients 14 hepatic tumours were lasered in 12 treatment sessions (10 percutaneous and 2 at laparotomy). After 5 treatment sessions, complications were observed of which pain at the insertion site of the catheters was the most frequent. For 6 out of the 10 patients with percutaneous procedures, discharge was within 24 hours after ILC. Nine out of the 14 tumours (65%) were completely coagulated. CONCLUSION: ILC with vascular inflow occlusion is a safe and feasible technique that can be performed during a short hospital stay. Initial tumour response is 65% and these results justify determination of duration of response in a larger group of patients.

Aged↗

PubMed1999

Critical temperature and heating time for coagulation damage: implications for interstitial laser coagulation (ILC) of tumors.

BACKGROUND: Interstitial laser coagulation (ILC) is a method of local tissue destruction for solid tumors such as irresectable hepatic metastases from colorectal cancer. With the availability of new magnetic resonance (MR) techniques, which allow real time tissue temperature mapping, it is essential to know the critical temperature and exposure times leading to cell death. MATERIALS AND METHODS/STUDY DESIGN: Samples (8 mm(3)) of solid rat tumor (CC-531, syngenic to the WAG/Rij rat strain), were warmed in tubes for four different temperatures (40, 50, 60 or 80 degrees C) and four different exposure times (3, 6, 12, or 24 minutes). Combinations were replicated in five-fold. Cell viability was assessed with three methods: Trypan blue exclusion test in collagenase/dispase dissociated samples, NADH activity in snap frozen samples and outgrowth for 2 weeks under the renal capsule of WAG/Rij rats. RESULTS: Results of the three methods revealed that viability was not affected with heating at 40 and 50 degrees C except for 24 minutes at 50 degrees C. At higher temperatures cell death occurred at all exposure times. CONCLUSION: The temperature range resulting in sufficient tissue coagulation for cell death is between 50 degrees C and 60 degrees C for a short duration (<3 minutes). These data can be used to achieve complete tumor destruction and minimal surrounding tissue damage during real-time MR-controlled ILC.

Animals↗

PubMed1999

Accuracy of MR phase mapping for temperature monitoring during interstitial laser coagulation (ILC) in the liver at rest and simulated respiration.

The chemical shift or proton-resonance frequency (phase mapping) can be used to measure temperature changes. As a subtraction technique, it requires scans at exactly the same location, making it prone to respiration-induced artifacts. The accuracy of magnetic resonance (MR) phase mapping for temperature monitoring of interstitial laser coagulation (ILC) was therefore investigated in two ex vivo models with simulated respiration. MR temperatures were calibrated to interstitially measured temperature. Gradual cooling of a homogenous medium (gel) was monitored for four starting temperatures (room temperature, 40 degrees C, 50 degrees C, and 60 degrees C) during 30 min. Temperature increases were measured during ILC in ex vivo porcine liver with Nd:YAG for 6 min with 5 Watt. Experiments were performed at rest and with simulated respiratory motion (both n = 5). In liver, accuracy did not decrease with respiration simulation (P = 0.32), whereas a significant decline was found in the gel model (P = 0.002). In all experiments a small drift over time was observed between temperature determined with MR and thermoprobes. Correction for temperature-independent phase-shift at a reference location did not enhance agreement. Temperatures could be determined correctly by MR in the moving liver within a range of +/-3.5 degrees C after 6 min of laser application (95% confidence interval), justifying further pre-clinical studies.

Analysis of Variance↗

PubMed1999

Long-term effects of interstitial laser coagulation in porcine liver with portal inflow occlusion: central versus peripheral lesions.

PURPOSE: Interstitial laser coagulation (ILC) is an attractive modality for local destruction of unresectable hepatic metastases. Portal inflow occlusion considerably increases its destructive capacity, resulting in lesions 5 cm in diameter; however, effects on adjoining major intrahepatic structures are unknown. Therefore, the purpose of this study was to assess the effects of ILC with portal inflow occlusion on the central portion of the liver as compared to the peripheral portions. MATERIALS AND METHODS: ILC was performed in pigs with portal inflow occlusion. Each animal received a single laser application with Nd:YAG light guided simultaneously through four interstitial fibers with 5 W per fiber during 6 minutes. Location of treatment was randomized to either central (n = 8) or peripheral (n = 8). Follow-up was for 1, 2, or 3 months with evaluation of liver functions and weight, as well as macroscopic and microscopic assessment of coagulated lesions and surrounding parenchyma. RESULTS: There was no treatment-related morbidity or mortality. No obstructive cholestasis or bile leakage was found. At every moment of evaluation, coagulated volumes in the central group were smaller than in the peripheral lesions (P = .03). Large vessels contiguous to the lesions in the central group were always intact and indications of portal hypertension or thrombosis of hepatic veins were not found. There were no significant differences between the two groups (liver functions [P > or = .15] and weight [P = .69]). CONCLUSION: ILC with portal inflow occlusion is a safe technique in the vicinity of vital structures in the liver of healthy pigs. These results justify studies to the feasibility and complication rate of portal inflow occlusion in patients with hepatic malignancies.

Animals↗

PubMed1999

Interstitial laser coagulation for hepatic tumours.

BACKGROUND: The potential role of interstitial laser coagulation (ILC) for patients with irresectable hepatic tumours is currently being investigated. Since its introduction in 1983 it has evolved into an innovative minimally invasive technique. METHODS: On the basis of a Medline literature search and the authors' experience, the principles, current state and prospects of ILC for hepatic tumours are reviewed. RESULTS: Animal studies and early clinical studies have shown the safety and feasibility of ILC. The site of interest can be approached at laparoscopy or percutaneously and treatment is easily repeatable. Recent advances include the use of fibres with a cylindrical diffusing light-emitting tip, the length of which is adaptable to tumour diameter, water-cooled fibre systems, simultaneous multiple fibre application, and hepatic inflow occlusion during laser treatment. ILC allows complete destruction of tumours up to 5 cm in diameter. Currently a limitation is the lack of reliable real-time monitoring of laser-induced effects but progress in magnetic resonance imaging techniques should allow accurate temperature measurements to be obtained rapidly during treatment. However, the actual benefit of ILC in terms of patient survival remains to be investigated. CONCLUSION: In terms of tools and experience, ILC has now been developed sufficiently to study its effect on survival of patients with irresectable hepatic tumours.

Humans↗

PubMed1997

Heat-resistant cylindrical diffuser for interstitial laser coagulation: comparison with the bare-tip fiber in a porcine liver model.

BACKGROUND AND OBJECTIVE: Interstitial laser coagulation is an experimental treatment to eliminate solid tumors such as hepatic metastases. The pattern of light emission from the fiber tip is probably an important factor in determining the size and shape of a lesion. A heat-resistant cylindrical light diffusing tip of 2 cm length was developed for this application. We performed an in vitro study to compare this diffusing-tip with a bare-tip fiber. STUDY DESIGN/MATERIALS AND METHODS: Fiber ends were positioned between two porcine liver slabs (37 degrees C) and Nd:YAG laser light (1064 nm) was guided through either fiber with an output of 3-9 W and exposure times of 6-18 minutes. RESULTS: Lesions produced by the cylindrical diffuser tip were significantly larger and more predictable. With the diffuser tip, lesions up to 36/23 mm (length/width) could be produced at 7 W and 9 min without any central charring. The maximum size of lesions produced with the bare-tip fiber was 32/20 mm at 6 W for 9 min with massive charring. CONCLUSIONS: The results indicate that at optimal laser settings, the diffuser tip produces a larger coagulation volume than a bare-tip fiber. For clinical application, cylindrical diffusing fibers should be used with a diffusing length adapted to the diameter of the tumor.

Animals↗

PubMed1997

Importance of eliminating portal flow to produce large intrahepatic lesions with interstitial laser coagulation.

BACKGROUND: Interstitial laser coagulation is a local treatment modality for solid tumours, such as liver metastases. Perfusion by the vascular system can transfer heat from the treatment site, thereby reducing the volume of destroyed tissue. METHODS: This effect was investigated in a pig model (n = 10). Lesions were produced in the liver with four interstitial laser fibres (5 W per fibre for 6 min): (1) with flow through the liver (n = 9); (2) with the portal vein clamped (n = 8); and (3) with both hepatic artery and portal vein clamped (n = 6). The pigs were killed and the liver was dissected; lesions were assessed macroscopically and microscopically. RESULTS: The volume of the lesion was significantly larger when portal flow was eliminated (30.6 versus 6.4 cm3, P < 0.001). CONCLUSION: Hepatic blood flow substantially reduces the size of the lesion produced by laser coagulation. Portal flow should therefore be occluded during laser treatment to produce lesions of clinically relevant dimensions.

Animals↗

PubMedDate not supplied

P53 overexpression in colorectal metastases confined to the liver and outcome of liver resection.

BACKGROUND/AIMS: The results of hepatic surgery for colorectal metastases are distorted by the high incidence of recurrence, despite an apparently radical resection. Selection of high-risk patients is a mandatory step towards effective application of neo-adjuvant chemotherapy. In this study, expression of the tumor suppresser gene p53 in colorectal liver metastases was correlated with recurrence after resection. METHODOLOGY: In a retrospective case-series p53 expression was assessed using standard immunohistochemical methods in the paraffin-embedded specimens of 45 liver resections for colorectal metastases, performed in 43 patients in a single institution between '86 and '96. Hospital and office charts were reviewed and follow-up was completed with a General Physicians' questionnaire in October '97. Relapse-free and cancer-specific survival from diagnosis of hepatic metastases were assessed and compared for p53+ and p53- groups. RESULTS: Median survival was 36 months with an estimated 5-year cancer-specific survival of 43% (95% confidence interval 35%-51%). Relapse-free and cancer-specific survival were not significantly different between p53+ (n = 24, 53%) and p53- (n = 21) groups (P = 0.86 and P = 0.91 respectively). P53 expression was not associated with other potential predictors, which were not of predictive value either. CONCLUSIONS: Patients at risk for recurrent disease following partial hepatectomy for colorectal metastases cannot be identified by p53 expression.

Adenocarcinoma↗