Biomedical subjects

J M Müller

Publications and source records attributed to J M Müller.

At least 145 records · Page 8Linked to original sources

PubMed1997

Intermittent sequential compression of the lower limbs prevents venous stasis in laparoscopic and conventional colorectal surgery.

PURPOSE: This study was designed to evaluate the influence of intraoperative intermittent sequential compression (ISC) on venous blood return from the lower limbs during laparoscopic and conventional colorectal colectomy. METHODS: Fifty patients undergoing laparoscopic (n = 25) or conventional (n = 25) colorectal surgery were included in a prospective study. Peak venous flow (PFV) and the cross-sectional area (CSA) of the femoral vein were assessed by Doppler ultrasound examination intraoperatively. RESULTS: Age, gender, and body mass index were comparable between both groups. Baseline PFV was 21 +/- 6.6 cm/s in the conventional and 18.4 +/- 6.4 cm/s in the laparoscopic group (P = 0.2). ISC increased PFV to 156 +/- 29 percent of the baseline value in the conventional group and to 161 +/- 29 percent in the laparoscopic group. PFV decreased after abdominal insufflation to 127 +/- 19 percent of the baseline value in the laparoscopic group and after laparotomy to 134 +/- 27 percent in the conventional group (P = 0.3). PFV decreased slightly in both groups during surgery but remained well above the baseline value. Baseline CSA was 1.02 +/- 0.17 cm2 in the conventional group and 1 +/- 0.23 cm2 in the laparoscopic group. ISC decreased CSA to 0.91 +/- 0.18 cm2 (conventional) and 0.85 +/- 0.18 cm2 (laparoscopic) after initiation of ISC. CSA was 0.92 +/- 0.18 cm2 after abdominal insufflation in the laparoscopic group, and it was 0.93 +/- 0.18 cm2 after laparotomy in the conventional group (P = 0.4). During surgery, there were no differences in absolute CSA or CSA changes compared with the baseline value in both groups. Postoperative circumference of the calf and thigh were not different between both groups. Postoperative thromboembolic complications did not occur. CONCLUSION: ISC effectively increases venous blood flow from the lower limbs during conventional and laparoscopic colorectal resections and may decrease the risk of postoperative deep vein thrombosis. Therefore, ISC is strongly recommended in every prolonged laparoscopic procedure.

Aged↗

PubMed1997

[Peritoneal instillation of taurolidine and heparin for preventing intraperitoneal tumor growth and trocar metastases in laparoscopic operations in the rat model].

BACKGROUND: Although port-site metastases occur after laparoscopic surgery, there is no generally accepted approach to prevent tumor implantation so far. METHODS: In order to prevent tumor metastases, the effect of taurolidine and heparin on the growth of colon adenocarcinoma DHD/K12/TRb was measured in vitro and in a rat model. After incubation of the cells with heparin, taurolidine or both substances, the cell kinetics were determined. In a second experiment, tumor cells were administered intraperitoneally in rats (n = 60) and pneumoperitoneum was established over 30 min. Rats were randomized into four groups (I: tumor cells; II: cells + heparin; III: cells + taurolidine; IV: cells + taurolidine + heparin). RESULTS: While tumor cell growth was not influenced by heparin in vitro, growth decreased significantly after incubation with taurolidine and taurolidine/heparin. In vivo, intraperitoneal tumor weight was lower in rats receiving heparin (298 +/- 155 mg) and taurolidine (149 +/- 247 mg) than in the control group (596 +/- 278 mg). When the two substance were combined, tumor growth was even less (21.5 +/- 36 mg). Trocar metastases were only lower in rats receiving taurolidine or the combination of taurolidine and heparin. CONCLUSION: In vivo, heparin inhibits intraperitoneal tumor growth only slightly, while taurolidine causes a significant decrease in tumor cell growth in vitro as well as intraperitoneal tumor growth and trocar metastases in vivo.

Adenocarcinoma↗

PubMed1997

[Comparison of local and systemic inflammation after laparotomy or laparoscopy in the rat sepsis model].

BACKGROUND: Laparoscopic techniques are frequently used in patients with peritonitis or intra-abdominal inflammatory diseases although increased intraperitoneal pressure may cause sepsis by promoting bacteraemia and systemic inflammatory response. METHODS: This experimental study investigates the influence of laparotomy and laparoscopy on bacteraemia, tumour necrosis factor (TNF)-alpha and endotoxin plasma levels. Standardized foecal inoculum was injected intraperitoneally and rats underwent either laparotomy (n = 20), laparoscopy (n = 20), or no further manipulation in the control group (n = 20). RESULTS: One hour after intervention, bacteraemia was significantly higher in both the laparotomy or laparoscopy groups than in the control group (P = 0.01). Foecal inoculum caused a significant increase in TNF-alpha and endotoxin plasma levels 1 h after intervention with the significantly highest levels after laparotomy (P < 0.05). In addition, the mean number of intraperitoneal abscesses were also significantly higher (P < 0.05) after laparatomy (n = 10) than after laparoscopy (n = 8) or in the control group (n = 5). CONCLUSIONS: Laparotomy and laparoscopy increased the incidence of bacteraemia and systemic inflammation compared to control group. However, inflammatory response and intraperitoneal abscess formation were significantly higher in the laparotomy group than in the laparoscopy group.

Abdominal Abscess↗

PubMed1997

[Value of laparoscopic technique in primary colorectal carcinoma].

Patients who had undergone elective resection for primary colorectal cancer were included in a prospective study. The purpose of the study was to specify the current role of laparoscopic surgery in the treatment of colorectal cancer. Therefore, the reasons for performing the resection conventionally were documented under the general guideline that all colorectal cancer should be resected laparoscopically. Of 111 patients treated in 1995, only 22 underwent a laparoscopic resection and 4 patients a laparoscopic-assisted resection. Age, sex and tumor stage were comparable between groups. Operative time was longer in the laparoscopy group; duration of postoperative ileus and postoperative hospital stay were shorter. The most frequent indications for using a conventional approach were rectal cancer (n = 29), adhesions (n = 15), randomly selected patients (n = 14) and advanced cancer (n = 12). Cardiovascular risk factors were not so important. Laparoscopic techniques were only applied in a minority of patients with colorectal cancer (24-37%). Laparoscopic sphincter-preserving surgery is currently not recommended for rectal cancer in the middle and lower rectum. General risk factors are rarely a contraindication for a laparoscopic approach.

Aged↗

PubMed1997

[Perioperative nutritional therapy and its relevance for postoperative outcome].

The clinical effect of perioperative nutrition was analyzed from 28 controlled clinical trials. Preoperative nutritional support is indicated only in patients with high-grade malnutrition and can reduce the postoperative morbidity and mortality in these patients. If the nutritional status is normal preoperatively, artificial nutrition may influence the postoperative outcome negatively. A clinical benefit from postoperative nutritional support has been proven only in patients not able to eat an adequate oral diet within 1 week. In 20% of these case a cardiopulmonary complication was observed during total parenteral nutrition. The infusion of D5W is sufficient in the majority of surgical patients even after major procedures.

Enteral Nutrition↗

PubMed1997

Does laparoscopy increase bacteremia and endotoxemia in a peritonitis model?

BACKGROUND: Laparoscopy is increasingly used in patients with intraabdominal bacterial infection although pneumoperitoneum may increase bacteremia by elevated intraabdominal pressure. METHODS: The influence of laparotomy and laparoscopy on bacteremia, endotoxemia, and postoperative abscess formation was investigated in a rat model. Rats received intraperitoneally a standardized fecal inoculum and underwent laparotomy (n = 20), or laparoscopy (n = 20), or no further manipulation in the control group (n = 20). RESULTS: Bacteremia and endotoxemia were higher after laparotomy and laparoscopy compared to the control group (p = 0.01) 1 h after intervention. One hour after intervention, aerobic and anaerobic bacterial species were detected in the laparotomy group while only anaerobic bacteria were found in the other two groups. Although bacteremia and endotoxemia did not differ among the three groups after 1 week, the mean number of intraperitoneal abscesses was significantly higher (p < 0.05) after laparotomy (n = 10) compared with laparoscopy (n = 6) and control group (n = 5). CONCLUSION: Laparoscopy does not increase bacteremia and intraperitoneal abscess formation compared to laparotomy in an animal model of peritonitis.

Abscess↗

PubMed1997

The influence of laparotomy and laparoscopy on tumor growth in a rat model.

BACKGROUND: The effects of laparotomy and laparoscopy with different gases on subcutaneous and intraperitoneal tumor growth have not been evaluated yet. METHODS: Tumor growth of colon adenocarcinoma DHD/K12/TRb was measured in rats after laparotomy, laparoscopy with CO2 or air, and in control group. Cell kinetics were determined after incubation with carbon dioxide or air in vitro and tumor growth was measured subcutaneously and intraperitoneally after surgery in vivo. RESULTS: In vitro, tumor cell growth increased significantly after incubation with air and CO2. In vivo, intraperitoneal tumor weight was increased after laparotomy (1,203 +/- 780 mg) and after laparoscopy with air (1,085 +/- 891 mg) and with CO2 (718 +/- 690 mg) compared to control group (521 +/- 221 mg) (p < 0.05). Subcutaneous tumor growth was promoted after laparotomy (71 +/- 35 mg) and even more after laparoscopy with air (82 +/- 45 mg) and CO2 (99 +/- 55 mg) compared to control group (36 +/- 33 mg). CONCLUSIONS: Insufflation of air and CO2 promote tumor growth in vitro. In vivo, intraperitoneal tumor growth seems to be promoted primarily by intraperitoneal air and subcutaneous tumor growth by CO2.

Adenocarcinoma↗

PubMed1997

Inhibition of peritoneal tumor cell growth and implantation in laparoscopic surgery in a rat model.

BACKGROUND: The pathogenesis of portsite recurrences after laparoscopic surgery is still unknown, and a generally accepted approach to prevent tumor implantation does not exist. METHODS: The effect of taurolidine and heparin on growth of colon adenocarcinoma DHD/K12/TRb was measured in vitro and in vivo. After incubation of the cells with heparin or taurolidine or both substances, cell kinetics were determined. In a rat model (n = 60), tumor cells were administered intraperitoneally, and pneumoperitoneum was established over 30 minutes. Rats received tumor cells, tumor cells + heparin, tumor cells + taurolidine, or tumor cells + taurolidine + heparin. RESULTS: In vitro, tumor cell growth decreased after incubation with taurolidine and taurolidine/heparin. In vivo, intraperitoneal tumor weight was lower in rats receiving heparin (298 +/- 155 mg) and taurolidine (149 +/- 247 mg) compared with the control group (596 +/- 278 mg) but even less when both substances were combined (21.5 +/- 36 mg). CONCLUSION: Heparin inhibits intraperitoneal tumor growth in vivo slightly, while taurolidine causes significant decrease of tumor cell growth in vitro as well as tumor take and intraperitoneal tumor growth in vivo.

Adenocarcinoma↗

PubMed1997

Pneumoperitoneum with carbon dioxide stimulates growth of malignant colonic cells.

BACKGROUND: Port-site recurrences have often been reported after laparoscopic surgery for malignant disease, and the pathogenesis is unknown. Whether different gases used to establish pneumoperitoneum have an influence on tumor cell growth has not been investigated. METHODS: Tumor growth of colon adenocarcinoma DHD/K12/TRb was measured in a rat model after insufflation with either carbon dioxide or helium and in a control group. Tumor growth was evaluated in three experiments: (1) in vitro (n = 60), (2) ex vivo (n = 60), and (3) in vivo (n = 60). After insufflation, cell kinetics were determined in the first two experiments. In the third experiment, tumor growth was measured subcutaneously and intraperitoneally 5 weeks after insufflation. RESULTS: Tumor cell growth increased significantly after insufflation with carbon dioxide in vitro (p < 0.03) and ex vivo (p < 0.05) compared with the control group, whereas helium did not stimulate cell growth. In vivo, subcutaneous tumor growth was promoted by carbon dioxide (131 +/- 55 mg) (p < 0.01) compared with helium (35 +/- 34 mg) and the control group (36 +/- 33 mg). Total intraperitoneal tumor weight was 717 +/- 320 mg in carbon dioxide group compared with helium (549 +/- 231 mg) and control group (570 +/- 321 mg). CONCLUSIONS: The insufflation of carbon dioxide promotes tumor growth compared with helium and control in a rat model. Further studies should confirm these results before alternative gases should be recommended in laparoscopic surgery for malignant diseases.

Adenocarcinoma↗

PubMed1997

Does pneumoperitoneum with different gases, body positions, and intraperitoneal pressures influence renal and hepatic blood flow?

BACKGROUND: Because of the well-known negative effects of carbon dioxide pneumoperitoneum on the hemodynamic and respiratory system, it was questionable how pneumoperitoneum may affect hepatic and renal blood flow. Therefore the influences of different gases, different intraperitoneal pressures, and different body positions on hepatic and renal blood flow were investigated in a porcine model. METHODS: Cardiac and hemodynamic function were monitored by means of implanted catheters in the pulmonary artery and the femoral vein and artery. Renal and hepatic blood flow were recorded with a transonic volume flow meter placed at the renal and hepatic arteries and the portal vein. Eighteen animals were randomly assigned to receive one of three insufflation gases (carbon dioxide [CO2], argon, or helium. After baseline recording, one of three intraperitoneal pressures (8, 12, or 16 mm Hg) and one of three body positions (supine head up, or head down) were randomly chosen. After an adaptation time of 15 minutes, all data were recorded for 15 minutes. This was repeated until all nine combinations had been investigated. The end points of the study were blood flow in the hepatic and renal arteries and the portal vein, cardial output, systemic vascular resistance, and central venous pressure. RESULTS: Total liver blood flow was reduced on relation to intraabdominal pressure, head-up position, and argon insufflation. Arterial hepatic blood flow was reduced by the head-up position and argon insufflation. Portal venous blood flow decreased with the pig in the head-up position, with increased intraabdominal pressure, and argon insufflation. Renal blood flow was reduced by the head-up position and increased pressure. There was no correlation (p < 0.6) between systemic hemodynamic parameters (cardiac output, central venous pressure, and systemic vascular resistance) and hepatic and renal blood flow. CONCLUSIONS: Head-up position and intraperitoneal pressure greater than 12 mm Hg should be avoided during laparoscopic surgery because they compromise hepatic and renal blood flow. Argon insufflation impairs liver blood flow. However, helium may be advantageous compared with CO2 insufflation.

Animals↗

PubMed1997

Surgical therapy of esophageal carcinoma: the influence of surgical approach and esophageal resection on cardiopulmonary function.

OBJECTIVE: The effects of the different surgical approaches (transhiatal esophagectomy and right-sided transthoracic esophagectomy) on perioperative cardiopulmonary function in the surgical treatment of esophageal carcinoma are discussed controversially and have not yet been evaluated. METHODS: In a prospective randomized study including 32 patients, we investigated the effects of the surgical approach (blunt dissection (n = 16) versus transthoracic en-bloc resection (EB) (n = 16)) in the treatment of esophagus carcinoma on perioperative cardiopulmonary function. The following parameters were measured in all patients: cardiac index (CI), mean arterial pressure (MAP), central venous pressure (CVP), mean pulmonary artery pressure (MPAP), pulmonary capillary wedge pressure (PCWP), intrapulmonary shunt (QS/QT), arterio-alveolar (aaDO2), arterio-venous oxygen pressure difference (avDO2), and blood gas analyses. Time of measurement were: after induction of anesthesia, beginning and end of esophagus resection, end of surgery, 1 h postoperatively, and then every 12 h until the third postoperative day. RESULTS: Compared to blunt dissection, en-bloc esophagectomy was found to be associated with a transient deterioration of pulmonary function during one-lung ventilation in the left-lateral position, which could already be compensated for during the intervention. No other significant differences in cardiopulmonary effects were seen between the two surgical techniques. The incidence of postoperative complications was identical in both groups. CONCLUSIONS: The results of our study show that en-bloc resection is only associated with an increased intraoperative pulmonary strain that is completely compensated during the operation and that there is no difference in cardiopulmonary functions between the two techniques in the postoperative course.

Adenocarcinoma↗

PubMed1997

[The plug and patch repair for managing the inguinal hernia of the adult].

The basic principles of the Plug and Patch Repair of inguinal hernia are positioning of a prolene plug behind the internal ring in combination with a prolene onlay patch on the fascia transversalis. From July 1994 until December 1996 243 inguinal hernias were operated in this technique in a consecutive series of 221 patients. There were 211 primary and 32 recurrent hernias. 187 operations were performed in local anesthesia and 34 patients wished general anesthesia. No intraoperative complications were noted. The average operation time was 36 +/- 14 minutes. Postoperative complications were 8 subcutaneous hematomas and 1 superficial wound infection, which healed spontaneously. The average stay in hospital was 2 +/- 2 days and the patients returned to work after 17 +/- 11 days. Patients' self assessment of postoperative pain and limitations of daily activities revealed an excellent comfort. The follow-up rate is 97% and no late complications were observed after a median follow-up time of 21 months. The Plug and Patch technique is a very promising procedure for inguinal hernia repair in adults.

Activities of Daily Living↗

PubMed1997

[Progress in laparoscopic sigmoid resection in elective surgical therapy of sigmoid diverticulitis].

The full significance of laparoscopic technique in elective surgery of sigmoid diverticulitis has yet to be determined. However, it seems worthwhile to evaluate how minimally invasive surgery could be integrated into the surgical treatment of diverticulitis disease. Between January 1995 and August 1996, 26 patients with sigmoid diverticulitis underwent elective surgery. Following diagnostic laparoscopy, seven patients were treated with primary conventional resection, 15 patients with laparoscopic resection and four patients with laparoscopic-assisted surgery. One laparoscopic resection had to be converted to a median laparotomy. Postoperative complications (n = 2) only appeared in the group of conventional resections. Conventional resections required less time than laparoscopic or laparoscopic-assisted resections, but postoperatively, patients with laparoscopic resection were able to defecate sooner and required a shorter hospital stay. For 60% of the patients with diverticulitis disease of the colon, elective laparoscopic resection may prove to be the best alternative of surgical treatment. In selected patients it is a sound technique with a low complication rate. We recommend that all patients with diverticulitis disease requiring elective surgery undergo diagnostic laparoscopy to determine whether or not laparoscopic resection is a viable option.

Aged↗

PubMed1997

TEM--minimal invasive therapy of rectal cancer?

The aim of this study is to outline the use of transanal endoscopic microsurgery (TEM) for local excision of rectal carcinoma. Thus the clinical and long-term results regarding endorectal excision of the rectal lesions at the University Hospital of Cologne and Berlin will be presented. During the period July 1983 till December 1993 the system has been employed on 405 cases (17.8% carcinomas) at the University Hospital of Cologne and on 60 cases (20% carcinomas) during the period September 1994 till September 1996 at the University Hospital of Berlin, Charité. Early postoperative complications consisted of intraperitoneal perforations (five cases); rectovaginal fistulas (four cases); haemorrhages (four cases), death due to cardiopulmonary failure (two cases). All the complications occurred within the first 4 years of the learning phase. The cancer-specific 3-year survival rate of patients with "low risk" pT1 cancers amounted to 91%. Two recurrences after local excision of pT1 cancers occurred 1 year postoperatively, which were treated successfully using the TEM system. Most of the histologic findings of the subsequent radical operations following local resections of infiltrative rectal cancers revealed that the carcinoma had already been totally removed. The main indication for TEM is the removal of sessile adenomas. Early rectal carcinomas (pT1) of the "low risk" type, with favourable histological grading (grade 1 and 2) and clinical staging (CS I) were also considered for endorectal therapeutical approach. Even though our initial results do show encouraging results, regarding endorectal excision of pT2 cancers, more experience is needed to clarify the indication for locally amenable pT2 cancers of the "low risk" type and rule out the role of adjuvant therapy after complete excision of these carcinomas. The indication for TEM encloses also confined (< 4 cm) infiltrative cancers (> pT1) in cases where the patient is unwilling to undergo extensive surgery or due to medical reasons. The technique allows accurate endoscopic microsurgical excision of early cancers for cure with minimal morbidity and excellent presentation of specimen for complete histological analysis. Diligent follow-up is mandatory, since most (60-80%) of local recurrences can be treated successfully. Thus demolitive surgery can be avoided in selected cases with rectal cancer.

Adenoma↗

PubMed1997

[Introduction of video endoscopic vascular surgery of the pelvic area].

The fact that operative lethality and other typical postoperative complications following surgical treatment of aortoiliac atherosclerotic disease are mainly related to the surgical trauma (derived from the extensive abdominal incision and dissection), but not to the classical arterial reconstruction itself, has led us to develop a videoendoscopic aortoiliacal surgical method which is supposed to diminish the potential postoperative complications. Thus, a new endoscopic instrument set for vascular surgery has been developed in close cooperation with Aesculap AG Tuttlingen, Germany. After evaluating the basic techniques of videoendoscopic patching and end-to-side anastomosis with the newly designed instruments on a training model (n = 50), the feasibility of videoendoscopic vascular surgery on aortoiliacal vessels was tried out on human corpses (n = 8). The positive results of the initial survey have finally encouraged us to conduct our first series of animal studies on piglets (n = 25). The investigation regarding ultrasonically monitored blood flow in the femoral arteries after videoendoscopic aortofemoral bypass grafting and other systemic, hemodynamic parameters showed positive results. No complications were encountered in any of the standardized animal studies. Favorable activity levels were recorded. Meanwhile we have performed 5 extraperitoneal videoendoscopic aortofemoral artery bypasses in patients with aortoiliac occlusive diseases. One patient in whom we had occluded the inferior mesenteric artery died due to an ischaemic colitis. The other patients had an uneventful postoperative course. The videoendoscopic vascular procedures were carried out according to the rules of conventional vascular surgery. Nevertheless, further experimental research and development of endoscopic instruments have yet to be done, to optimize the new surgical method and to clarify the advantages of videoendoscopic vascular surgery.

Animals↗

PubMed1997

[Perspectives of minimal invasive surgery].

The rapid and often uncritical introduction of complex minimal invasive procedures in clinical routine has been increasingly criticized. Even established minimal invasive techniques as for instance laparoscopic cholecystectomy are discussed controversial. Causes hereof are the lack of basic research and the unstructured development of new operative techniques. The possibilities of physiology adjusted basic research in minimal invasive surgery and stepwise a structured testing of new operative techniques are demonstrated. The changing conditions of the next century demand critical evaluation of the effectiveness of video-endoscopic surgery in prospective randomized trials, if it will keep or expand its present clinical importance.

Forecasting↗

PubMed1997

[Minimal invasive surgery in clinically occult breast carcinoma].

The ABBI (Advanced Breast Biopsy Instrumentation) system is a new method of breast surgery of nonpalpable tumors which permits intraoperative mammography. In a pilot study it was shown that a small carcinoma can be removed by a mammographically and stereotactically controlled biopsy (20 mm maximum diameter). An indicated breast-conserving therapy can be carried out when using this method.

Biopsy↗

PubMed1996

Quality of life following resection of oesophageal carcinoma.

Quality of life following resection of oesophageal carcinoma was assessed by patients using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire and by a psychologist using the Spitzer Index. Quality of life was evaluated in 119 patients on one occasion 12 months after operation and in 30 patients regularly, starting with a preoperative assessment. Self and external evaluation showed a significant correlation (r = 0.61), but quality of life was assessed as being higher by the external observer. Limited physical performance status and somatic complaints were the most important postoperative dysfunctions, whereas emotional, social and economic disorders were found to be less frequent and less severe. Of several factors analysed only tumour recurrence (P < 0.01) and anastomotic stricture (P < 0.05) lowered quality of life significantly. Compared with the preoperative assessment, quality of life had decreased on discharge from hospital but was restored within 6 months of operation in disease-free patients. Further studies are required to determine the impact of adjuvant therapy for quality of life in patients undergoing surgery for oesophageal cancer.

Activities of Daily Living↗