Peritoneal transforming growth factor beta-1 expression during laparoscopic surgery: a clinical trial

BACKGROUND

Transforming growth factor-beta 1 (TGF-beta1) is a growth factor involved in various biologic processes, including peritoneal wound healing and dissemination of malignancies. Laparoscopic surgery is evolving rapidly, and indications are increasing. The peritoneal TGF-beta1 expression during laparoscopic surgery is unknown.

METHODS

For this study, 50 patients scheduled for laparoscopic cholecystectomy were randomized into five groups, then surgically treated with various pressures, light intensities, and dissection devices. Peritoneal biopsies were taken at the beginning and end of surgery. Tissue concentrations of total and active TGF-beta1 were measured using enzyme-linked immunosorbent assay (ELISA) techniques.

RESULTS

There was no significant difference in either total or active TGF-beta1 concentration between peritoneal biopsies taken at the start of surgery and samples taken at the end of the procedure. Patients who underwent surgery with the ultrasonic scalpel had significant lower levels of both active (p < 0.005) and total (p < 0.01) TGF-beta1 at the end of surgery than patients treated with electrocautery. Patients who had surgery with a high light intensity had significantly lower levels of total TGF-beta1 levels (p < 0.005) with an unchanged active part than patients who had surgery with low light intensity.

CONCLUSION

The choice of dissection device and the light intensity used in laparoscopic surgery affect peritoneal TGF-beta1 concentrations, indicating that peritoneal biology can be affected by laparoscopic surgery. Because TGF-beta1 is involved in various biologic processes in the peritoneal cavity, this observation may have important clinical consequences.

Treatment of a ruptured thoracoabdominal aneurysm with a stent-graft covering the celiac axis

PURPOSE

To present a case of successful emergency endovascular repair of a ruptured, probably mycotic, thoracoabdominal aortic aneurysm (TAAA) with a stent-graft deliberately covering the celiac axis.

CASE REPORT

A 79-year-old woman with significant pulmonary comorbidity presented with a ruptured mycotic TAAA extending to the celiac axis. The aneurysm was excluded with a stent-graft soaked in rifampicin and deployed to deliberately occlude the celiac axis for effective distal sealing and fixation. The patient recovered well and was prescribed antibiotic treatment for up to 6 months.

CONCLUSION

Endovascular repair of a ruptured TAAA may be a life-saving option. In emergency situations when poor distal anatomy is present, covering the celiac artery with the stent-graft should be considered.

Varicose vein surgery and endovenous laser therapy

Varicose veins are a widespread problem, and are encountered by various medical specialists. Symptoms can appear from mild, such as tiredness of the legs, to severe chronic ulcers. Varicose veins are generally caused by the reflux of an incompetent saphenofemoral junction and long saphenous vein. In the presence of reflux, the treatment should be directed at the ablation of the hydrostatic forces of the reflux. Conventional surgical treatment consists of a high ligation of the saphenofemoral junction and stripping of the saphenous vein. In the era of minimally invasive surgery, various endovenous techniques have been developed, including endovenous laser therapy. This technique is relatively cheap and can be performed under only local anesthesia. During endovenous laser therapy, energy is delivered to the vein wall, causing it to shrink and eventually occlude. Currently, the mechanisms of action involved in laser treatment are not fully understood. Clinical studies have shown occlusion rates to be very competitive to conventional high ligation and stripping and superior cosmetics. Complications may include mild to moderate pain, ecchymosis, induration, hematoma, and phlebitis. All of these are generally self-limiting. In the challenge of finding the correct balance between a low incidence of varicose vein recurrence and complications and optimal cosmetic results, endovenous laser therapy is a promising modality. However, controlled studies that assess the effectiveness of endovenous laser therapy in comparison to saphenofemoral ligation with saphenous vein stripping are crucial before considering endovenous laser therapy as the new standard treatment.

Hyaluronan-based antiadhesive agents in abdominal surgery: applications, results, and mechanisms of action

Postsurgical intra-abdominal adhesions cause significant morbidity and mortality, with small bowel obstruction being the most common complication. The urge to prevent adhesion formation has resulted in multiple experimental and clinical trials and the development of numerous antiadhesive agents. Through the years, hyaluronan-based antiadhesives have proved to be successful in the reduction of adhesion formation. Despite the obvious effectiveness of hyaluronan, there is still much debate on its clinical use and mechanisms of action. Various hyaluronan-containing products have been introduced and withdrawn from the market. The application of hyaluronan in combination with meshes for hernia repair appears to be a promising concept. Not all different applications of hyaluronan are well known and its use in patients with a malignancy or abdominal infection remains controversial. Here an overview is given on the effects of hyaluronan-based antiadhesive agents in abdominal surgery, its use in infectious conditions, and its oncologic repercussions. The most important mechanism of action appears to be the mechanical separation of damaged peritoneal surfaces. However, the biological effects of hyaluronan, such as modulation of cell proliferation and peritoneal biology, might also be of influence.

Influence of monocyte-like cells on the fibrinolytic activity of peritoneal mesothelial cells and the effect of sodium hyaluronate

OBJECTIVE

To determine whether the presence of cells of the monocyte-macrophage system affects the fibrinolytic response of peritoneal mesothelial cells to lipopolysaccharide (LPS) in the presence and absence of sodium hyaluronate.

DESIGN

Controlled laboratory experiment.

SETTING

Cell cultures in an academic laboratory research environment.

PATIENT(S)

Human peritoneal mesothelial cells were harvested from patients undergoing a laparotomy for noninfectious reasons and were cultured in vitro. Co-cultures were formed by adding U-937 human monocyte-like cells to a monolayer of mesothelial cells.

INTERVENTION(S)

After 24 hours, cultures were treated with 10 ng/mL of LPS, and sodium hyaluronate was added in a final concentration of 0.2%. Controls received medium without sodium hyaluronate.

MAIN OUTCOME MEASURE(S)

After 24 hours' incubation, tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor-1 (PAI-1) levels were determined in medium and cell lysates by using ELISA techniques.

RESULT(S)

In medium of co-cultures, tPA and PAI-1 concentrations were statistically significantly increased compared with the case of monocultures, whereas uPA concentration was statistically significantly decreased. In cell lysates of co-cultures, PAI-1 concentration was statistically significantly increased compared with the case of monocultures, whereas tPA and uPA were unaffected. Treatment with sodium hyaluronate statistically significantly decreased PAI-1 and uPA concentrations in medium of monocultures but decreased uPA concentration only in medium of co-cultures, compared with the case of controls.

CONCLUSION(S)

Cells of the monocyte-macrophage system modulate the fibrinolytic capacity of LPS treated human peritoneal mesothelial cells and interfere in the hyaluronan-associated changes in mesothelial fibrinolytic capacity.

Expanding use of nonpenetrating clips in various surgical specialities

The Anastoclip Vessel Closure System (VCS) (LeMaitre Vascular, Burlington, MA, USA), introduced primarily to facilitate microvascular anastomoses performed during neurosurgical extra-intracranial bypasses, has been used for several other applications as well. The relatively new anastomotic technique includes a clip applier, clip remover, and everting forceps. With the applier, tiny nonpenetrating titanium clips were installed on everted walls of tubular structures. The technical ease of application, reduced anastomotic time, superior hemodynamics, and an improved healing pattern at the anastomosis have been recognized as major advantages compared to conventional suturing. This chapter describes the various indications for use of the system and categorizes them by specific surgical specialties, which include neurosurgery, urology, and gynecology, as well as plastic and reconstructive, vascular, thoracic, transplantation, hepatopancreaticobiliary, and orthopedic and trauma surgery. The largest clinical experience with clips is in vascular access surgery for hemodialysis purposes, both in autologous constructs and with prosthetic grafts. Promising clinical results also have been achieved in neurosurgical cases (both for microvascular anastomoses and with closure of dura mater), microvascular free-tissue transfer, and renal and liver transplantations. Future clinical applications include the use of clips for nerve repair and closure of various types of tubular structures using a laparoscopic approach.

Future of operating rooms

Operating-room design has not changed significantly since the modern era of surgery began. Minimal invasive, endoscopic, procedures, and evolution of technology will affect operating-room design in the near future. Poor ergonomics has always been one of the major drawbacks of endoscopic surgery. Use of retractable arms and monitors will improve ergonomics of the operating team. Developments in telecommunication will allow surgeons to communicate with colleagues and experts during the procedure in virtually any location around the world, which increases teaching possibilities and procedural safety. Introduction and further development of intraoperative imaging, including real-time, three-dimensional (3-D) reconstructions of patient, and computer-aided surgery offer surgeons the opportunity to train the planned surgical procedure. Moreover, they will improve control and supervision of the procedure in learning situations. The last decade's robotics have made their introduction into the operating rooms. They improve control over the operating-room environment and will facilitate the performance of more complex procedures. However, high costs and lack of force feedback remain its major drawbacks. Improvements of robotic techniques and its implementation into the operating rooms will further guide their design into highly specialized operating units.

Hyaluronan-Based Antiadhesive Membrane Has No Major Effect on Intraperitoneal Growth of Colonic Tumour Cells

BACKGROUND

A relationship between post-surgical adhesion formation and peritoneal tumour implantation has been proposed. Hyaluronan (HA)-based agents reduce adhesion formation, but the effect on peritoneal tumour is not established. This study investigated the influence of a HA-containing agent on intraperitoneal tumour in an experimental model.

METHODS

66 Balb/c mice underwent laparotomy and damage was inflicted to the parietal peritoneum. The animals were randomized into five groups. Groups 1 and 2 received HA-carboxymethylcellulose bioresorbable membrane and no treatment, respectively. Mice in groups 3-5 were injected intraperitoneally with 10(5) colon 26-B cells after the laparotomy. Treatment consisted of HA membrane, no HA agent and placement of HA membrane on the non-traumatized peritoneal wall, respectively. Animals were killed after 14 days; adhesions were scored in groups 1 and 2, and the tumour mass in groups 3-5. 45 Wag/Rij rats underwent the same procedures and treatment as mice in groups 3-5. In rats, 10(6) CC-531 cells were injected. Rats were killed after 3 weeks and the tumour mass was scored.

RESULTS

HA membrane resulted in a significant reduction of adhesions, but had no major effect on the intraperitoneal tumour mass in mice and rats.

CONCLUSION

HA-carboxymethylcellulose bioresorbable membrane has no major effect on intraperitoneal tumour implantation and growth in an experimental model.

Cardiac arrhythmias after laparoscopic banding

Morbid obesity is associated with various disorders and may effectively be treated by restrictive surgery, such as laparoscopic adjustable gastric banding (LAGB). We observed a patient suffering from cardiac arrhythmias following LAGB. These cardiac events were likely evoked by hypokalemia due to persistent vomiting after placement of the band. We describe a case of continuing vomiting following a gastric banding procedure. Causes may include both mechanical, i.e. gastric prolapse, and psychological factors. The present case stresses the need for frequent follow-up for patients after a gastric restrictive operation.

Pathophysiology of intra-abdominal adhesion and abscess formation, and the effect of hyaluronan

BACKGROUND

Intra-abdominal adhesions and abscesses cause significant morbidity and mortality. The formation of fibrin in the abdominal cavity is a common pathophysiological pathway for both. The aim of this review was to investigate the pathophysiology of intra-abdominal adhesions and abscesses, and to explore the possible sites of action of hyaluronan.

METHODS

Data were reviewed from the literature using the Medline database.

RESULTS

Both surgery and peritonitis disturb the equilibrium between coagulation and fibrinolysis in the abdominal cavity in favour of the coagulation system. Hyaluronan-based agents reduce adhesion formation after surgery. Moreover, hyaluronan solution reduces abscess formation in experimental peritonitis. Possible mechanisms of action include mechanical separation of wound surfaces, improvement of peritoneal healing, modulation of the inflammatory response and enhanced fibrinolysis.

CONCLUSION

Diminished fibrin degradation is a common pathway for the formation of adhesions and abscesses. The potential of hyaluronan-based agents to reduce intra-abdominal adhesions and abscesses in abdominal surgery and sepsis is a promising new concept. Elucidating the mechanisms involved and the clinical application of hyaluronan in peritonitis are challenges for future research.

Rebound phenomenon in tissue plasminogen activator activity of parietal peritoneum after anastomosing colon in rats with bacterial peritonitis

Background

This study aimed to measure the fibrinolytic response, which plays a role in adhesion and abscess formation, of the parietal peritoneum to surgery in the presence and absence of bacterial peritonitis.

Methods

In 48 male Wistar rats bacterial peritonitis was induced using caecal ligation and puncture (CLP). Some 24 h after CLP (day 0), 12 rats were killed and biopsies were taken from the parietal peritoneum. The remaining 36 rats were reoperated whereby the ligated caecum was resected followed by resection of a 1-cm segment of the descending colon and end-to-end anastomosis. Thirty additional rats underwent resection of a 1-cm segment and anastomosis of the descending colon without any previous procedure. One-third of the rats were killed on days 1, 3 and 7 after anastomosing the colon, and biopsies were taken from the parietal peritoneum. From ten untreated rats, biopsies were taken for measurement of baseline levels. All biopsies were homogenized and tissue plasminogen activator (tPA) activity was measured using an enzyme-linked immunosorbent assay.

Results

Some 24 h after inducing peritonitis (day 0), tPA activity was significantly (P &lt; 0·0001) decreased compared with baseline levels. One day after anastomosis in rats with peritonitis, tPA activity was in the same range as baseline values, while tPA activity was significantly increased on days 3 and 7 after anastomosis, in comparison to baseline levels (P = 0·0002). There was no significant difference in tPA activity compared with baseline levels 1, 3 and 7 days after anastomosing colon in normal rats.

Conclusion

In rats with bacterial peritonitis, tPA activity in the parietal peritoneum was depressed after 24 h; 24–48 h after inducing peritonitis, tPA activity increased, reaching supranormal levels at days 3–7. Surgery alone does not influence tPA activity of the parietal peritoneum.

Time course of peritoneal tissue plasminogen activator after experimental colonic surgery: effect of hyaluronan-based antiadhesive agents and bacterial peritonitis

BACKGROUND

This study assessed the peritoneal fibrinolytic response during the first week after colonic surgery in rats with and without bacterial peritonitis, and possible modulation of the response by two hyaluronan-based antiadhesive agents.

METHODS

A colonic anastomosis was constructed in 90 male Wistar rats. Peritonitis was induced in another 108 rats and a colonic anastomosis was constructed after 24 h. Rats in both groups were randomized into an untreated group or one of two groups treated with hyaluronan-based agents. One-third of each group was killed at each of days 1, 3 and 7 after operation, and tissue plasminogen activator (tPA) antigen and activity were measured in peritoneal biopsies.

RESULTS

One day after colonic surgery in normal rats, tPA antigen concentration was significantly (P < 0.005) increased, whereas tPA activity levels were normal. By day 3 after operation tPA antigen had returned to baseline values while tPA activity was significantly increased (P < 0.05). One day after inducing peritonitis tPA antigen was significantly increased (P < 0.001), while tPA activity was significantly reduced (P < 0.05). Three and seven days after colonic surgery in rats with peritonitis tPA activity was increased (P < 0.001) while tPA antigen had returned to baseline values. Neither of the hyaluronan-based agents affected peritoneal tPA antigen levels or activity after colonic surgery.

CONCLUSION

Both abdominal surgery and infection caused an early increase in peritoneal tPA antigen levels, followed by an increase in tPA activity. Peritonitis severely depressed early tPA activity. Application of hyaluronan-based agents did not affect the peritoneal fibrinolytic response to surgery and/or infection.