Abstract
Introduction
Incisional hernias are a common complication following abdominal surgery and they represent about 80% of all ventral hernia. In uncomplicated postoperative follow-up they can develop in about eleven percent of cases and up to 23% of cases with wound infections or other forms of wound complications. Localisation and size of the incisional hernia can vary according to the causal abdominal scar. Conservative treatment (e. g. weight reduction) is only available to relieve symptoms while operative treatments are the only therapeutic treatment option for incisional hernia. Traditionally, open suture repair was used for incisional hernia repair but was associated with recurrence rates as high as 46%. To strengthen the abdominal wall and prevent the development of recurrences the additional implantation of an alloplastic mesh is nowadays commonly used. Conventional hernia surgery as well as minimally invasive surgery, introduced in the early 90s, make use of this mesh-technique and thereby showed marked reductions in recurrence rates. However, there are possible side effects associated with mesh-implantation. Therefore recommendations remain uncertain on which technique to apply for incisional hernia repair and which technique might, under specific circumstances, be associated with advantages over others.
Objectives
The goal of this HTA-Report is to compare laparoscopic incisional hernia repair (LIHR) and conventional incisional hernia repair with and without mesh-implantation in terms of their medical efficacy and safety, their cost-effectiveness as well as their ethical, social und legal implications. In addition, this report aims to compare different techniques of mesh-implantation and mesh-fixation as well as to identify factors, in which certain techniques might be associated with advantages over
others.
Methods
Relevant publications were identified by means of a structured search of databases accessed through the German Institute of Medical Documentation and Information (DIMDI) as well as by a manual search. The former included the following electronic resources:
SOMED (SM78), Cochrane Library – Central (CCTR93), MEDLINE Alert (ME0A), MEDLINE (ME95), CATFILEplus (CATLINE) (CA66), ETHMED (ED93), GeroLit (GE79), HECLINET (HN69), AMED (CB85), CAB Abstracts (CV72), GLOBAL Health (AZ72), IPA (IA70), Elsevier BIOBASE (EB94), BIOSIS Previews (BA93), EMBASE (EM95), EMBASE Alert (EA08), SciSearch (IS90), Cochrane Library – CDSR (CDSR93), NHS-CRD-DARE (CDAR94), NHS-CRD-HTA (INAHTA) as well as NHSEED (NHSEED).
The present report includes German and English literature published until 31.08.2005. The search parameters can be found in the appendix. No limits were placed on the target population. The methodological quality of the included clinical studies was assessed using the criteria recommended by the “Scottish Intercollegiate Guidelines Network Grading Review Group“. Economic studies were evaluated by the criteria of the German Scientific Working Group Technology Assessment for Health Care.
Results
The literature search identified 17 relevant medical publications. One of these studies compared laparoscopic and conventional surgery with and without mesh for incisional hernia repair, while 16 studies compared laparoscopic and conventional surgery with mesh for incisional hernia repair. Among these studies were 14 primary studies (one randomised controlled trial (RCT), two systematic reviews and one HTA-Report. The only study comparing laparoscopic and conventional surgery without mesh found substantial differences in terms of baseline characteristics between treatment groups. The outcome parameters showed decreased recurrence rates for the laparoscopic repair and similar safety of the procedures. Studies comparing laparoscopic and conventional surgery with mesh found similar outcome in terms of medical efficacy and safety. However, there was a trend towards lower recurrence rates, length of hospital stay, and postoperative pain as well as decreased complication rates for laparoscopic repair in the majority of studies. The impact of the technique of mesh-implantation and -fixation as well as the impact of certain factors on the choice of technique has not been systematically assessed in any of the studies.
Discussion
All identified studies suffer from significant methodological weaknesses, such as differences between treatment groups, mainly due to the non-randomised study design, small treatment groups causing low case numbers and lack of statistical power as well as the neglect of important risk factors or adjustment for those. Therefore, no conclusive differences could be identified concerning compared operative techniques, mesh-implantation and -fixation techniques or certain risk factors. Only the comparison of laparoscopic and conventional technique with mesh provides some evidence for a trend towards similar or slightly improved outcome in terms of medical efficacy and safety for the laparoscopic technique. However, there is still a great need for further research to investigate these questions.
Basically, there is no full economic evaluation focussing on the relevant alternatives. Cost compareisons were available, even though only briefly attached to clinical research results. None of the studies primarily aimed to investigate costs or even cost-effectiveness.
Conclusion
When deciding on the choice of operative technique for incisional hernia repair, surgeons take various considerations into account, including patient characteristics, hernia characteristics and their own experience. The studies included in this HTA did not provide conclusive evidence to answer the research questions. Nonetheless, laparoscopic surgery demonstrated a trend towards similar or slightly improved outcome following incisional hernia repair. However, for more conclusive recommendations on the choice of operative technique, high quality trials are required
From the economic perspective, alternative methods are not yet assessed. Only five of the studies involve a cost analysis, though in an insufficient manner. None of the studies identified were laid out as a health economic evaluation. Hence, further research is strongly recommended.
Abstract
Einleitung
Narbenhernien sind eine häufige Komplikation viszeralchirurgischer Eingriffe und stellen etwa 80% aller Ventralhernien dar. Bei normalem Heilungsverlauf im Anschluss an abdominelle Eingriffe treten sie bei etwa 11% der operierten Patienten auf. Im Anschluss an Wundheilungsstörungen finden sie sich sogar bei bis zu 23% der Fälle. In Abhängigkeit von der vorhergehenden Bauchwandnarbe können Narbenhernien der unterschiedlichsten Lokalisation und Größe auftreten. Von rein symptomatischen Behandlungsmöglichkeiten (Gewichtsreduktion, Bruchband) abgesehen, stellt die operative Versorgung von Narbenhernien in der Regel die einzige therapeutische Option dar. Traditionell kamen hierbei die offenen Nahtverfahren zum Einsatz, die jedoch mit erheblichen Rezidivraten von bis zu 46% verbunden sein können. Überwiegend erfolgt heutzutage die zusätzliche Implantation eines künstlichen Netzes, um die Bauchwand zu stärken und die Rezidiventstehung zu vermeiden. Sowohl konventionelle Techniken als auch minimalinvasive Verfahren, seit den frühen 90er Jahren angewendet, machen sich diese Technik zu Nutze und zeigten deutlich reduzierte Rezidivraten nach Behandlung von Narbenhernien. Aufgrund möglicher Komplikationen der Netz-Implantation bleibt jedoch weiterhin unklar, welche der drei zur Verfügung stehenden Techniken, gegebenenfalls unter bestimmten Bedingungen, als Standard der Versorgung von Narbenhernien empfohlen werden sollte.
Fragestellung
Ziel des „Health-Technology-Assessment“-Berichts (HTA)-Berichts ist es, die neuere laparoskopische Technik mit den konventionellen Operationsverfahren mit und ohne Netzeinlage zu vergleichen. Zielparameter sind die medizinische und ökonomische Effektivität, die Sicherheit der Verfahren sowie ethische, soziale und juristische Aspekte. Zudem sollen verschiedene Techniken der Mesh-Implantation bzw. -Fixation verglichen und spezifische Faktoren untersucht werden, ob die einzelnen Operationsverfahren Vorteile mit sich bringen könnten.
Methodik
Relevante Publikationen werden über eine strukturierte Datenbankrecherche durch das Deutsche Institut für Medizinische Dokumentation und Information (DIMDI) sowie mittels Handrecherche identifiziert. Die strukturierte Datenbankrecherche wird in folgenden Datenbanken durchgeführt:
SOMED (SM78), Cochrane Library – Central (CCTR93), MEDLINE Alert (ME0A), MEDLINE (ME95), CATFILEplus (CATLINE) (CA66), ETHMED (ED93), GeroLit (GE79), HECLINET (HN69), AMED (CB85), CAB Abstracts (CV72), GLOBAL Health (AZ72), IPA (IA70), Elsevier BIOBASE (EB94), BIOSIS Previews (BA93), EMBASE (EM95), EMBASE Alert (EA08), SciSearch (IS90), Cochrane Library – CDSR (CDSR93), NHS-CRD-DARE (CDAR94), NHS-CRD-HTA (INAHTA) sowie NHS-EED (NHSEED).
Die Literaturrecherche erstreckt sich bis 31. August 2005. Es erfolgt keine Einschränkung der Zielpopulation. Die Bewertung der methodischen Qualität erfolgt für den medizinischen Teil teils unter Berücksichtigung der Kriterien der „Scottish Intercollegiate Guidelines Network Grading Review Group“. Die Dokumentation der methodischen Qualität der ökonomischen Studien erfolgt unter Berücksichtigung der Checklisten zur Beurteilung der methodischen Qualität gesundheitsökonomischer Verfahren und der „German Scientific Working Group Technology Assessment for Health Care“.
Ergebnisse
Es wurden 17 medizinische Studien identifiziert. Davon verglich nur eine die Laparoskopie mit der konventionellen Operationstechnik mit und ohne Netzeinlage. 16 weitere Studien verglichen Laparoskopie und konventionelle Technik mit Netzeinlage. Es handelte sich dabei um 14 Primärstudien (eine randomisierte kontrollierte Studie (RCT)), zwei systematische Reviews und einen HTA-Bericht. Die einzige Studie zum Vergleich Laparoskopie vs. konventionelle Technik ohne Netzeinlage fand erhebliche Unterschiede zwischen beiden Behandlungsgruppen bezüglich wichtiger Risikofaktoren. Weiterhin zeigten sich verminderte Rezidivraten der laparoskopischen Technik bei ähnlicher Sicherheit. Der Vergleich von laparoskopischer und konventioneller Technik mit Netzeinlage zeigte ein sehr heterogenes Bild bei ähnlichen Ergebnissen für Effektivität und Sicherheit. Tendenziell fanden sich etwas niedrigere Rezidivraten, kürzere Krankenhausaufenthalte und geringere postoperative Schmerzen sowie etwas niedrigere Komplikationsraten in den laparoskopischen Behandlungsgruppen. Der Einfluss der Mesh-Implantation und der -Fixationstechnik sowie die Auswirkung wichtiger Einflussfaktoren wurden in keiner Studie systematisch untersucht.
Es können keine relevanten ökonomischen Studien identifiziert werden. Aus diesem Grund wurden nochmals eine Handsuche durchgeführt und die ökonomischen Volltexte erneut untersucht. Hier werden weniger strenge Anforderungen an die ökonomische Evaluationstechnik gestellt. Das Ausschlusskriterium „Studien mit einer geringen oder keiner ökonomischen Evidenz“ wird aufgeweicht und alle Studien berücksichtigt, die Kostenaspekte thematisieren. Es konnten fünf Studien identifiziert werden, von denen vier auch im medizinischen Teil herangezogen wurden.
Diskussion
Alle identifizierten medizinischen Studien weisen erhebliche methodische Mängel auf. Darunter fallen deutliche Gruppenunterschiede aufgrund des mehrheitlich nicht-randomisierten Studiendesigns, geringe Patientenzahlen (Fallzahl-, Powerprobleme) sowie die Vernachlässigung weiterer Einflussfaktoren im Rahmen der Auswertung. Aus diesen Gründen ergeben sich keine eindeutigen Ergebnisse bezüglich möglicher Unterschiede der verglichenen Operationsverfahren, der Netzimplantation und -fixation sowie einzelner untersuchter Faktoren. Lediglich der Vergleich Laparoskopie vs. konventionelle Technik mit Netzeinlage lässt bezüglich Sicherheit und Effektivität auf vergleichbare Ergebnisse beider Verfahren bzw. tendenziell leichte Vorteile der laparoskopischen Technik schließen.
Die Untersuchung der aufgeworfenen Forschungsfragen bringt vor dem Hintergrund der identifizierten Studien vor allem die Erkenntnis, dass gesundheitsökonomische Studien zu laparoskopischer Narbenhernioplastik im Vergleich zur konventionellen Operation mit oder ohne Netzeinlage faktisch nicht vorhanden sind. Die identifizierten Untersuchungen sind als Kostenvergleichsstudien einzustufen und lassen so keine Schlüsse auf Kosteneffektivitätsaspekte oder gesundheitspolitische Implikationen zu. Weiterer Forschungsbedarf ergibt sich deshalb für Kosteneffektivitätsuntersuchungen besonders für ein dem deutschen Gesundheitssystem entsprechendes Setting.
Schlussfolgerung
Der Operateur trifft die Entscheidung über die Wahl des Operationsverfahrens unter medizinischen Gesichtspunkten. Die Wahl des Verfahrens hängt von individuellen Patientenfaktoren, Herniencharaktersistika und der Erfahrenheit des Operateurs ab. Im Hinblick auf die Forschungsfragen ergeben sich aus den ausgewählten Studien keine eindeutigen Ergebnisse. Im Vergleich zur konventionellen Methode demonstriert die Laparoskopie jedoch vergleichbare bzw. tendenziell überlegene Ergebnisse im Rahmen der Behandlung von Narbenhernien. Die Durchführung qualitativ hochwertiger Studien ist allerdings erforderlich, um eindeutige Aussagen bezüglich der zu empfehlenden Operationsverfahren treffen zu können.
Aus ökonomischer Perspektive sind die alternativen Methoden praktisch nicht zu bewerten. Zwar werden fünf Studien gefunden, die Kostenaspekte in die Betrachtung mit einbezogen haben, jedoch ist deren Qualität nicht geeignet, um valide Schlüsse auf die Kostensituation oder Kosteneffektivitätsaspekte zuzulassen. Keine der betrachteten Untersuchungen ist als gesundheitsökonomische Evaluation angelegt, deswegen besteht weiterer Forschungsbedarf hinsichtlich Kosteneffektivitätsuntersuchungen besonders für ein dem deutschen Gesundheitssystem entsprechendes Setting.
Executive Summary
1. Health policy background
Health policy aims to secure and restore people’s health. To maintain the health care system at high standards as it has been is a current challenge as well as a future concern. In this context cost aspects have become increasingly important. Therefore the laparoscopic and conventional method to repair incisional hernias is investigated not only considering clinical aspects but economic aspects as well. To evaluate the status quo on this technology, a systematic research overview was conducted. Studies are evaluated with regard to clinical and economic evidence applying the latest tools for both, medical and economic dimensions. 200,000 hernias were diagnosed in Germany in 2003. Amongst those, ventral hernias are the second most common diagnosed hernias following inguinal hernias. Due to that vast number the political and economic relevance is apparent. The economic implications play an important role for the unit cost and society as a whole.
2. Scientific background
Incisional hernias are a common complication following abdominal surgery and they represent about 80% of all ventral hernia. In uncomplicated postoperative follow-up they can develop in about eleven percent of cases and up to 23% of cases with wound infections or other forms of wound complications.
Localisation and size of the incisional hernia can vary according to the causal abdominal scar. Conservative treatment (e. g. weight reduction) is only available to relieve symptoms while operative treatments are the only therapeutic treatment option for incisional hernia. Traditionally, open suture repair was used for incisional hernia repair but was associated with recurrence rates as high as 46%. To strengthen the abdominal wall and prevent the development of recurrences the additional implanttation of an alloplastic mesh is nowadays commonly used. Conventional hernia surgery as well as minimally-invasive surgery, introduced in the early 90s, make use of this mesh-technique and thereby showed marked reductions in recurrence rates. However, there are side effects associated with mesh-implantation. Therefore recommendations remain uncertain on which technique to apply for incisional hernia repair and which technique might, under specific circumstances, be associated with advantages over others.
3. Objectives
3.1 Medical questions
The goal of this report is to compare laparoscopic and conventional surgery with and without mesh for incisional hernia repair, regarding efficacy and medical safety. In order to do so, the following questions will be addressed from a medical standpoint:
What are the medical efficacy and safety of laparoscopic compared to conventional surgery without mesh-implantation?
What are the medical efficacy and safety of laparoscopic compared to conventional surgery with mesh-implantation?
Which techniques of mesh-implantation and -fixation (e. g. Onlay, Inlay, Sublay, IPOM, suture, and metal clips) are associated with advantages over other techniques?
Which factors (e. g. sex, age, recurrent hernia, hernia size, adiposity) are identifiable where certain techniques have advantages over other techniques?
3.2 Economic questions
The goal of this report is to compare laparoscopic and conventional surgery with and without mesh for incisional hernia repair, regarding cost effectiveness. In order to do so, the following questions will be addressed from an economic standpoint:
How to judge the cost effectiveness of the respective methods?
How to judge the transparency and the quality of the health economic studies?
How can policy decisions be derived from the gained research results?
What direct and indirect costs are reported in the literature?
Is further research activity required?
4. Methodology
Relevant publications were identified by means of a structured search of databases accessed through the German Institute of Medical Documentation and Information (DIMDI) as well as by a manual search. The former included the following electronic resources:
SOMED (SM78), Cochrane Library – Central (CCTR93), MEDLINE Alert (ME0A), MEDLINE (ME95), CATFILEplus (CATLINE) (CA66), ETHMED (ED93), GeroLit (GE79), HECLINET (HN69), AMED (CB85), CAB Abstracts (CV72), GLOBAL Health (AZ72), IPA (IA70), Elsevier BIOBASE (EB94), BIOSIS Previews (BA93), EMBASE (EM95), EMBASE Alert (EA08), SciSearch (IS90), Cochrane Library – CDSR (CDSR93), NHS-CRD-DARE (CDAR94), NHS-CRD-HTA (INAHTA) as well as NHS-EED (NHSEED).
The present report includes German and English literature published until 31.08.2005. The search parameters can be found in the appendix. No limits were placed on the target population. The methodological quality of identified studies was assessed, using the criteria recommended by the Scottish Intercollegiate Guidelines Network Grading Review Group and by the German Scientific Working Group technology Assessment for Health Care.
5. Results
5.1 Medical results
The literature search identified 693 medical publications of which 152 could be identified as relevant to the research question. Ten further publications have been identified through manual search, leaving a total of 162 medical studies. Of the 17 studies assessed to be relevant to our particular topic, including two systematic reviews, one HTA, one randomised controlled trial (RCT), and 13 cohort studies. Only one cohort study compared laparoscopic and conventional surgery with and without mesh-implantation for incisional hernia repair, while the remaining 16 studies compared laparoscopic and conventional surgery with mesh-implantation. The only study comparing laparoscopic and conventional surgery without mesh found substantial differences in terms of baseline characteristics between treatment groups. The outcome parameters showed decreased recurrence rates for the laparoscopic repair and similar safety of the procedures. Studies comparing laparoscopic and conventional surgery with mesh found similar outcome in terms of medical efficacy and safety with a trend towards lower recurrence rates, length of hospital stay and postoperative pain as well as decreased complication rates for laparoscopic repair in the majority of studies. The impact of the technique of mesh-implantation and mesh-fixation as well as the impact of certain patient related factors on the choice of technique has not been systematically investigated in any of the studies.
5.2 Economic results
Based on a systematic literature review 97 economic studies were identified. After studying the abstracts, 36 research papers were considered relevant and ordered to pore over. One more study was identified manually. Overall 37 entire economic research papers were considered. None of the economic studies matched the inclusion criteria. Therefore, the criteria economic evidence was loosened. Following that, five economic studies were identified and included.
Basically, there is no full economic evaluation focussing the relevant alternatives. Cost comparisons were available, even though only briefly attached to clinical research results. None of the studies primarily aimed to investigate costs or even effectiveness.
6. Discussion
In general, three operative techniques are available for incisional hernia repair: the conventional technique without mesh-implantation, the conventional technique with mesh-implantation and the laparoscopic technique. All identified studies suffer from significant methodological weaknesses, such as differences between treatment groups, mainly due to the non-randomised study design, small treatment groups causing low case numbers and lack of statistical power as well as the neglect of important risk factors or adjustment for those. Therefore, no conclusive differences could be identified concerning compared operative techniques, mesh-implantation and mesh-fixation techniques or certain risk factors. Only the comparison of laparoscopic and conventional technique with mesh provides some evidence for a trend towards similar or slightly improved outcome in terms of medical efficacy and safety for the laparoscopic technique. However, there is still a great need for further research to investigate these questions.
Basically, there is no full economic evaluation focussing on the relevant alternatives. Cost compareisons were available, even though only briefly attached to clinical research results. None of the studies primarily aimed to investigate costs or even cost-effectiveness.
7. Ethical, social and legal considerations
No ethical, social and legal aspects were identified in the literature.
8. Conclusion
When deciding on the choice of operative technique for incisional hernia repair, surgeons take various considerations into account, including patient characteristics, hernia characteristics and their own experience. The studies included in this HTA did not provide conclusive evidence to answer the research questions. Nonetheless, laparoscopic surgery demonstrated a trend towards similar or slightly improved outcome following incisional hernia repair. However, for more conclusive recommenddations on the choice of operative technique, high quality trials are required.
From the economic perspective, alternative methods are not yet assessed. Only five of the studies involve a cost analysis, though in an insufficient manner. None of the studies identified were laid out as a health economic evaluation. Hence, further research is strongly recommended.