Inguinal hernia results from a hole or defect in the muscles, through which the peritoneum protrudes, forming the sac. Inguinal herniorrhaphy is one of the most common operations that general surgeons perform. Laparoscopic herniorrhaphy is being done at a time when laparoscopic cholecystectomy has shown definite benefits over the open technique. But unlike laparoscopic cholecystectomy, laparoscopic hernia repair is an advanced laparoscopic procedure and has a longer learning curve. In addition, TEP requires higher technical expertise for successful results
In the lower abdomen there are five peritoneal folds or ligaments which are seen through the laparoscope in umbilicus. These ligaments are generally overlooked at the time of open surgery.
1. One Median Umbilical Ligament
In the midline there is median umbilical ligament extends from the mid of urinary bladder up to the umbilicus. Median umbilical ligament is obliterated urachus.
2. Two Medial Umbilical Ligament one on either side
The paired medial umbilical ligament is obliterated umbilical artery except where the superior vesical arteries are found in the pelvic portion. The medial umbilical ligaments are the most prominent fold of the peritoneum. Sometime, hangs down and obscure the vision of lateral pelvic wall. These ligaments are important landmark for the lateral extent of the urinary bladder.
3. Two Lateral Umbilical Ligaments
Lateral to the medial umbilical ligament, the less prominent paired lateral umbilical fold contains the Inferior epigastric vessels. The inferior epigastric artery is lateral border of Hesselbach’s triangle and hence is useful landmark for differentiating between direct and indirect hernia. Any defect lateral to the lateral umbilical ligament is indirect hernia and medial to it is direct inguinal hernia.
The femoral hernia is below and slightly medial to the lateral inguinal fossa, separated from it by the medial end of the iliopubic tract internally and the inguinal ligament externally.
Important landmarks for extraperitoneal hernia dissection include the musculo-aponeurotic layers of the abdominal wall, the bladder, coopers ligament and the iliopubic tract. The inferior epigastric artery and vein, the gonadal vessels and vas deferens should also be recognized. The space of Retzius lies between the vesicoumbilical fascia posteriorly and the posterior rectus sheath and pubic bone, anteriorly. This is the space first entered in extraperitoneal repair of hernia.
1. TRIANGLE OF DOOM: The triangle of doom is defined be vas deferens medially, spermatic vessels laterally and external iliac vessels inferiorly. This triangle contains external iliac artery and vessels, the deep circumflex iliac vein, the genital branch of genitofemoral nerve and hidden by fascia the femoral nerve. Staple should not be applied in this triangle otherwise; chances of mortality are there if these great vessels are injured.
2. TRIANGLE OF PAIN: Triangle of pain is defined as spermatic vessel medially, the iliopubic tract laterally and inferiorly the inferior edge of skin incision. This triangle contains lateral femoral cutaneous nerve and anterior femoral cutaneous nerve of thigh. The staple in this area should be less because nerve entrapment can cause neuralgia.
3. CIRCLE OF DETH: This is also called as corona mortis and refers to vascular ring form by the anastomosis of an aberrant artery with the normal obturator artery arising from a branch of the internal iliac artery. At the time of laparoscopic hernia this vessel is torn both end of vessel can bleed profusely, because both arise from a major artery.
The surgeon should remember these anatomic landmarks and the point of mesh fixation should be selected superiorly, laterally and medially.
Indications of Laparoscopic Repair of Hernia.
The indications for performing a laparoscopic hernia repair are essentially the same as repairing the hernia conventionally. There are, however, certain situations where laparoscopic hernia repair may offer definite benefit over conventionalsurgery to the patients. These include:
- Bilateral inguinal hernias
- Recurrent inguinal hernias
In recurrent hernia, surgery failure rate is as high as 25 to 30 percent, if again repaired by open surgery. The distorted anatomy after repeated surgery makes it more prone to recurrence and other complications like ischemic orchitis. In recurrent hernia, the laparoscopic approach offers repair through the inner healthy tissues with clear anatomical planes and thus, a lower failure rate. In laparoscopic bilateral repair with three ports technique, there is simultaneous access to both sides without any additional trocar placement. Even in patients with clinically unilateral defect after entering inside the abdominal cavity there is 20-50 percent incidence of a contra lateral asymptomatic hernia being found which can be repaired, simultaneously, without any additional morbidity of the patient?
Contraindications of Laparoscopic Repair of Hernia
- Non-reducible, Incarcerated Inguinal Hernia
- Prior laparoscopic herniorrhaphy
- Massive Scrotal hernia
- Prior pelvic lymph node resection
- Prior groin irradiation
Advantages of Laparoscopic Approach
- Tension free repair that reinforces the entire myo-pectoneal orifice.
- Less tissue dissection and disruption of tissue planes
- Three ports are adequate for all type of hernias
- Less pain postoperatively.
- Low intra-operatively and postoperative complications.
- Early return to work.
Disadvantages of Open Method
- Requires 4 to 6 inches of incision at the groin.
- Generally very painful, because of muscle spasm.
- Considerable post-operative swelling of tissues in groin, around the wound.
- Requires cutting through the skin, fat, and good muscles in order to gain access for repair, which in itself causes damage.
- Frequent complications of wound hematomas, wound infection, scrotal hematomas and neuroma.
- Usually takes 6 to 8 weeks for recovery.
- Sometimes long term disability, may follow e.g. neuralgia, neuroma and testicular ischemia.
- Whether a flat mesh or a plug is used from the front, they don’t hold themselves in place; what holds them in place are stitches, so the strength of the repair still depends on the stitches, not so much on the mesh or plug.
- Bilateral inguinal hernias require 2 incisions, doubling the pain; or 2 operations.
- Recurrent inguinal hernias are very difficult to operate open, and more liable to complications.
- The size of mesh used in open methods is limited by natural fusion of muscles.
- All meshes and plugs shrink with time, and this works against all open methods.
Any method of repair must achieve 2 fundamental goals, removal of the sac from the defect and durable closure of the defect. In addition the ideal method should achieve these with the least invasion, pain or disturbance of normal anatomy. Laparoscopic repair in expert hands is now quite safe and effective, and is an excellent alternative for patients with inguinal hernia. It is confusion that laparoscopic repair is more complex and is not widely available. The public needs to be educated as to its advantages. All surgeons agree that for bilateral or recurrent inguinal hernias, laparoscopic repair is unquestionably the method of choice. The argument against its use for unilateral or primary inguinal hernias is unfounded if it is the best for bilateral or recurrent hernias.
Types of Laparoscopic Hernia Repair
- Many techniques were used to repair hernia like
- Simple closure of the internal rings
- Plug and patch repair
- Intraperitoneal onlay mesh repair
- Transabdominal preperitoneal mesh repair (TAPP)
- Total extraperitoneal repair (TEP)
The technique of transabdominal preperitoneal repair was first described by Arregui in 1991. In the Transabdominal Preperitoneal (TAPP) repair, the peritoneal cavity is entered, the peritoneum is dissected from the myopectineal orifice, mesh prosthesis is secured, and the peritoneal defect is closed. This technique has been criticized for exposing intra-abdominal organs to potential complications, including small bowel injury and obstruction.
The Totally Extraperitoneal (TEP) repair maintains peritoneal integrity, theoretically eliminating these risks while allowing direct visualization of the groin anatomy, which is critical for a successful repair. The TEP hernioplasty follows the basic principles of the open preperitoneal giant mesh repair, as first described by Stoppa in 1975 for the repair of bilateral hernias.
The general anaesthesia and the pneumoperitoneum required as part of the laparoscopic procedure do increase the risk in certain groups of patients. Most surgeons would not recommend laparoscopic hernia repair in those with pre-existing disease conditions. Patients with cardiac diseases and COPD should not be considered a good candidate for laparoscopy. The laparoscopic hernia repair may also be more difficult in patients who have had previous lower abdominal surgery. The elderly may also be at increased risk for complications with general anaesthesia combined with pneumoperitoneum.
If the patient is young or the hernia small, it does not matter how the hernia is repaired. Many surgeons agree that for bilateral or recurrent inguinal hernias, laparoscopic repair is unquestionably the method of choice.
Laparoscopic surgery is not recommended for big irreducible and incarcerated hernia. Hernia repair should not be performed under local anaesthesia. Small direct hernia can be performed under spinal Anaesthesia if TEP is planned but best anaesthesia for laparoscopic hernia repair is G.A.
Trans-abdominal Pre-peritoneal Repair of Inguinal Hernia
Position of Surgical Team
Surgeon stands towards the opposite side of the shoulder. Cameral assistant should stand either right to the patient or on the opposite side of the patient.
The Position of Port is Laparoscopic repair of trans-abdominal hernia repair should be again according to base ball diamond concept.
The telescopic port should be in umbilicus. A 10 mm umbilical port is used. Two other ports, usually 10 mm for dominant hand and 5 mm for non dominant hand, are placed lateral to the umbilicus. In a left sided hernia the right lateral port should be in left iliac fossa and left port in left hypochondrium so that both the instrument should make a manipulation angle of 60 degree. In right sided hernia surgery right port should move up towards hypochondrium and left port will come down to make the triangle.
Procedure of TAPP
After Access a diagnostic laparoscopy is performed to rule out any adhesion or other intra-abdominal lesion. All the important anatomical landmark of hernia surgery is identifies with the help of telescope and one atraumatic grasper. The defect should be seen carefully and if any content is present inside the sac it should be reduced gently. A sliding hernia of colon should be carefully reduced because chances of perforation of large bowel are more than other viscus. Any adhesion between bowel and omentum should be divided carefully using bipolar and scissors.
The next step of transabdominal preperitoneal repair of hernia is creation of preperitoneal space. Many surgeons like to do hydro dissection to create this preperitoneal space but it is easy to create with sharp dissection as well. The peritoneum is cut 4cm lateral to the outer margin of deep ring. The flap of peritoneum is separated from above downward as soon as it will reach at the site of internal ring the hernia sac will be encountered.
Dissection should be started with opening the peritoneum lateral to the medial umbilical fold in order to identify Cooper’s ligament. Stopa’s parietalization technique should be used for dissection of the spermatic cord from the peritoneum by separating the elements of the spermatic cord from the peritoneum and peritoneal sac.
In case of indirect defect the hernial sac has to be either gently dissected free or inverted or if it is completely adhered with the transversalis fascia and cord structure it can be transected. The important landmarks of laparoscopic hernia repair are the pubic bone and inferior epigastric vessels. Surgeons should use both blunt and sharp dissection and the sac is dissected off the anterior abdominal wall. After being reduced partially it is ligated using an endo-loop and then transected with scissors. In case of bilateral hernias, the procedure is repeated on the other side. The vas and spermatic vessels has been separated from sac. Once the sac is separated, the next step is separation of sac from cord structures and dissection for creation of proper lateral space for placement of mesh. Lateral limit of dissection is the antero-superior iliac spine while inferior limit laterally is the psoas muscle. Dissection should be avoided in the "triangle of doom" which is bounded medially by the vas deferens and laterally by the gonadal vessels. A large hernial sac creates multiple planes and it is easy for the beginners to get disoriented with sac vas and vessel. The best way to avoid this confusion is that surgeon should keep himself as close as possible to the outer surface of peritoneum. If the spermatic vessels are injured accidentally it can be clipped. Even if the testicular vessel is injured, the testes will get the blood supply from collateral vessels developed through cremasteric.
In direct hernias the creation of preperitoneal space is comparatively easy as there is no chance of injury of spermatic vessels and vas. The bulge in the transversalis fascia may be repaired by suturing or stapling.
The tacker application and application of electrosurgery should be very careful at the triangle of doom, triangle of pain and trapezoid of disaster. In case of massive complete indirect scrotal hernias, no attempt should be made to reduce the sac completely as it may increases the risk of testicular nerve injury and haematoma formation.
Placement of the Mesh
Criteria for Laparoscopic Mesh
- Non Absorbable
- Adequate size
- Adequate memory
A proline mesh of appropriate size, usually 15X15 cm should be taken and one corner of Mesh should be tailored. Mesh should be rolled and loaded backward in one of the port. Mesh is placed inside the abdominal cavity through 12mm port. If surgery is being performed by 10mm port only the port should be removed and rolled mesh should be introduced though the port wound directly. After introduction of mesh it is unrolled when it reaches in peritoneal cavity. Mesh is fixed medially over the Cooper's ligament and pubic bone using a tacker or anchor. Tailored corner of mesh should be positioned infero-medially. No lateral slit should be made in the mesh and it should not be fixed lateral to cord structures to prevent injury to lateral cutaneous nerve of thigh. The mesh in this position covers the direct, indirect and femoral defects. It is essential that mesh should extend below the pubic tubercle so that it covers the femoral orifice. Mesh should also extend medially to cover all the possible orifices of hernia. Laterally mesh should project at least 2 to 3 cm beyond the margin of deep ring. If mesh is not of appropriate size, the chance of recurrence is high. Sometime, surgeon may be disoriented and mesh is placed with its long axis vertical instead of transverse. If mesh is cut at one of the corner chances of this disorientation is minimum.
Implant for Fixing Mesh
Foe fixing mesh in hernia surgery many preloaded devices are available. Mesh is fixed medially over the Cooper's ligament and pubic bone using an implant.
Currently three popular brands of implants to fix the mesh are available. These are Tacker, Protack or Anchor. The comparative chart of these implant is shown in table below.
- ESS Endoanchor
- Tyco Protack
- Tyco Tacker
Number of Implants
Geometry of Implant
- Helical Fastener
- Helical Fastener
Port size required
Trigger fire orientation
- Release to deploy
- Depress to deploy
- Depress to deploy
After adjusting the mesh properly it should be fixed by stapling first its middle part three figure above the superior limit of the internal ring. With mesh duly stapled pneumoperitoneum is reduced to 9 mmHg. It is important to avoid pricking of the inferior epigastric artery or the testicular vessels. Intracorporeal suturing can also be used for fixation of mesh if surgeon has sufficient suturing skill.
Closure of the Peritoneum
After fixing the mesh properly the peritoneum flap is replaced over the mesh and it is closed either by staples or suture. It is important that mesh should be completely covered by the peritoneum. Ideally peritoneum should be opposed by overlap fashion and peritoneum defect is closed either by staples or by continuous suturing and Aberdeen termination.
Repair of Bilateral Inguinal Hernia
In laparoscopic surgery postoperative recovery of bilateral hernia is same as that of unilateral hernia. The technique of bilateral laparoscopic repair of hernia is same as that of unilateral hernia. Patients with bilateral hernia are good candidate of laparoscopy. The two sides may be repaired using two meshes but single long mesh also can be used and it is pushed across from one side behind the bladder, and across the inguinal orifice on the opposite side. The size of the mesh for bilateral hernia should be 30cm X 15cm. Surgeon should avoid twisting of mesh. After placing the mesh in bilateral hernia surgery it should look just like a bow tie.
Repair of Recurrent Inguinal Hernia
Recurrent laparoscopic hernia after open surgery is better to repair laparoscopically, because external anatomy is disrupted and open repair have more chance of recurrence. Laparoscopy is method of choice for recurrent hernia. The defect is usually direct and more than one in recurrent hernia. The result of laparoscopic repair is excellent even in case of multiple hernias.
Laparoscopic Hernia in Children
Laparoscopy has been tried in little children’s. Only closure of ring and herniotomy is possible in pediatric age group. The sac is simply inverted and tied internally. The care should be taken that the vas or vessels should not be caught in the ligature.
Ending of the Operation
At the end of surgery, the abdomen should be examined for any possible bowel injury or haemorrhage. The entire instrument should be removed and then all the port. Each port should be removed under direct observation through telescope. Ports larger then 10mm should be sutured. Telescope should be removed at last after releasing all the gas keeping in mind that last port should not be pulled without putting telescope or any blunt instrument in, to prevent entrapment of bowel or omentum and formation of adhesion or intestinal adhesion. Wound should be closed with suture, especially 10 mm wound.
Totally Extra-peritoneal Hernia Repair
The technique of totally extra-peritoneal repair (TEP) of inguinal hernia was described even before the TAPP technique; however, technical difficulties of working in closed space and anatomy with the limited working space hindered its popular acceptance. The effectiveness of this type of repair has been well established by the open operation of Stoppa.
Advantage of TEP
- Pneumoperitoneum is not required
- Less chance of dangerous vessel injury or bowel injury
- The view of groin is better for dissection around the neck of sac
- Continuity of peritoneum is not breached so need not to be closed
Disadvantage of Preperitoneal repair
- The identification of correct plane of dissection is difficult
- The landmarks of hernia dissection can only be identified when they are encountered
- Reduction of content of sac is difficult to ensure
- Sliding hernia is difficult to recognize from outside of sac
- If the sac is cut it is difficult to close it again
- In recurrent hernia extensive adhesion make the dissection difficult because peritoneum may be adherent to the under surface of scar.
- There is always a chance of breach of peritoneum continuity and this will reduce the view.
- Four ports generally are necessary for bilateral hernia surgery. Whereas, in TAPP only three ports are sufficient.
Preparation of the Patient
Preparation of the patient in totally preperitoneal hernia repair is same as of the trans abdominal hernia repair. Knowledge of the anatomy of the abdominal wall muscle and recognition of the transition zone that occur at the arcuate line of Douglas is very important for totally pre-peritoneal hernia repair.
Approach to Preperitoneal Space
In totally extraperitoneal repair of hernia, the main concern is to make an extraperitoneal space. The extraperitoneal space is made possible by the fact that the peritoneum in suprapubic region can easily be separated from anterior abdominal wall, thereby creating enough space for dissection.
A 2cm longitudinal skin incision is made just below the umbilicus 1cm lateral to the midline on the side of hernia. The incision is deepened down to reach up to the anterior rectus sheath. All the subcutaneous fat is cleared and the rectus is opened under direct vision. Two-stay suture on each leaf of rectus sheath is placed and the rectus muscle is retracted by two retractors downward towards symphysis pubis in an oblique fashion; we should never cross the posterior fascia of the rectus muscle while dissecting.
By fingered or swab towards the hernia dissection should perform carefully, preperitoneal space will be found below the arcuate line of Douglas.
Insertion of Port
A balloon dissector should be introduced with telescope and balloon is inflated for further dissection of the pre-peritoneal space. An11mm port is introduced without its sharp tip with a laparoscope in 30 degree. A Small pre peritoneal pocket is created by manipulating laparoscope in sweeping manner.
If balloon dissector is not available the glove finger can be tied around the suction irrigation instrument and can be used to create some preperitoneal space.
Sweeping Movement of Telescope
Once the telescope is placed properly a 10mm port is inserted under direct view approximately halfway between the symphysis pubis and the umbilicus. Another 5mm port should be placed two fingers below and medial to the right anterior iliac spine. If the secondary port site is not seen clearly though the telescope one can infiltrate the port site with local anaesthetic and look for the tip of the needle internally. This will insure the exact placement of port and allow the tip of trocar to be seen by telescope at the time of insertion.
Dissection of Preperitoneal Space and Cord Structures in TEP.
In totally extraperitoneal repair of hernia Stopa’s parietalization technique is used for dissection of the spermatic cord from the peritoneum by separating the elements of the spermatic cord from the peritoneum and peritoneal sac should be done. The dissection is started by tracing the inferior epigastric vessels towards the deep ring. The upper border of the hernia sac readily recognized because indirect hernia is lateral to the inferior epigastric vessels and direct hernia is medial to that.
As the inguinal region is approached, the dissection is continued all around the sac to encircle the neck. The surgeon should try to remain close to peritoneum and dissection continues medially to separate vas from the sac. Under the neck of the sac care should be taken to avoid injury of iliac vessels.
In case of direct inguinal hernia the dissection is carried out from above downwards and progressed medially to the inferior epigastric vessels. The direct sac is freed from the transversalis fascia. Dissection should be continued until the peritoneum has reached the iliac vessels inferiorly.
Care should be taken that any hole in peritoneum should not form otherwise it will be difficult to have good working space because the gas will escape into abdominal cavity. If the hole is made anyway it should be identified and enlarged this will equalize the pressure on both side of peritoneum and allows the peritoneum to drop back down due to gravity. A venting 5mm port or veress needle can be placed in the right upper quadrant at palmers point to decompress the abdominal cavity.
Introduction of Mesh in TEP
The technique of insertion of mesh in totally extraperitoneal repair of hernia is same as tat of trans abdominal preperitoneal. Mesh in appropriate size usually 15X15 cm is used. Mesh should be rolled and load backward in one of the port.
Mesh should be fixed by stapling first in its middle part three finger above the superior limit of the internal ring. In totally extraperitoneal repair some surgeon do not use staple, because peritoneum is not breached and once the gas from pre-peritoneal space is removed, it will place the mesh in its proper position. In 1 to 2% of cases of TEP conversion to open or TAPP may be necessary due to large peritoneal tear making the vision difficult or in the cases where content is not reduced completely.
Laparoscopic Repair of Femoral Hernia
Laparoscopic repair of femoral hernia is same as that of laparoscopic direct or indirect hernia. It can be performed by both TAPP and TEP methods. In case of Laparoscopic femoral hernia repair the sac should be carefully excised because rigid femoral ring make it difficult to mobilize the sac. The dissection should be careful because there is increased risk of injury of abnormal obturator artery on lateral to the sac. In femoral hernia defect is between the iliopubictract and pubic ramus and can be easily identified. Repair of the femoral canal should be done by approximating iliopubic tract to the Cooper’s ligament by proline stitches.
Ending of the Operation
At the end of surgery the abdomen should be examined for any possible bowel injury or haemorrhage. The entire instrument should be removed and then all the port. We generally use Vicryl for rectus and un-absorbable intra-dermal or Stapler for skin. Adhesive sterile dressing should be applied over the wound.
Complications of Laparoscopic Hernia Repair
Like any other laparoscopic procedures, complications have been recorded during the learning curve. The major problems include:
- Neurovascular injury
- Urinary tract injury
- Injury to vas
- Testicular complications
- Problems due to mesh.
The mechanism of recurrence can be related to lack of understanding of the difficult laparoscopic anatomy, wrong hernia repair technique or the wrong prosthesis. These include incomplete dissection without proper pocket formation, missed sac, migration of mesh due to small sized mesh which may be prone to displaced once fixed, inadequate fixation with rolling up of the mesh and haematoma formation leading to infection.
The complication of laparoscopic hernia repair can be summarized as follows:
- Immediate: Visceral Injury, Vascular Injury, Injury to Vas, Spermatic vessels
- Late: Bowel Adhesions to mesh, Intestinal Obstruction, Fistulization, Orchitis, Testicular atrophy, Nerve entrapment, Incisional hernia recurrence
The incidence of vascular injury has been documented to be about 0.5-1 percent and inferior epigastric artery is the one most commonly traumatized.
- Injury to Iliac Vessels: Chances of Mortality
- Inferior Epigastric Vessel: Haematoma
- Iliopubic vein and artery which traverse the lacunar ligament: Haematoma
- Injury to Spermatic vessels: Postoperative scrotal haematoma
Post-operative scrotal haematoma
Nerve Entrapment and Injury
The lateral cutaneous nerve of thigh and the femoral branch of genitofemoral nerve are the two nerves vulnerable to trauma due to indiscriminate placement of staplers lateral to the spermatic cord on the iliopubic tract.
- Injury of lateral cutaneous nerve injury
- Most common nerve injured is lateral femoral cutaneous nerve (2%): Hyperesthesia or Paraesthesia of upper aspect of thigh and hip.
- If pain start days after surgery will recover within 2-4 weeks (or Percutaneous steroid)
- If pain starts within 24 hour of surgery there is permanent nerve damage
- Cryotherapy with destruction of sensory branch is indicated
- Lifelong numbness
Nerve entrapment should be avoided in laparoscopic repair of Hernia
- Genitofemoral nerve injury
- Genitofemoral nerve injury (1%): Hyperesthesia or Paraesthesia of scrotum
- Not significant
- With time it will subside
- Migration of Mesh
- Rejection of Mesh (Rare)
- Bowel adhesion
Complete transaction of vas requires immediate anastomosis. Other complications include testicular pain, orchitis, epididymitis, swelling due to seromas or haematoma. The treatment is supportive and incidence of all these complications is similar to that in conventional surgery.
After some experience most cases of inguinal hernia can be treated laparoscopically. Several prospective randomized trials comparing open versus laparoscopic repair have reported. Reduced postoperative pain, earlier return to work and fewer complications and less chance of recurrences for the laparoscopic approach are some of the crucial advantages. Although the procedural cost for laparoscopic hernia repair is more compared to conventional repair but overall expense for open repair is high if we calculate number of working days lost and medication is taken into consideration. Data is now available which documents the totally extraperitoneal repair to have distinct advantage over the Trans-abdominal preperitoneal repair in terms of lesser postoperative complications and lower recurrence rate. TAPP has been stated to violate the peritoneal cavity with all its known possible complication of pneumoperitoneum, vessel or bowel injury. There is no doubt that the laparoscopic hernia repair is a proven technique and will become more popular over a period of time
Minimal Access Surgeon