Intraoperative, early postoperative, late postoperative complications.

The numbers in brackets reflect all the hernia repairs performed including the complicated hernias too (recurrence, after preperitoneal repair open or laparoscopic, incarcerated or irreducible hernias, scrotal hernias and hernias after open prostatectomy or bladder surgery).

Some intraoperative complications may be specific for TAPP repair like visceral or bowel injuries, some may be addressed to general anaesthesia (circulatory complications, hypercarbia) and some result from incorrect dissection or misinterpretation of the local anatomy or too generous use of monopolar cautery.

The overall complication rate in this huge series is very low and reflects an immense experience of a dedicated team with a very high caseload (>1000/year). Under average conditions including teaching institutions, we have to assume that the true complication rate is much higher. The impact of experience as demonstrated by the same team shows how important is the standardisation of a new procedure, improving the operative skills, improving the anatomical knowledge and adhering strictly to the principals of minimal invasiveness in any TAPP hernia repair. In other reports from the early days of TAPP, one can recognise the same phenomenon of injuries to nervus cutaneus femoris lateralis due to imperfect knowledge of anatomy.

To perform a TAPP repair, it needs the insufflation of 2–4 lt. of CO₂ to lift and expand the anterior abdominal wall to maintain the working space. This step carries a substantial risk of an injury to intra-abdominal structures.

Which is the safest and most effective method of establishing pneumoperitoneum and obtaining access to the abdominal cavity?

The safest and most efficient method of access is still controversial [1–4]. There are four ways on how to obtain access to the abdominal cavity:

(1) Open access (Hasson) (2) Veress needle to create pneumoperitoneum and trocar insertion without visual control (3) Direct trocar insertion (without previous pneumoperitoneum) (4) Visual entry with or without previous gas insufflation [7–12].

Amongst general surgeons and gynaecologists, the most popular method is the Veress needle [1]. Although the open approach seems to be the safest, it does not eliminate the entire risk of injury [5, 6] (level 2C). When using open approach palpation through the peritoneal aperture, to exclude adhesions is mandatory before inserting a blunt cannula [6].

From Catarci et al. [5]

Further development of trocar design, from cutting instrument (to diminish the necessary penetrating force) towards the dilating instrument, has reduced the complication rate of parietal (or intra-abdominal) haemorrhage and the risk of developing a trocar hernia.

According to IEHS Guidelines and its Update, cutting trocars should not be used anymore. The use of 10 mm trocars or larger may predispose to hernias, especially in the umbilical region or in the oblique abdominal wall (stronger evidence) (level 2B). Therefore, fascial defects of 10 mm or bigger should be closed (stronger evidence) (grade B).

Concerning the closure of trocar wounds ≥10 mm, I believe in closing the peritoneal layer too. The reason is the obvious difference in trocar hernia incidence in TAPP and TEP repair.

Poor knowledge of anatomy, not recognising the structures, wrong use of energy sources, impatience, lack of skills or too difficult dissection (e.g. after previous surgery) [16, 17] may lead to injury of big vessels, nerves, bowel, bladder, spermatic cord or spermatic vessels.

Major nerve injuries after laparoscopic hernioplasty have been reported, but the risk of this complication appears to be extremely low. In the early days of TAPP, these injuries reflected the lack of knowledge of the local anatomy or indelicate dissection.

The “triangle of pain” (lateral of spermatic vessels and below the iliopubic tract) as an area of nerves at risk had to be enlarged to about 1.5–2 cm above the iliopubic tract thanks to the brilliant anatomic study of Reinpold.

The incidence of sensory changes after a TAPP repair seems to be ten times lower than after an open repair (p < 0.001) [15].

Entering the abdominal cavity (with or without previous surgery) and during the preperitoneal dissection, there is an instant risk of bowel or bladder injury. Half of the big vessel injuries were reported to be caused by the second trocar! That means under visual control! Lack of force coordination or even worse lack of concentration may lead easily to a major complication. It is a great advantage of TAPP when compared to TEP that the procedure starts with existing working space. To move the long instruments in this space without endangering the fragile structures within is a must, but it is an ability developed after many laparoscopic operations. Even in easy repairs, the concentration must be maintained from the insertion of Veress needle till the last skin suture.

The chance to “look back” (from preperitoneal space to intraperitoneal space) during the dissection of the landing zone, especially in triangle of doom and triangle of pain, lets the operator control the bowel behind. Steeper Trendelenburg position may bring the bowel in safe distance.

Despite the fact that a urinary catheter is in general not recommended, in some complicated cases it may be of great value. Dissection after open prostatectomy or after previous prosthetic preperitoneal repair may become quite difficult. Not only the empty bladder, but the possibility of retrograde instillation (e.g. methylene blue) may be advantageous to detect and control eventual bladder injury.

In case of necessary adhesiolysis, any suspicion of serosal lesion must be scrutinised. Oversewn serosa tear is more secure than a missed one.

The adhesiolysis of hernia content is not advisable. The hernia sac (e.g. in sliding hernias) is mobilised in toto with the content during the preperitoneal dissection.

The most dangerous condition is the unrecognised enterotomy or delayed enterotomy. The latter mostly caused by inappropriate use of monopolar cautery with consecutive tissue necrosis and delayed onset of postoperative peritonitis. Therefore, even after an easy procedure, stay alert to any unusual symptom after a laparoscopic hernia repair.

The bigger the hernia sac is, the bigger the chance of development of a seroma formation.

In large indirect sacs, the recommended complete retraction may lead to higher incidence of haematomas and may compromise the blood supply to the testicle. The transection of the indirect sac and leaving the distal portion open shows higher incidence of seromas and may lead in later course to development of a pseudo-hydrocoele. Fixing the distal portion to the abdominal wall lateral to epigastric vessels seems to help to avoid the occurrence of seromas [26].

In larger direct hernias (M2-3), the incidence of seromas can be significantly reduced by inversion of transversalis fascia and fixation to Cooper’s ligament with tacks [18, 19] or using an Endoloop [24, 25]. This step diminishes the dead space for seroma formation but additionally obliterates the potential of mesh dislocation into previous hernia space.

Inversion of the transversalis fascia is associated with a statistically lower incidence of postoperative seroma, without increasing postoperative pain despite the use of one or two additional tacks [19].

Conclusion: The primary closure of direct inguinal hernia defects with a pre-tied suture loop during endoscopic TEP repair is safe, efficient and very reliable for the prevention of postoperative seroma formation, without increasing the risk of developing chronic groin pain or hernia recurrence.

POUR is probably of multifactorial origin. There is no general indication for preoperative catheterisation, and there are no clear predictive factors for postoperative retention. It is advisable that the patient empties the bladder before surgery. Full urinary bladder during a TAPP repair increases the risk of a bladder injury and can make the dissection even more difficult. In patients with expected technical difficulties (after previous abdominal, prostatic or bladder surgery) or extended operating time (bilateral scrotal, in learning curve), preoperative catheterisation should be considered.

Postoperative urinary retention is more frequent in endoscopic repairs (under general anaesthesia – GA) then in open hernia repairs under local anaestesia, possibly due to inhibitory effect of GA on bladder function [27].

Urinary retention may significantly prolong the hospital stay. With consequent approach towards possible POUR—preoperative emptying, restrictive fluid management in the early postoperative phase, early mobilisation and refrain from opioids—the incidence of retention can be as low as 0.5 % [28].

Conversions in TAPP are very rare. Hostile abdomen should be ruled out preoperatively as a relative contraindication for TAPP due to inadequate risk of bowel injury. However, even after uncomplicated appendectomy, cholecystectomy or C-section, one can encounter extensive omento-parietal adhesions. Depending on surgeon’s experience and the extent of adhesions, it is wise to convert early enough before damage is done. Unforced conversion to open anterior repair can lead to better results; forced conversion as an “ultima ratio” after serious injury lead to laparotomy and higher complications rate. Lack of overview can lead to missed enterotomy with all its consequences.