Catheter shaft and catheter and method for the production thereof

A catheter, comprising:

• a connector comprising a body;
• a longitudinal channel extending through the body;
• a diagonal channel through the body, wherein the diagonal channel comprises a diagonal channel opening fluidly connected to the longitudinal channel;
• a conical-shaped sealing element within the longitudinal channel, the conical-shaped sealing element extending distally beyond the diagonal channel, the conical-shaped sealing element defining a first lumen;
• a first tube defining an inflation lumen, wherein a proximal opening of the inflation lumen is distal of the diagonal channel opening and in fluid communication with the diagonal channel opening;
• a second tube attached and sealed to the conical-shaped sealing element, wherein a lumen of the second tube defines a continuation of the first lumen;
• a longitudinal weld seam extending from an outer surface of the second tube to an inner surface of the first tube;
• wherein the first tube and the second tube terminate proximally at a same longitudinal position;
• wherein sole access to the proximal opening of the inflation lumen is through the diagonal channel.